Emergency Ultrasound: Principles and Practice

A03750-Frontmatter.qxd 9/8/05 1:29 PM Page iv 1600 John F. Kennedy Blvd. Suite 1800 Philadelphia, Pennsylvania 1910...

Author: Romolo Gaspari | J. Christian Fox

568 downloads 2232 Views 19MB Size Report

This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!
Report copyright / DMCA form

DOWNLOAD PDF

A03750-Frontmatter.qxd

9/8/05

1:29 PM

Page iv

1600 John F. Kennedy Blvd. Suite 1800 Philadelphia, Pennsylvania 19103-2899 EMERGENCY ULTRASOUND: PRINCIPLES AND PRACTICE Copyright 2006 by Mosby, Inc. All rights reserved.

ISBN-13: 978-0-323-03750-1 ISBN-10: 0-323-03750-X

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier’s Health Sciences Rights Department in Philadelphia, PA, USA: phone: (+1) 215 239-3804, fax: (+1) 215 239-3805, e-mail: [email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’. Notice Knowledge and best practice in this field are constantly changing. As new research and experience broaden our knowledge, changes in practice, treatment, and drug therapy may become necessary or appropriate. Readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of the practitioner, relying on their own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the Authors assume any liability for any injury and/or damage to persons or property arising out or related to any use of the material contained in this book. The Publisher Library of Congress Cataloging-in-Publication Data Gaspari, Romolo Joseph. Emergency ultrasound/Romolo Joseph Gaspari, J. Christian Fox, Paul R. Sierzenski.–1st ed. p.cm. ISBN 0-323-03750-X 1. Diagnosis, Ultrasonic, 2. Emergency medicine—Diagnosis. I. Fox, J. Christian. II. Sierzenski, Paul R. III. Title. RC78.7.U4G37 2006 616.07′543—dc22 2005041636 Acquisitions Editor: Todd Hummel Editorial Assistant: Martha Limbach

Printed in the United States of America. Last digit is the print number: 9 8 7 6 5 4 3 2 1

A03750-Frontmatter.qxd

9/8/05

1:29 PM

Page v

PREFACE

Emergency ultrasound is the offshoot of an imaging modality that has its roots in the specialty of radiology. Over time, ultrasound has migrated to a wide range of clinical practices such as obstetrics, cardiology, and vascular surgery. In the last decade, pioneers in emergency medicine have advanced the field of emergency ultrasound. From the first lonely fellowship, emergency ultrasound has evolved into a recognized core skill of graduating emergency residents. For a few of us, ultrasound has become integral to the practice of emergency medicine, and for others a useful adjunct in a busy emergency department. Over the next decade I expect we will see an explosion of ultrasound in the emergency department, intensive care unit, and primary care offices. This book will direct clinical sonographers in the common focused ultrasound protocols encountered in the emergency department, ICU, and clinic. This book was written by practicing emergency physician sonographers for physicians who are integrating emergency ultrasound into their clinical practice. It is a practical reference on how to acquire the images needed to perform a focused ultrasound. I am indebted to the initial ultrasound fellows and fellowship directors for their pioneering work that has made this book possible. Romolo Gaspari

v

A03750-Ch01.qxd

9/8/05

1:18 PM

Page 3

CHAPTER

Introduction to Emergency Ultrasound

1

Romolo Gaspari and Paul Sierzenski

OVERVIEW The goal of this book is to provide information and an approach on how to obtain, document, and integrate emergency ultrasound into your clinical practice. Specifically, we will show • Standardization of image documentation for both still images and video images • Tutorial on how ultrasound probe acquires images and how movement of the probe affects images seen on the ultrasound screen • Step-by-step information on how to obtain ultrasound images • Description of protocols for bedside ultrasound that answer routinely encountered clinical questions seen in emergent conditions • Examples of normal ultrasound images • Simplified drawings of all ultrasound images • Diagrammatic representation of ultrasound scanning planes • Examples of commonly encountered alternative ultrasound views resulting from unusual probe placement

BOOK ORGANIZATION Each chapter is organized to provide instruction on how to successfully integrate bedside ultrasound into clinical practice. Chapter sections include • Goal of protocol • General anatomy • Patient positioning • Equipment • Key ultrasound images • Landmarks • Image elements • Tricks of the trade • Partial view ultrasound images • Alternative ultrasound images • Ultrasound protocol techniques

3

A03750-Ch01.qxd

4

9/8/05

SECTION I

1:18 PM

Page 4

Introduction and Basics

ULTRASOUND IMAGE DRAWINGS Ultrasound image drawings accompany each description. • Simplified drawings showing only pertinent anatomy • Unified color-coded anatomic drawings and ultrasound sector drawings • Identification of common ultrasound artifacts

DEFINITIONS In General • Protocol – series of ultrasound views that answer a clinical question or that interrogate an organ or organ system • Image elements – portions of ultrasound images corresponding to anatomic or pathologic structures within body • Partial view ultrasound images – atypical or unusual ultrasound images that may contain some image elements needed for patient care but are missing crucial elements needed to complete ultrasound Directions or Probe Movements • Cephalad or superior – toward the head • Caudad or inferior – toward the feet • Deep or posterior – further from the anterior skin surface • Shallow or anterior – closer to the anterior skin surface • Sliding – moving probe parallel to probe indicator • Fanning – moving probe perpendicular to indicator • Rotating – turning probe in clockwise or counter-clockwise manner without moving probe on skin surface Descriptive Terms • Hyperechoic – increased brightness of a portion of ultrasound image (image is whiter) • Hypoechoic – decreased brightness of a portion of ultrasound image (image is darker) • Anechoic – lack of ultrasound echoes in a portion of ultrasound image (image is black) • Isoechoic – similar echo levels as surrounding images • Heterogeneous – uneven echo pattern within portion of ultrasound image • Homogeneous – even echo pattern within portion of ultrasound image • Cystic – anechoic structure with rounded edges

HOW TO THIS USE BOOK Each chapter provides step-by-step instructions on how to accurately acquire and record all ultrasound images needed to answer clinical questions. Anatomy • Drawings and descriptions to help identify and visualize anatomy in two and three dimensions • Two dimensions – anatomy as drawn on paper or seen on screen • Three dimensions – anatomy as encountered during ultrasound procedure • Understand how ultrasound probe movements affect imaging (Note: Only limited anatomy is depicted in this book. Additional textbooks on anatomy are required prior to using this book.)

A03750-Ch01.qxd

9/8/05

1:18 PM

Page 5

CHAPTER 1


Patient Positioning • Identify proper patient positioning for obtaining ultrasound images Equipment • Proper probe selection for obtaining ultrasound images Ultrasound Images • Locate and identify anatomy needed to accurately frame ultrasound image • Identify image elements where typical pathologic findings are located (where to look on ultrasound image to find typical pathology) • Tricks of the trade to help avoid common pitfalls Partial View Probe Positioning • Suboptimal images that must be combined with other partial view images to complete an ultrasound protocol • Multiple partial views required in some patients to complete protocol • Drawings and labels corresponding to partial view images • Allows identification of suboptimal views and identification of missing image components Ultrasound Protocol • Identify probe location, orientation, and probe movements for obtaining ultrasound images • Identify ultrasound planes of imaging for obtaining ultrasound images • Identify still image sequence or videotape images required for documenting lack of pathology

CONCEPT OF EMERGENCY ULTRASOUND • Performance of ultrasound imaging by clinicians directly involved in patient care or sonographers working closely with medical staff • Acquisition of images, interpretation of images, and integration into patient care performed by single individual • Limited protocols focusing on questions common to emergent conditions • Image acquisition occurs at site of patient care (bedside imaging) • Focuses on yes–no questions important to emergent conditions • Immediate integration of image interpretation with history, physical exam, laboratory, or additional imaging findings • Non-protocol–driven ultrasound to assist in procedures performed by the clinician

ISSUES IN EMERGENCY ULTRASOUND • Performing an ultrasound should not delay performing potential life-saving procedures Example: Holding a patient in the emergency department solely to perform a FAST (focused assessment sonography of trauma) exam when vital signs are rapidly deteriorating • Repeat ultrasounds may be appropriate when patient condition changes • In many emergent situations lack of patient prep (i.e., fasting, bladder filling) may result in decreased image quality or inability to obtain interpretable images

5

A03750-Ch01.qxd

6

9/8/05

SECTION I

1:18 PM

Page 6


• In some situations, especially when first beginning to use ultrasound, the technology performs better to include a pathologic state (positive predictive value) rather than exclude it (negative predictive value) (e.g., it is easier to identify epididymitis than to exclude testicular torsion) • In some emergent situations the usual ultrasound windows (place on body to put probe) are not accessible and alternative views must be used Example: It may be difficult to obtain a parasternal long cardiac view in a person with a pneumothorax

PATIENT DISCLOSURES • When initiating an emergency ultrasound during your training phase, inform the patient that you may need to re-image the object of interest with additional imaging [e.g., a stable patient with a positive FAST may get a CAT (computerized axial tomography) scan or a patient with a limited ultrasound of the heart may get an echocardiogram by cardiology] • Avoid using the terms “formal,” “real,” or “better” as a descriptor of later ultrasounds performed by radiology, cardiology, or OB/GYN. Use the term “confirmatory” or “consultation” (e.g., “Mrs. Jones I was not able to obtain the information I need to help treat you. I need to send you to radiology for additional confirmatory studies”). • Avoid using common descriptors such as “normal” or “okay”; this may be interpreted by the patient beyond what you intend. Describe for the patient only the yes–no question you are trying to answer (e.g., do not say the heart looks “normal”; instead tell the patient there is “no pericardial effusion, or fluid, around the heart.” Do not say the baby looks “okay”; instead say there is a “pregnancy within the uterus with a heart beat”). • Do not provide patients with still images unless this is agreed upon with other consultants for follow-up

GENERAL CONCEPTS OF ULTRASOUND IMAGING • • • •

Practice obtaining ultrasounds that match images in this textbook Practice identifying normal anatomy in ultrasound images Practice optimizing image quality by maximizing machine controls Fill screen area with objects of interest

Area of interest

Wasted screen space

Depth set too deep

A03750-Ch01.qxd

9/8/05

1:18 PM

Page 7

CHAPTER 1


• Center area of interest in middle of screen Area of interest

Probe position too caudal

• Any anatomic structure of interest should be imaged in at least two planes that are perpendicular to each other (transverse and longitudinal) • Any pathologic (or suspected pathologic) structure should have imaging attempted in at least two planes (transverse and longitudinal)

ULTRASOUND TECHNIQUE • A full discussion of techniques to optimize image quality is beyond the scope of this textbook • Not all ultrasound machines have the same names for components used to maximize images. Become familiar with controls and settings provided by your machine. • Select proper ultrasound probe or probe setting using megahertz setting appropriate for level of imaging • Higher frequency ultrasound probes for superficial imaging • Lower frequency ultrasound probes for deeper imaging • Adjust depth of imaging to localized area of interest to center of ultrasound screen – “maximize screen real estate” • Adjust near and far gain (depth gain) setting to equalize image brightness and maximize edge delineation • Decrease power settings to lowest available setting at which details are easily seen • Adjust focus to correspond to area of greatest interest on the ultrasound screen • Probes with similar megahertz settings but different crystal arrangement provide different imaging capabilities • Tissue harmonic imaging (THI) is a setting that toggles on and off and may improve imaging capabilities • For many machines, using color Doppler imaging will decrease temporal resolution (making the frame rate look choppy)

7

A03750-Ch01.qxd

8

9/8/05

SECTION I

1:18 PM

Page 8


IMAGE DOCUMENTATION: STILL IMAGES VS. VIDEO IMAGES Still Images (Pro) • Framing of image occurs before image archiving (i.e., first you find the “perfect image”; then hit record) • Easier to identify intended images during quality assurance image review (i.e., only intended images are archived) • No external equipment is required to review still images • Less expensive to record ultrasounds as paper or electronic stills • Less cumbersome to set up still image quality assurance process • False-negative ultrasounds with adequate images but inappropriate interpretation are detected during the quality assurance (QA) process Example: A false-negative FAST read initially as negative that shows free fluid can be re-read as a true positive during QA Video Images (Pro) • Easier for quality reviewer to identify errors in imaging technique of ultrasonographer • Easier to document multiple images during ultrasound • Image archival more representative, better documentation of entire ultrasound • Less likely to miss documentation of pathology • Single-image representation of an ultrasound can miss pathologic findings • False-negative ultrasounds due to inappropriate interpretation are detected during QA process • Videotape review allows a tighter QA process which better identifies poor technique and gaps in knowledge and also provides an opportunity for education during tape review • Easier to accurately interpret ultrasound despite atypical or unusual views • Less complicated recording process results in fewer unrecorded ultrasounds in a busy emergency department • Recording when study begins and ends allows QA review to perform “indirect observation” of scanning performance and technique in real time. This can allow greater detail in feedback to the physician learning ultrasound as the QA review can note where difficulties were occurring (e.g., scanning duodenum for 5 minutes before identifying the gallbladder). Although still image recording of ultrasounds may be less expensive and easier to initiate as a QA process, the positives of videotaping all ultrasounds may outweigh the negatives. Clinicians who perform bedside ultrasound will tend to perform fewer and more varied ultrasounds than dedicated ultrasound sonographers in the radiology, cardiology, gynecology, or other specialty suites. This is the nature of emergency ultrasound, and highlights why a tighter videotape QA process may better identify individuals who require further training in the performance as well as interpretation of clinical bedside ultrasound. Still image QA may be appropriate in situations where clinicians are more experienced, perform a greater number of ultrasounds, videotape review is not technically feasible, or where only a few clinicians perform ultrasound.

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 9

CHAPTER

Basic Mechanics of Acquiring Ultrasound Images

2

Romolo Gaspari

There are four basic movements of the ultrasound probe that allow proper imaging. Every ultrasound probe has an indicator that provides a basic orientation. The orientation of the probe is indicated by a mark on the ultrasound screen. The four basic movements of the ultrasound probe are

• Movement in-line with the ultrasound probe indicator—think of “sliding along” the image • Movement perpendicular to the ultrasound probe indicator—think of “fanning through” the image • Rotation of the probe—think of “spinning through” the image • Movement along the axis of the probe (i.e., increased pressure on the patient’s skin)—think of “pushing toward” the image • Rocking movement without moving the probe (i.e., “heel-toeing movement”) Each of these movements causes entirely different results on the images being acquired. To make it more complicated, the orientation of the probe affects the results of moving the probe.

9

A03750-Ch02.qxd

10

9/8/05

SECTION I

1:18 PM

Page 10


ULTRASOUNDING AN EGG: PROBE MOVEMENTS IN THE ABSTRACT Throughout this chapter, there will be examples of ultrasound probe movements and how they interact with the abstract shape of an ordinary egg. By using the shape of an egg, you will better understand how moving the probe affects the images you view on the screen.

Outside of Egg

Inside of Egg

Initial Orientation It is critical to understand where you are starting from. The ultrasound probe emits sound in a very narrow flat plane like a fan. A probe located at the epigastrium can be moved toward the umbilicus with quite different results depending on which way the indicator is located. With the indicator oriented toward the patient’s head, the plane of imaging is the long axis of the body. This same location on the body with the indicator toward the patient’s right side produces a plane of imaging that is the short axis of the patient’s body.

Indicator

Sound Wave

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 11

CHAPTER 2


11

A03750-Ch02.qxd

12

9/8/05

SECTION I

1:18 PM

Page 12


Orientation of the Egg The egg has two true axes, unlike the human body which has three. The two axes are longitudinal and transverse. Any axis that is not long or transverse is oblique. The third axis of the human body is coronal, which in the egg is the same as longitudinal, just turned on its side.

Long Axis 2D

Short Axis

Oblique Axis

Long Axis 3D

Coronal Axis

These views are obtained by orienting the probe with the indicator toward the “tip” of the egg or the “side” of the egg. Imagine cutting a hard-boiled egg along its longest axis and pulling the two halves apart to look at the yolk. This is what you are doing with the ultrasound beam when you are viewing it in the long axis. When cutting the egg in the long axis, you may have a slice with yolk in it or you may not.

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 13

CHAPTER 2

Slice # 2


Slice #4

The short axis is just like cutting the egg into round segments and seeing if you have any yolk in the segment. In the diagram below, the first three slices of egg have no yolk in them but the next three slices have yolk in their center.

Slice #2

Slice #5

13

A03750-Ch02.qxd

14

9/8/05

SECTION I

1:18 PM

Page 14


A Comment on Orientation When commenting on the orientation of an image, the orientation refers to the object of interest, not necessarily the patient’s body. Although some organs are oriented with the axis of the body (i.e., aorta), many are not (i.e., cardiac). Some organs have a variable orientation and are patient dependent (i.e., gallbladder). Therefore you may have a long axis view of the gallbladder that is actually oblique to the patient’s body. This is still described as the long axis view of the gallbladder. Sliding Along the Image Movements of the probe toward the patient’s feet will have two different effects depending on which way the probe is oriented. Moving along the axis of the probe orientation causes the objects that you are viewing to “slide” across the screen. The same thing is true if you are moving the probe from the patient’s right side to patient’s left side, with the orientation in transverse. The important fact is that you are moving parallel to the orientation of the probe.

Probe Movements

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 15

CHAPTER 2


Probe Movements

Images on Screen

15

A03750-Ch02.qxd

16

9/8/05

SECTION I

1:18 PM

Page 16


Sliding Along the Egg If the indicator is pointing the same direction as the probe is moving, the objects on the screen will remain unchanged in character but will move across the screen. Sliding the probe to the right will move the view from #1 to #2.

2D View

View #1

View #2

Fanning Through an Image Doing the same movements with the probe (i.e., sliding toward the patient’s feet) but changing the probe orientation to the patient’s right causes different results. This movement will cause a “fanning through” of the objects on the screen. By moving the probe perpendicular to the orientation of the probe you are moving the ultrasound waves through the patient’s body like a tennis racquet through the air. In the following example, you are viewing the ultrasound wave end on (like the edge of the tennis racquet). Moving the probe down the patient’s side with the orientation in transverse causes the kidney to “shrink” as you scan from the thicker middle to the thinner end of the kidney.

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 17

CHAPTER 2


Probe Movements

Images on Screen

17

A03750-Ch02.qxd

18

9/8/05

SECTION I

1:18 PM

Page 18


Fanning Through the Egg By moving the probe perpendicular to the orientation of the probe the location of the objects on the screen does not change, but the size of the object changes as the wave of sound passes through it.

3D View

View #1

2D View

View #2

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 19

CHAPTER 2


Rocking the Probe You may also “fan through” a patient or “slide along” without actually moving the probe on the skin surface. Rocking the probe back and forth without moving the contact point with the patient’s skin accomplishes the same effect as moving the entire probe up and down. Rocking in-line with the probe orientation will cause the images to slide back and forth, while rocking perpendicular to the orientation causes “fanning through.”

or

19

A03750-Ch02.qxd

20

9/8/05

SECTION I

1:18 PM

Page 20


In either of the above ultrasounds, the entire kidney is scanned; however in the first one the probe is moved, while in the second the probe is rocked.

vs.

Slight rocking movements of the probe have a different effect. When using a curved probe not all of the face of the probe may touch the patient’s skin. By slightly rocking back and forth you bring that area of the probe’s face in contact with the patient. This may be useful in cases where movement of the probe is constrained by external objects such as electrocardiogram (ECG) leads, tubing, bed rails, or skin folds.

A03750-Ch02.qxd

9/8/05

1:18 PM

Page 21

CHAPTER 2


Rocking Through the Egg By keeping the contact point of the probe stationary on the surface of the egg but rocking the handle of the probe back and forth, you fan the ultrasound plane through the egg. This, however, is only true if the rocking is perpendicular to the orientation of the probe.

View #1

View #2

Note: If you have a choice between rocking the probe and moving the probe to get the image, then move the probe. The best images are obtained when the sound waves are perpendicular to the object being imaged.

21

A03750-Ch02.qxd

22

9/8/05

SECTION I

1:18 PM

Page 22


Rotating the Probe Without moving the probe on the patient’s skin but rotating it 90 degrees will cause a shift in orientation. This can be thought of as “spinning through” the image. Note: Turning the probe 180 degrees will simply invert the image on the screen.

Rotation

Probe Movements

A03750-Ch02.qxd

9/8/05

1:19 PM

Page 23

CHAPTER 2


Images on Screen

As an example, think of the aorta in a longitudinal plane with the indicator toward the patient’s head then rotate the indicator counterclockwise until it points to the patient’s right side. The aorta is now in a transverse plane. Note: All points in between longitudinal and transverse are termed “oblique” and are formed any time the probe is rotated to an axis that is not longitudinal or transverse (to the item of interest, not necessarily the patient’s body). Rotating Through the Egg When the probe remains stationary on the surface of the egg but is rotated 90 degrees, the image on the screen will change from longitudinal or long axis to transverse or short axis.

23

A03750-Ch02.qxd

24

9/8/05

SECTION I

1:19 PM

Page 24


Pushing In on the Probe By increasing pressure of the probe on the patient’s skin you will move the probe toward the objects on the screen. The closer you are to an object the better the image quality will be, but increased pressure may be uncomfortable to the patient. It is very useful to get closer to the object of interest and displace something that was between the probe and the object of interest (typically the bowel). However, it is not always possible to displace the objects between the probe and what you are looking at.

Probe Movements

A03750-Ch02.qxd

9/8/05

1:19 PM

Page 25

CHAPTER 2


Images on Screen

25

A03750-Ch02.qxd

26

9/8/05

SECTION I

1:19 PM

Page 26


Pushing In Toward the Yolk By putting axial pressure on the probe you do not change the size of the objects on the screen, but you move the objects on the screen closer to the top of the screen.

Probe Position 1

Probe Position 2

View #1

#2 View #1

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 29

CHAPTER

Focused Assessment Sonography of Trauma (FAST) Scanning Protocol

3

Romolo Gaspari

GOAL OF THE FAST EXAM Demonstrate free fluid in abdomen, pleural space, or pericardial space.

EMERGENCY ULTRASOUND APPROACH The focused assessment of sonography in trauma is unique for ultrasounds performed in the emergency department as it is designed as a screening assessment for patients involved in penetrating or blunt trauma. Although it is possible to use ultrasound to determine solid organ injury, the FAST scan is designed as a screening tool for peritoneal blood and should be used as such. Once the initial screening has been accomplished, it is possible to return to areas of interest and more fully evaluate for solid organ injury, but this should not impede patient care. Other imaging modalities are better suited to determining solid organ injury (i.e., CAT scan).

29

A03750-Ch03.qxd

30

9/8/05

SECTION II

1:19 PM

Page 30

Thoraco-Abdominal Protocols

ANATOMY The anatomy of interest in the FAST scan covers three areas of the abdomen and one of the thorax. Right Upper Quadrant Liver Kidney Diaphragm Morison’s pouch (potential space between liver and kidney) Left Upper Quadrant Spleen Kidney Diaphragm Splenorenal recess (potential space between spleen and kidney) Suprapubic Bladder Uterus Vesicouterine space or anterior cul-de-sac (potential space between bladder and uterus) Rectouterine space or posterior cul-de-sac (pouch of Douglas) (potential space between uterus and rectum)

Liver Kidney

Spleen Morison's pouch

Kidney

Vesico-uterine pouch

Bladder

Pouch of Douglas

Subxiphoid/Parasternal Liver Diaphragm Heart Pericardial space (potential space around heart)

Uterus

Diaphragm

Heart

Liver

The anatomy of the abdomen during the FAST exam is unique in that the area of interest is the interface between the various abdominal or chest organs. The organs of three views of the FAST scan are used to identify the potential peritoneal spaces, but the first view identifies the pericardial space.

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 31

CHAPTER 3


PATIENT POSITION Supine As a majority of patients are scanned following trauma, these patients will be “boarded and collared” with cervical spine and long board immobilization. There may be limited opportunity to reposition the patient secondary to concerns for cervical spine injury. In other words, the patient will be flat on his or her back and cannot be moved.

TRANSDUCER 3.0 to 5.0 MHz Tricks of the Trade • Deep breathing – Moves liver or spleen inferiorly and flattens the diaphragm, bringing the cardiac window closer to the subxiphoid region. • Trendelenburg – Increases likelihood of detecting small amounts of fluid by bringing the fluid away from the air-filled bowel and into a space that is easier to view sonographically (i.e., splenorenal and hepatorenal windows). • Infuse fluid in bladder catheter – Displaces bowel and creates a sonographic window to check for free fluid lateral and posterior to the bladder.

SX

ULTRASOUND IMAGES FAST Essential Images • Subxiphoid • Right upper quadrant (RUQ) • Left upper quadrant (LUQ) • Suprapubic (sagittal and transverse)

RUQ

SP

FAST Optional Images • Right costophrenic angle • Left costophrenic angle • Parasternal long view of heart

LUQ

PSL

RSub C

LSub C

31

A03750-Ch03.qxd

32

9/8/05

1:19 PM

SECTION II

Page 32


FAST: SUBXIPHOID (LONG AXIS OR SHORT AXIS) Landmarks • Liver–cardiac interface • Cardiac motion Liver Pericardial space Heart

Long Axis (of Heart)

Liver

Pericardial space Heart

Short Axis (of Heart)

Image Elements • Liver–cardiac interface Tricks of the Trade • A distended stomach following an endotracheal intubation will prevent an adequate view of the pericardium. Repeating the subxiphoid view following the placement of a nasogastric tube may improve image quality. • Have the patient take a deep breath and hold it if possible. This will flatten the diaphragm, bring the heart closer to the probe, and improve the image. • Advance the probe laterally along liver margin until the heart appears on the screen. This uses the liver as a window to improve visualization of the pericardium. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 33

CHAPTER 3


Too Close to Xiphoid Process Liver dominates view Incomplete view of heart

Liver

Pericardium Heart

Too Far from Xiphoid Process Liver dominates view No or incomplete view of heart

Liver

Bowel

Diaphragm

Too Far Right Liver–pulmonary interface No heart in view

Liver Lung Kidney

33

A03750-Ch03.qxd

34

9/8/05

SECTION II

1:19 PM

Page 34


Too Far Left No liver in image No heart in view Stomach gas obscures view

Spleen Stomach

FAST: RIGHT UPPER QUADRANT Landmarks • Liver–kidney interface

Morison's pouch Diaphragm

Kidney (inferior pole)

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 35

CHAPTER 3


Image Elements • Liver–kidney interface • Diaphragm • Inferior pole of kidney Tricks of the Trade • On most patients it will be necessary to slide the probe toward the head to obtain more diaphragm, and toward the feet to get down to the lower pole. • Rib shadows represent missing information that prevents you from obtaining all the necessary information on one static image. Rather, think of it as a dynamic process that involves “seeing around” the ribs to obtain all the necessary information. • With practice, your mind will eventually “subtract out” the rib shadows as you manipulate the probe and as the patient breathes in and out. • Retroperitoneal blood may be visualized “deep” to the kidney. • When performing a FAST exam do not be distracted by pathology in other organs unrelated to the traumatic event (e.g., mild hydronephrosis in the kidney).

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Liver dominates view Incomplete view of Morison’s pouch Missing inferior tip of kidney, or Missing inferior tip of liver, or Excessive view of lung

Kidney Liver Spine

35

A03750-Ch03.qxd

36

9/8/05

1:19 PM

SECTION II

Page 36


Too Caudad Kidney on left of screen Incomplete view of Morison’s pouch No view of diaphragm, or Loops of bowel dominate image

Liver

Kidney

Too Medial Liver–bowel interface dominates screen No view of Morison’s pouch No view of kidney (+/–) Vena cava or aorta in view

Liver

Bowel

Diaphragm

Too Lateral or Too Posterior Kidney dominates image Limited view of Morison’s pouch No view of diaphragm

Liver

Kidney

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 37

CHAPTER 3


FAST: LEFT UPPER QUADRANT Landmarks • Liver–spleen interface

Spleen (inferior tip)

Kidney Diaphragm

Image Elements • Liver–spleen interface • Diaphragm • Inferior pole of kidney • Inferior tip of spleen

Tricks of the Trade • Poor images usually result from approaching the LUQ from too far anterior. In the emergency department we rarely have the luxury of a fasting patient during a trauma. A full stomach will obscure much of the kidney–spleen interface. • Most kidneys are more posterior and superior than one might think. If you do not see the kidney, move more posterior and superior. • Be careful of calling free fluid around the stomach. The food, fluid, gas interface in the stomach from recent eating may simulate free fluid. This will not extend to the inferior spleen which is the most common area of a positive FAST scan in the LUQ view. • An intercostal view of the spleen–kidney interface will usually have some rib shadows. Rotating the probe 5 to 10 degrees clockwise may remove the shadow and improve your view. • Perirenal fat may appear as a hypoechoic area between the kidney and spleen but will contain some internal echoes.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

37

A03750-Ch03.qxd

38

9/8/05

SECTION II

1:19 PM

Page 38


Too Cephalad Pulmonary air obscures part of view Excessive view of lung Spleen on right of screen

Spleen Kidney Diaphragm Lung

Too Caudad Kidney on left or center of screen No diaphragm in view

Spleen (inferior tip)

Kidney

Too Medial (Anterior) Stomach obscures view Kidney not in view

Spleen Stomach

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 39

CHAPTER 3


Too Posterior Kidney dominates image Limited view of spleen–kidney interface No view of inferior tip of spleen Spleen Kidney

Diaphragm

Too Shallow Kidney dominates image No inferior tip of spleen No view of diaphragm

Spleen Kidney

SUPRAPUBIC Landmarks • Bladder–uterine interface • Bladder–bowel interface Male Bladder Long Axis

Bladder Bowel

39

A03750-Ch03.qxd

40

9/8/05

SECTION II

1:19 PM

Page 40


Male Bladder Transverse Axis

Bladder

Female Bladder Long Axis

Bladder Vesico-uterine space Recto-uterine space Uterus

Female Bladder Short Axis

Bladder Vesico-uterine space Uterus Recto-uterine space

Image Elements • Outline of bladder • Uterine silhouette (female)

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 41

CHAPTER 3


Tricks of the Trade • Performing the suprapubic ultrasound following a bladder catheterization is extremely difficult. Either perform prior to bladder catheterization or refill bladder with saline. • Reverse Trendelenburg will collect the available fluid in the pelvis and increase the likelihood that it will be identified. (Note: This is rarely needed.) • Through transmission of sound through the bladder may result in the area behind the bladder being “over gained” or being too white, which can result in false negatives. This should be corrected by adjusting the time gain compensation (TGC). • Fluid-filled bowel loops can appear as dark shapes in the pelvis but should not demonstrate the sharp angles seen with free fluid. This is easier to determine in the short axis view by imaging the bowel loops superior to the bladder. • Blood clots within the lumen of the bladder may appear as mobile echogenic shapes or debris.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad or Angle Too Steep No bladder in image, or Bladder on right of screen Bowel dominates view

Bowel

Bladder

41

A03750-Ch03.qxd

42

9/8/05

SECTION II

1:19 PM

Page 42


Angle Too Shallow Pubic symphysis obscures view Nonvisualization of internal structures

Pubic symphysis Bowel

Too Caudad Pubic symphysis partially obscures view Bladder on left of screen

Pubic symphysis

Bladder

Too Far Right or Left Bladder off-center (transverse) Small view of bladder (long) Bowel dominates view

Bowel

Bladder

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 43

CHAPTER 3


Alternative or Unusual Views Costophrenic angle (right) Similar to RUQ too high

Liver Lung Kidney

Costophrenic angle (left) Similar to LUQ too high Spleen Bowel Kidney Lung

Suprapubic during catheter insertion

Bladder Catheter Bowel

43

A03750-Ch03.qxd

44

9/8/05

SECTION II

1:19 PM

Page 44


Parasternal long view of pericardium

Pericardial space

Heart

Aortic root

Papillary muscle

ULTRASOUND PROTOCOL TECHNIQUE Still Image Protocol RUQ – Sagittal plane, anterior Transducer at costal margin or lower intercostal spaces Right anterior axillary line Indicator toward patient’s head Angle probe slightly medial

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 45

CHAPTER 3


RUQ – Coronal plane, lateral Transducer at costal margin or lower intercostal Right middle axillary line Indicator toward patient’s head Angle probe slightly posterior

45

A03750-Ch03.qxd

46

9/8/05

SECTION II

1:19 PM

Page 46


Subxiphoid – Transverse plane, anterior Transducer at costal margin Midline abdomen, subxiphoid Indicator toward patient’s right side Angle probe toward right scapula

LUQ – Coronal plane, lateral Transducer at left intercostal Left posterior axillary line Indicator toward patient’s head Angle probe anterior

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 47

CHAPTER 3


Suprapubic – Sagittal plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s head Angle probe inferior

47

A03750-Ch03.qxd

48

9/8/05

SECTION II

1:19 PM

Page 48


–Alternative– Suprapubic – Transverse plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s right Angle probe inferior

Optional Still Images Parasternal long view of pericardial space Oblique plane, anterior Transducer at intercostal space Lateral to sternum, left side Indicator toward patient’s right shoulder Probe perpendicular to chest wall

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 49

CHAPTER 3


Costophrenic angle, right Coronal plane, lateral Transducer at costal margin Right middle axillary line Indicator toward patient’s head Angle probe toward patient’s head

49

A03750-Ch03.qxd

50

9/8/05

SECTION II

1:19 PM

Page 50


Costophrenic angle, left Coronal plane, lateral Transducer at costal margin Left middle axillary line Indicator toward patient’s head Angle probe toward patient’s head

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 51

CHAPTER 3


ULTRASOUND PROTOCOL TECHNIQUE Videotape Protocol RUQ – Starting point, sagittal plane, anterior Transducer at costal margin or lower intercostal Right anterior axillary line Indicator toward patient’s head Angle probe slightly medial RUQ – Taping protocol Focus on renal–liver interface Sweep medial to lateral Include view of diaphragm Include view of inferior kidney

–Alternative– RUQ – Starting point; coronal plane, lateral Transducer at costal margin or lower intercostal Right middle axillary line Indicator toward patient’s head Angle probe slightly posterior RUQ – Taping protocol Focus on renal–liver interface Sweep probe anterior to posterior Include view of diaphragm Include view of inferior kidney

51

A03750-Ch03.qxd

52

9/8/05

SECTION II

1:19 PM

Page 52


Subxiphoid – Starting point, transverse plane, anterior Transducer at costal margin Midline abdomen, subxiphoid Indicator toward patient’s right side Angle probe toward right scapula Subxiphoid – Taping protocol Focus on heart–liver interface Sweep anterior to posterior

LUQ – Starting point, coronal plane, lateral Transducer at left intercostal Left posterior axillary line Indicator toward patient’s head Angle probe anterior LUQ – Taping protocol Focus on kidney–spleen interface Sweep probe anterior to posterior Include view of diaphragm Include view of inferior kidney Include view of inferior tip of spleen

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 53

CHAPTER 3


Suprapubic – Starting point, sagittal plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s head Angle probe inferior Suprapubic – Taping protocol Focus on outline of bladder Sweep probe side to side Demonstrate retrovesicular space Demonstrate retrouterine space

–Alternative– Suprapubic – Starting point, transverse plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s right Angle probe inferior Suprapubic – Taping protocol Focus on outline of bladder Sweep probe superior to inferior Demonstrate retrovesicular space Demonstrate retrouterine space

53

A03750-Ch03.qxd

54

9/8/05

SECTION II

1:19 PM

Page 54


Optional Video Images Pericardial space – Starting point, parasternal long view Oblique plane, anterior Transducer at 5th intercostal space Lateral to sternum, left side Indicator toward patient’s right shoulder Probe perpendicular to chest wall Pericardial space – Parasternal long tape protocol Focus on outer silhouette of heart Slight sweep from left shoulder to right hip Only limited movement of probe is needed

Costophrenic angle right, starting point Coronal plane, lateral Transducer at costal margin Right middle axillary line Indicator toward patient’s head Angle probe toward patient’s head Costophrenic angle right – Tape protocol Focus on pleural space superior to diaphragm Sweep probe anterior to posterior Similar protocol to RUQ except orientation is superior

A03750-Ch03.qxd

9/8/05

1:19 PM

Page 55

CHAPTER 3


Costophrenic angle left Coronal plane, lateral Transducer at costal margin Left posterior axillary line Indicator toward patient’s head Angle probe toward patient’s head Costophrenic angle left – Tape protocol Focus on pleural space superior to diaphragm Sweep probe anterior to posterior Similar protocol to LUQ except orientation is superior

55

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 57

CHAPTER

Gallbladder Scanning Protocol

4

Romolo Gaspari

GOAL OF GALLBLADDER ULTRASOUND Demonstrate abnormalities in gallbladder and extrahepatic bile ducts including wall thickening, gallstones, ductal dilatations, and surrounding tissue. Emergency Ultrasound Approach Emergency medicine ultrasound of the gallbladder is focused on the clinical questions involving the gallbladder and common bile duct. Patients with right upper quadrant (RUQ) pain are commonly seen in the emergency department. The most common yes–no question that is addressed with an emergency medicine ultrasound of the gallbladder is whether or not there are gallstones. It is important to understand that the presence or absence of gallstones (or any other ultrasonic finding of the gallbladder) is not by itself diagnostic for biliary colic. Other questions such as evaluation of a palpable mass or the possibility of common bile duct dilation may also arise.

57

A03750-Ch04.qxd

58

9/8/05

SECTION II

1:20 PM

Page 58


Anatomy The anatomy of interest in the gallbladder scan involves the gallbladder and extrahepatic ductal system. The orientation of the gallbladder is variable as it is not completely tethered within the abdominal cavity. The anatomy of the extrahepatic ductal system has a number of common variations which are discussed below. Gallbladder Gallbladder interior Body Fundus Neck Wall of gallbladder Extrahepatic ductal system Common bile duct Hepatic duct Cystic duct Pericholecystic space Hepatic artery Common duct Portal vein

(Note: For the purpose of an emergency ultrasound any portion of the extrahepatic biliary duct is referred to as the “common duct.”) (To liver)

Neck

Body

Hepatic duct

Common bile duct

Cystic duct (To small bowel)

Patient Position Supine Sitting Left lateral decubitus Standing Patient Preparation A fasting state improves image quality. Transducer 3.0 to 5.0 MHz.

Fundus

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 59

CHAPTER 4


Gallbladder Pathology • Gallstones cause bright internal echoes with posterior shadowing that move with patient position • Sludge causes a dependent hypoechoic (but not anechoic) layer • Gallbladder wall thickening is defined as when the gallbladder wall measures more than 3 to 5 mm • Fluid around the gallbladder forms an anechoic rim or band • Gallbladder pathology, such as gallstones and sludge, is independently mobile of other gallbladder anatomy. Imaging of the gallbladder should be performed in multiple patient positions. Common Duct Pathology • The common duct normally measures less than 5 mm or 40% of associated portal vein but is larger in older individuals • Internal echoes within the lumen of the common duct may represent common duct stones Maneuvers Deep breaths (or pushing out abdominal wall) may lower the gallbladder below the costal margin.

Multiple locations for gallbladder

59

A03750-Ch04.qxd

60

9/8/05

SECTION II

1:20 PM

Page 60


Locating the Gallbladder • Multiple locations due to patient variation • Start at epigastrium and sweep along costal margin • Consider intercostal approach Locating the Common Duct • Locate portal triad in liver parenchyma • Locate neck of gallbladder • Image anterior to portal vein

Tricks of the Trade • Using a deep, wide initial sweep – Shows relative association between organs in the RUQ. • Deep breathing – Lowers the diaphragm causing the inferior edge of the liver to drop below the costal margin, improving image quality. • Patient positioning affects the location of the gallbladder – Sitting patient up, left lateral decubitus, standing. Changing patient position can improve image quality. • Gallbladder wall should be measured at anterior gallbladder due to increased artifact of posterior wall. • Gallbladder contracts following eating resulting in thickening of the gallbladder wall and decrease in gallbladder size.

ULTRASOUND IMAGES Gallbladder Essential Images • Gallbladder long axis • Gallbladder short axis • Neck of gallbladder • Body of gallbladder • Fundus of gallbladder Gallbladder Optional Images • Common duct long axis • Common duct short axis

GALLBLADDER LONG AXIS

Landmarks • Main lobar fissure • Portal triad

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 61

CHAPTER 4


Main Lobar Fissure Gallbladder

Portal vein

Kidney

Image Elements • Contour of gallbladder • Internal architecture of gallbladder • Pericholecystic space

Additional Information Obtained During Imaging • Gallbladder wall thickness • Common bile duct width

Tricks of the Trade • Drinking water prior to imaging gallbladder will decrease duodenal bowel gas and improve image quality. • Orientation of gallbladder is variable – Once it is located, oblique probe slightly back and forth to identify true long axis. • Gas–fluid interface of duodenum mimics gallbladder with gallstones. To tell the difference, (1) watch for peristalsis, (2) image gallbladder in at least two planes, and (3) look for another “gallbladder.”

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

61

A03750-Ch04.qxd

62

9/8/05

SECTION II

1:20 PM

Page 62


Too Cephalad Liver dominates view Gallbladder on right of screen Gallbladder fundus not seen

Gallbladder Portal vein IVC

Too Caudal Limited liver tissue in view (no landmarks) Gallbladder on left of screen (+/–) Small bowel dominates screen Poor image quality

Liver

Gallbladder

Bowel gas

Too Medial Liver dominates view No gallbladder in view

Duodenum Liver

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 63

CHAPTER 4


Too Lateral Liver–renal interface dominates view No gallbladder in view

Liver Bowel gas Kidney

Too Deep Gallbladder small and at top of image

Liver Gallbladder

Bowel gas

GALLBLADDER SHORT AXIS (NECK, BODY, AND FUNDUS VIEWS)

Landmarks • Superior pole of kidney

Liver

Gallbladder

Kidney

(Note: Superior pole of kidney is not always in same view as gallbladder.)

63

A03750-Ch04.qxd

64

9/8/05

SECTION II

1:20 PM

Page 64


Image Elements • • • •

Gallbladder contour Gallbladder wall Internal gallbladder architecture Pericholecystic space Tricks of the Trade • Clearly demonstrate landmarks in at least one view of transverse gallbladder. Some landmarks are not readily visualized in all transverse images of the gallbladder. • The transverse gallbladder is essentially an anechoic circle. Other anechoic circles seen in the RUQ can confuse the novice sonographer (portal vein, inferior vena cava, fluid-filled duodenum, etc.). Rotating the probe 90 degrees will differentiate the gallbladder from other vascular structures.

Neck of Gallbladder

Gallbladder

Liver

Portal vein

Body of Gallbladder

Gallbladder Liver

Kidney

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 65

CHAPTER 4


Fundus of Gallbladder

Liver

Bowel gas

Gallbladder

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Liver dominates image No gallbladder in view

Liver Hepatic veins IVC

Liver

Portal vein

65

A03750-Ch04.qxd

66

9/8/05

SECTION II

1:20 PM

Page 66


Too Caudad Bowel loops dominate image No gallbladder in view Poor image quality

Kidney

Bowel gas

Too Medial Liver dominates view Vena cava or aorta in view (+/–) Gallbladder on left of screen (+/–)

Liver Aorta IVC Spine

COMMON DUCT LONG AXIS Note: For the purposes of an emergency ultrasound of the extrahepatic ductal system, the term common duct refers to either the common bile duct or the hepatic duct.

Landmarks • Portal vein • Hepatic artery

Common bile duct Portal vein

Distal Common Duct

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 67

CHAPTER 4

Common duct


Gallbladder

Portal vein

Proximal Common Duct

Image Elements • Portal triad • Portal vein • Common duct • Hepatic artery • Images of common duct vary by location along course of common duct • Distal common duct • Portal vein and common duct run parallel to each other • Proximal common duct • Hepatic artery may course in between a parallel common duct and portal vein Tricks of the Trade • Imaging portal vein and common duct through liver parenchyma allows for higher image quality. • Identify the portal triad at the neck of the gallbladder in transverse orientation, rotate to long axis, and trace distally. • Doppler can distinguish hepatic artery from common duct. Partial View Probe Positioning All poor probe positioning will cause loss of visualization of common duct with either liver or small bowel dominating view.

67

A03750-Ch04.qxd

68

9/8/05

SECTION II

1:20 PM

Page 68


COMMON DUCT SHORT AXIS Landmarks • Portal triad • Neck of gallbladder • Main lobar fissure

Liver Common duct Portal vein

Gallbladder Hepatic artery IVC

Image Elements • Portal triad • Portal vein • Common duct • Hepatic artery Relationship of the components of the portal triad vary by location along course of portal vein. Tricks of the Trade • Locating the portal triad is more difficult than performing the actual protocol. • Lateral cystic shadowing may cause artifact that crosses the portal triad at the neck of the gallbladder. • Additional information can be obtained by imaging the distal common duct. After locating the common duct, trace it distally toward small bowel.

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 69

CHAPTER 4


Partial View Probe Positioning • All improper probe positioning will cause loss of visualization of common duct • Liver or small bowel dominates view Finding the Common Duct Main Lobar Fissure Gallbladder

Portal vein

Kidney

Using a long axis view of the gallbladder allows identification of the main lobar fissure which leads to the portal vein. Center probe on portal triad. Optimizing image quality and image layout will increase visualization of the common duct.

ULTRASOUND TECHNIQUE Still Image Protocol Gallbladder: Long Axis Approach – Sagittal or oblique plane, anterior Variable – Transducer at costal margin or intercostal Variable – Anterior midclavicular line Indicator toward patient’s head or right shoulder Probe perpendicular to skin

69

A03750-Ch04.qxd

70

9/8/05

SECTION II

1:20 PM

Page 70


–Alternative– Approach – Coronal plane, lateral Variable – Transducer at lower intercostals Midaxillary line Indicator toward patient’s head Probe perpendicular to skin

Gallbladder: Short Axis Approach – Transverse plane, anterior Variable – Transducer at costal margin or intercostal Variable – Anterior midclavicular line Indicator toward patient’s right side Probe perpendicular to skin

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 71

CHAPTER 4

Common Bile Duct or Hepatic Duct: Long Axis Approach – Oblique plane, anterior Transducer at left intercostals or subcostal Anterior midclavicular line Indicator toward patient’s head or right shoulder Probe perpendicular to skin


71

A03750-Ch04.qxd

72

9/8/05

SECTION II

1:20 PM

Page 72


Common Bile Duct or Hepatic Duct: Short Axis Approach – Oblique plane, anterior Transducer at left intercostals or subcostal Anterior midclavicular line Indicator toward patient’s head or left shoulder Probe perpendicular to skin

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 73

CHAPTER 4

VIDEOTAPE PROTOCOL Gallbladder: Long Axis Starting point – Oblique plane, anterior Transducer at left intercostals or subcostal Anterior midclavicular line Indicator toward patient’s head or right shoulder Probe perpendicular to skin Taping protocol Focus on longest axis of gallbladder Sweep medial to lateral and back Include entire length of gallbladder Sweep entire width of gallbladder

–Alternative– Starting point – Coronal plane, lateral Transducer at lower intercostals or costal margin Middle axillary line Indicator toward patient’s head Probe perpendicular to skin Taping protocol Focus on longest axis of gallbladder Sweep anterior to posterior and back Include entire length of gallbladder Sweep entire width of gallbladder


73

A03750-Ch04.qxd

74

9/8/05

SECTION II

1:20 PM

Page 74


Gallbladder: Short Axis Starting point – Transverse plane, anterior Variable – Transducer at costal margin or intercostal Variable – Anterior midclavicular line Indicator toward patient’s right side Probe perpendicular to skin Taping protocol Focus on gallbladder Sweep superior to inferior Include entire width of gallbladder Sweep entire length of gallbladder

A03750-Ch04.qxd

9/8/05

1:20 PM

Page 75

CHAPTER 4

Common Bile Duct or Hepatic Duct: Long Axis Starting point – Oblique plane, anterior Transducer at left intercostals or subcostal Midclavicular line Indicator toward patient’s right shoulder Probe perpendicular to skin Taping protocol Focus on parallel portal vein and common duct Measure diameter of common duct


75

A03750-Ch04.qxd

76

9/8/05

SECTION II

1:20 PM

Page 76


Common Bile Duct or Hepatic Duct: Short Axis Starting point – Oblique plane, anterior Transducer at left intercostals or subcostal Midclavicular line Indicator toward patient’s left shoulder Probe perpendicular to skin Taping protocol Focus on portal triad Portal vein Hepatic artery Common duct Measure diameter of common duct

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 77

CHAPTER

Renal Scanning Protocol

5

Romolo Gaspari

GOAL OF RENAL ULTRASOUND Demonstrate abnormalities in renal contour, echogenicity, size, internal architecture, and surrounding tissue.

EMERGENCY ULTRASOUND APPROACH Emergency medicine renal ultrasound is focused on the clinical questions involving the urinary tract system. Patients with hematuria or difficulty urinating are commonly seen in the emergency department. The most common yes–no questions addressed with an emergency medicine ultrasound of the renal system are those related to hydronephrosis, usually as a surrogate marker for a kidney stone. Other questions such as evaluation of a palpable mass or perinephric fluid also arise. Knowledge of the renal system is important because pathology in the kidney can confuse the novice sonographer when examining nearby organ systems. For example, a right renal cyst can easily be mistaken for the gallbladder, free fluid in Morison’s pouch, or the vena cava. Mastering renal ultrasound will solidify your ultrasound skills and carry over to other applications.

ANATOMY The anatomy of interest in the renal scan involves both kidneys and the bladder. Right kidney Kidney Renal cortex Renal medulla Renal pelvis Perirenal space Left kidney Kidney Renal cortex Renal medulla Renal pelvis Perirenal space Bladder Retrovesicular space 77

A03750-Ch05.qxd

78

9/8/05

SECTION II

1:21 PM

Page 78


PATIENT POSITION Supine Left lateral decubitus Right lateral decubitus

Extra-renal pelvis

Cortex Perirenal space

Medulla

PATIENT PREPARATION A full bladder assists in evaluation of the bladder.

TRANSDUCER 3.0 to 5.0 MHz

MANEUVERS Inserting a catheter and filling the bladder with fluid will assist in evaluating the bladder for some patients. RENAL PATHOLOGY • Hydronephrosis results in interconnecting anechoic spaces in the center of the kidney • Renal cysts result in round anechoic spaces in the parenchyma of the kidney • Renal stones in the body of the kidney result in bright echoes with posterior shadowing. (Note: Stones in the parenchyma of the kidney do not cause renal colic pain.)

ULTRASOUND IMAGES Renal Essential Images • Right kidney long axis • Right kidney short axis • Superior pole • Middle pole • Inferior pole Left kidney Bladder

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 79

CHAPTER 5


• Left kidney long axis • Left kidney short axis • Superior pole • Middle pole • Inferior Pole • Bladder • Long axis • Transverse axis

Right kidney

Bladder

Tricks of the Trade • If only one view of the kidney is possible, the long axis view including the renal collecting system provides the most clinical information. • When rotating the probe with the image of the kidney in the center of the ultrasound screen, the absolute longest length of the kidney is the true long axis.

RIGHT KIDNEY LONG AXIS Landmarks • Kidney silhouette

Renal cortex Renal medulla

Image Elements • Longitudinal view of right kidney • Renal pelvis • Renal medulla • Perinephric space

79

A03750-Ch05.qxd

80

9/8/05

SECTION II

1:21 PM

Page 80


Image Characteristics • Kidney contour • Kidney internal architecture • Cortex – medulla • Collecting system • Kidney echogenicity • Renal pelvis is the most echogenic structure of all abdominal organs • Renal cortex is slightly less echogenic than the adjacent liver parenchyma

Tricks of the Trade • When images are obscured by bowel gas, improvements in image quality may be seen by moving the probe posterior. • Echogenicity of the kidney can be altered with gain adjustments. To evaluate the kidney for hypo- or hyperechogenicity, compare it to the adjacent liver. • With true long axis of the kidney, slow rotation of the probe should shorten the length of the kidney. If it lengthens, then you know that you are slightly oblique. • The kidney is not tethered in the abdominal cavity. As the diaphragm contracts and relaxes during normal respirations, the kidney moves up and down. • Having the patient take a deep breath and hold it will allow improved windows for imaging the kidney.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Kidney on right of screen Incomplete view of kidney – lower pole missing

Liver

Kidney superior pole

Diaphragm

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 81

CHAPTER 5

Too Caudad Kidney on left of screen Incomplete view of kidney – superior pole missing

Liver

Kidney inferior pole

Too Medial No kidney seen Liver–bowel interface dominates image, or Gallbladder in view, or Vena cava in view, or Aorta in view

Gallbladder Portal vein IVC

Too Anterior Bowel loops dominate image, or Kidney small and deep in image

Duodenum Liver


81

A03750-Ch05.qxd

82

9/8/05

SECTION II

1:21 PM

Page 82


Oblique View Kidney with bulbous, asymmetric shape. Kidney migrates across screen with fanning through long axis. When moving from sagittal to parasagittal, the location of the kidney should not move on the ultrasound screen.

Kidney Liver

RIGHT KIDNEY SHORT AXIS Landmarks • Kidney silhouette • Gallbladder (+/–)

Liver

Image Elements • Kidney contour • Kidney internal architecture • Cortex • Medulla • Collecting system • Kidney echogenicity • Perinephric space

Kidney

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 83

CHAPTER 5

Images • Upper pole of right kidney

Liver

Kidney superior pole

• Middle pole of right kidney

Gallbladder

Liver

Renal vasculature

• Lower pole of right kidney

Kidney

Bowel


83

A03750-Ch05.qxd

84

9/8/05

1:21 PM

SECTION II

Page 84


Tricks of the Trade • If you are unsure that you have true transverse, find the true longitudinal view and rotate 90 degrees counterclockwise. • Imaging of the superior pole when it is just under the lowest rib can be accomplished by either moving intrathoracic and angling the probe caudad, or, moving subcostal and angling the probe cephalad. • Pathology of the kidney (tumors and cysts, etc.) may extend past the inferior or superior pole. To ensure visualization of the entire transverse kidney the kidney must disappear as the probe moves superior during imaging of the upper pole or inferior during imaging of the lower pole. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Liver dominates image No kidney in view

Gallbladder Liver

Too Caudad Bowel loops dominate image Poor image quality No kidney in view

Bowel

IVC

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 85

CHAPTER 5

Too Medial Kidney on left of screen, or Liver–bowel interface, or Vena cava in view, or Aorta in view

Kidney

Bowel gas

LEFT KIDNEY LONG AXIS Landmarks • Kidney silhouette

Spleen Perinephric space

Kidney Medulla Cortex

Image Elements • Kidney contour • Kidney internal architecture • Cortex • Medulla • Collecting system • Kidney echogenicity – Compare to splenic parenchyma • Perinephric space


85

A03750-Ch05.qxd

86

9/8/05

SECTION II

1:21 PM

Page 86


Tricks of the Trade • The left kidney is higher and more posterior than the right. • When rib shadows interfere with long axis imaging the left kidney, rotating the probe 5 degrees clockwise may improve imaging. • It is not always possible to view the entire long axis of the kidney. It is sometimes necessary to image the superior and inferior poles separately in the long axis. • Fluid in the stomach can sometimes form sharp angles due to interfacing with stomach contents and may be confused with perinephric fluid. • Air in the stomach degrades image quality when viewing the left kidney. To improve image quality either move the probe posterior, using the spleen as a window, or have the patient drink water to displace stomach air.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Kidney on right of screen Lower pole missing

Spleen Diaphragm Kidney Lung

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 87

CHAPTER 5

Too Caudad Kidney on left of screen Superior pole missing

Spleen Bowel gas Kidney

Too Medial or Anterior Poor image quality Stomach dominates view

Spleen Rib shadow Stomach

LEFT KIDNEY SHORT AXIS Landmarks • Kidney silhouette Image Elements • Kidney contour • Kidney internal architecture • Renal cortex • Renal medulla • Renal collecting system • Kidney echogenicity • Perinephric space


87

A03750-Ch05.qxd

88

9/8/05

SECTION II

1:21 PM

Page 88


Images • Upper pole of left kidney

Spleen Kidney

• Middle pole of left kidney

Kidney Renal vasculature Spleen

• Lower pole of left kidney

Kidney

Tricks of the Trade • Deep inspirations will lower the kidney and allow easier imaging of the superior pole. • Right lateral decubitus positioning allows better access for imaging in patients with “thoracic” kidneys.

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 89

CHAPTER 5


• A stomach with gas in it will degrade images while a stomach with fluid in it may improve images. Having the patient drink liquid may displace gas in stomach. • Pathology of the kidney (tumors and cysts, etc.) may extend past the inferior or superior pole. To ensure visualization of the entire transverse kidney the kidney must disappear as the probe moves superior during imaging of the upper pole or inferior during imaging of the lower pole.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad Spleen dominates view, or Lung dominates view, or No kidney in view

Rib shadow

Stomach

Too Caudad Bowel loops dominate view No kidney seen Poor images

Bowel

Spleen

89

A03750-Ch05.qxd

90

9/8/05

SECTION II

1:21 PM

Page 90


Too Medial or Too Anterior Poor image quality Stomach dominates view Kidney on right of image

Stomach Gas

Kidney

Bladder Bladder long axis Landmarks • Bladder silhouette • Bladder–uterine interface • Bladder–bowel interface

Bladder Vesico-uterine space Recto-uterine space Uterus

Image Elements • Bladder contour • Internal bladder architecture • Retrovesicular space

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 91

CHAPTER 5


Tricks of the Trade • Anterior/posterior orientation of the uterus in female patients will change depending on degree of bladder distention. • The most common error when the bladder is not visualized is that the probe is too superior. • An empty bladder or one with only a small amount of urine is difficult to visualize. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad or Angle Too Steep No bladder in image, or Bladder on right of screen, or Bowel dominates view

Vesico-uterine space

Bladder

Uterus Recto-uterine space

Too Caudad or Angle Too Shallow Pubic symphysis obscures view Poor image quality

Pubic symphysis Bowel

91

A03750-Ch05.qxd

92

9/8/05

SECTION II

1:21 PM

Page 92


BLADDER SHORT AXIS Landmarks • Bladder silhouette

Bladder

Image Elements • Bladder silhouette • Retrovesicular space • Internal bladder architecture

Tricks of the Trade • Imaging the retrovesicular space is easier with a full bladder. To fill the bladder you can have the patient drink fluids, or if there is a bladder catheter you can clamp the catheter. • It is uncomfortable to push on a full bladder. Limit the amount of pressure when imaging the bladder transabdominally.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Cephalad or Angle Too Steep No bladder in image Bowel dominates view Poor image quality Images will look similar if too caudad Too Caudad or Angle Too Shallow Pubic symphysis obscures view No view of bladder Poor image quality

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 93

CHAPTER 5


Too Lateral or Medial Bladder off center Full silhouette of bladder not seen

Bladder Uterus

ALTERNATIVE OR UNUSUAL VIEWS Rib Shadows When viewing either kidney it may be partially obscured by rib shadows. Moving the probe will effectively move the rib shadow so that all of the kidney may be visualized.

Spleen

Rib shadow Kidney

Obese Patients Patients with a large amount of intraperitoneal fat may have perirenal fat that separates the kidney from the liver.

Peri-nephric fat Kidney Liver

93

A03750-Ch05.qxd

94

9/8/05

SECTION II

1:21 PM

Page 94


Inferior Pole Obscured The duodenum on the left and the splenic flexure of the colon on the right may each obscure the inferior pole of the kidney.

Liver Duodenum Kidney

ULTRASOUND TECHNIQUE Still Image Protocol Right Kidney: Long Axis Approach – Sagittal plane, oblique posterior Transducer at lower intercostals or costal margin Right posterior axillary line Indicator toward patient’s head Angle probe slightly medial –Alternative– Approach – Sagittal plane, anterior Transducer at costal margin or lower intercostal Right anterior axillary line Indicator toward patient’s head Angle probe slightly medial

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 95

CHAPTER 5

–Alternative– Approach – Coronal plane, lateral Transducer at costal margin or lower intercostal Right middle axillary line Indicator toward patient’s head Angle probe slightly posterior


95

A03750-Ch05.qxd

96

9/8/05

SECTION II

1:21 PM

Page 96


Right Kidney: Short Axis Approach – Transverse plane, right lateral Transducer at costal margin or lower intercostal Right anterior, middle, or posterior axillary line Indicator toward patient’s back or right side Probe perpendicular to skin

Left Kidney: Long Axis Approach – Coronal plane, lateral Transducer at left intercostal Left posterior axillary line Indicator toward patient’s head Angle probe anterior

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 97

CHAPTER 5

Left Kidney: Short Axis Approach – Transverse plane, left lateral Transducer at left intercostal or subcostal Left posterior axillary line Indicator toward patient’s front Probe perpendicular to skin


97

A03750-Ch05.qxd

98

9/8/05

SECTION II

1:21 PM

Page 98


BLADDER Bladder: Long Axis Approach – Sagittal plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s head Angle probe inferior

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 99

CHAPTER 5

Bladder: Transverse Axis Approach – Transverse plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s right Angle probe inferior


99

A03750-Ch05.qxd

100

9/8/05

SECTION II

1:21 PM

Page 100


VIDEOTAPE PROTOCOL Right Kidney: Long Axis Starting point – Sagittal plane, lateral Transducer at lower intercostals or costal margin Right middle axillary line Indicator toward patient’s head Angle probe slightly posterior Taping protocol Focus on renal silhouette Sweep medial to lateral Include entire length of kidney Sweep entire width of kidney

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 101

CHAPTER 5

–Alternative– Starting point – Sagittal plane, anterior Transducer at lower intercostals or costal margin Right anterior axillary line Indicator toward patient’s head Angle probe slightly medial Taping protocol Focus on renal silhouette Sweep medial to lateral Include entire length of kidney Sweep entire width of kidney

–Alternative– Starting point – Coronal plane, lateral Transducer at costal margin or lower intercostal Right middle axillary line Indicator toward patient’s head Angle probe slightly posterior Taping protocol Focus on renal silhouette Sweep medial to lateral Include entire length of kidney Sweep entire width of kidney


101

A03750-Ch05.qxd

102

9/8/05

SECTION II

1:21 PM

Page 102


Right Kidney: Short Axis Starting point – Transverse plane, right lateral Transducer at lower intercostals or costal margin Right posterior, middle, or anterior axillary line Indicator toward patient’s right side or back Probe perpendicular to skin Taping protocol Focus on renal silhouette Sweep superior to inferior Include entire width of kidney Sweep entire length of kidney

Left Kidney: Long Axis Starting point – Coronal plane, lateral Transducer at left intercostal Left posterior axillary line Indicator toward patient’s head Angle probe anterior Taping protocol Focus on kidney silhouette Sweep probe anterior to posterior Include full length of kidney Sweep full width of kidney

A03750-Ch05.qxd

9/8/05

1:21 PM

Page 103

CHAPTER 5

Left Kidney: Short Axis Starting point – Transverse plane, left lateral Transducer at left intercostal Left posterior axillary line Indicator toward patient’s front Probe perpendicular to skin Taping protocol Focus on kidney silhouette Sweep probe superior to inferior Include full width of kidney Sweep full length of kidney

BLADDER Bladder: Long Axis Starting point – Sagittal plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s head Angle probe inferior Taping protocol Focus on outline of bladder Sweep probe side to side Demonstrate retrovesicular space


103

A03750-Ch05.qxd

104

9/8/05

SECTION II

1:21 PM

Page 104


–Alternative– Bladder: Transverse Starting point – Transverse plane, anterior Transducer at midline abdomen Superior to pubic symphysis Indicator toward patient’s right Angle probe inferior Suprapubic: Taping Protocol Focus on outline of bladder Sweep probe superior to inferior Demonstrate retrovesicular space

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 105

CHAPTER

6

Cardiac Scanning Protocol Paul Sierzenski

GOAL OF CARDIAC ULTRASOUND Demonstrate focused pathology in the heart or pericardium. Specifically: 1. Presence of cardiac activity 2. Identify or exclude a pericardial effusion or hemopericardium 3. Identify “impending tamponade” or “tamponade physiology” 4. Identify global cardiac hyperkinesias or hypokinesis 5. Measure the aortic root size

EMERGENCY ULTRASOUND APPROACH Emergency cardiac ultrasound by emergency physicians is focused on the clinical questions involving the heart or pericardium. Ultrasounds targeting potentially lifethreatening conditions are performed in a variety of clinical situations. A common yes–no question during a cardiac arrest is cardiac activity. Other situations include when patients have symptoms that could be caused by problems with the pericardium or heart. Patients with chest pain, shortness of breath, or hypotension are commonly seen in the emergency department.

ANATOMY The anatomy of interest in the cardiac scan involves the anatomy of the heart and pericardium. 1. Cardiac chambers Aorta • Left ventricle • Right ventricle • Left atrium Left atrium • Right atrium Right atrium 2. Pericardial space Mitral valve 3. Cardiac valves Aortic valve • Aortic valve • Mitral valve Tricuspid valve • Tricuspid valve

Right ventricle Left ventricle

105

A03750-Ch06.qxd

106

9/8/05

SECTION II

1:22 PM

Page 106


PATIENT POSITION Supine Left lateral decubitus Sitting

PATIENT PREPARATION Not applicable

TRANSDUCER • 2.0 to 5.0 MHz micro-convex or phased array • A smaller transducer “footprint” or area of contact with the skin allows better visualization of the heart through the ribs

MANEUVERS • Sitting up or left lateral decubitus will bring heart forward and improve image quality • Deep breaths will flatten diaphragm and may improve images in subxiphoid view

CARDIAC PATHOLOGY • Pericardial effusions result in an anechoic rim of fluid around the heart • Wall motion abnormalities result in restricted or no movement of areas of the heart (Note: A full discussion of the ultrasonographic findings in patients with focal wall motion abnormalities is beyond the scope of this book.) • Disease of the ascending aorta (i.e., aortic dissection) may result in widening of the aorta distal to the aortic valve (the aortic root) (Note: The cardiac ultrasound performed in the emergency department is a limited ultrasound that is designed to detect some of the emergent conditions seen in the emergency department. If any questions concerning pathology in the heart or pericardium are not adequately resolved, then a complete echocardiogram of the heart should be performed by a trained specialist.)

ULTRASOUND CARDIAC IMAGES • • • • •

Subxiphoid Parasternal long Parasternal short Apical two chamber Apical four chamber

Parasternal

Subxyphoid

Apical

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 107

CHAPTER 6

Cardiac Scanning Protocol

CARDIAC ESSENTIAL IMAGES There is no set of required images for emergency medicine cardiac ultrasound, as the ultrasound may be done for a variety of reasons. For example, during a cardiac arrest, any one view of the heart that demonstrates the absence of cardiac activity is sufficient. Other applications such as the evaluation of dyspnea require additional views. In general, most emergent cardiac pathology may be identified, verified, or excluded with a 4-chamber view (either subxiphoid or apical four chamber), a parasternal long axis view, and a parasternal short axis view. Any abnormality should be verified by more than one view or window. Tricks of the Trade • Small pericardial effusions and pericardial fat pads present as anechoic areas adjacent to the heart. The diameter of a pericardial effusion should change during systole and diastole. • More than one view is often required to confirm the presence of a pericardial effusion.

SUBXIPHOID Landmarks • Liver (when visualized) • Cardiac silhouette • Right ventricle (should be the most near-field chamber)

Liver Pericardial space Heart

Image Elements • Hepatic capsule/pericardial reflection • Right ventricle Tricks of the Trade • Stomach contents can degrade image quality when the ultrasound probe is in the epigastrium. Moving the probe to the anterior right costal margin will improve image quality.

107

A03750-Ch06.qxd

108

9/8/05

SECTION II

1:22 PM

Page 108


• Maximize the depth setting to include the entire heart on the ultrasound screen. • It may be difficult or even impossible to get a subxiphoid view in a patient with a distended abdomen as is commonly seen following the endotracheal intubation of a patient in cardiac arrest.

Partial View Probe Positioning Too Caudal, Too Steep of Angle, or Too Shallow Range of View Liver dominates view Heart at bottom of screen or not seen

Liver

Diaphragm

Too Lateral Right Liver dominates view Heart not seen

Liver

Portal vein

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 109

CHAPTER 6


Too Lateral Left Stomach gas artifact obscures view of heart No liver seen Poor image quality

Spleen Stomach

Parasternal long Landmarks • Cardiac silhouette • Aortic root • Descending thoracic aorta (DTA)

Left ventricle

Right ventricle Left atrium

Aortic valve Mitral valve Aorta

Image Elements (in One View) • Left ventricle • Left atrium • Aortic valve • Mitral valve • Right ventricle • Descending thoracic aorta Tricks of the Trade • Patients with chronic obstructive pulmonary disease (COPD) tend to have a cardiac axis that is more vertical than horizontal. They also have poor image quality due to increased air between the heart and sternum.

109

A03750-Ch06.qxd

110

9/8/05

SECTION II

1:22 PM

Page 110


Parasternal Short Axis (PSSAX) There are three common levels for imaging in the PSSAX (listed from proximal to distal): 1. At the level of the aortic valve 2. At the level of the mitral valve 3. At the level of the papillary muscles (classic middle left ventricle view) Landmarks • Cardiac silhouette • Papillary muscles • Aortic valve

Right ventricle Tricuspid valve Right arium Aortic valve Left atrium

PSS at level of aortic valve

Right ventricle

Mitral valve

PSSAX at mitral valve

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 111

CHAPTER 6


Left ventricle

Right ventricle

PSSAX at papillary muscle

Image Elements • Aortic valve • Aortic root • Left ventricle and surrounding pericardial space • Right ventricle (when seen) Tricks of the Trade • The easiest way to get a true PSSAX is to find the parasternal long axis and rotate the probe 90 degrees.

Apical Four Chamber Landmarks • Cardiac silhouette • Left ventricle • Right ventricle

Right ventricle

Left ventricle Mitral valve

Tricuspid valve Right atrium Left atrium

Image Elements • Left ventricle • Right ventricle • Left atrium • Right atrium

• Ventricular septum • Mitral valve • Tricuspid valve

111

A03750-Ch06.qxd

112

9/8/05

SECTION II

1:22 PM

Page 112


Tricks of the Trade • Locating the patient’s point of maximal impulse (PMI) will identify the placement of the probe for the apial 4 chamber or apial 2 chamber. Apical Two Chamber Landmarks • Cardiac silhouette • Left ventricle • Left atrium

Left ventricle

Left atrium

Image Elements • Left ventricle • Left atrium

ULTRASOUND TECHNIQUE Due to the inherent motion of the heart (when beating), videotape archiving of ultrasound images of the heart are easier to interpret. Much of the pathology of the heart is not apparent on still images. For example, with still images ultrasound pictures of a beating heart look identical to pictures of a heart in asystole. It is important to understand the machine pre-sets for cardiac imaging. When obtaining cardiac images the machine can be in the ‘cardiac’ pre-set mode or in another mode (such as ‘abdominal’ pre-set). The machine automatically flips the image during ‘cardiac’ imaging and will indicate this by showing the direction indicator to the right of the screen. You could functionally obtain the same images in the ‘abdominal’ settings if you were to flip the orientation of the ultrasound probe 180 degrees. All of the orientations provided in this text assume that you are imaging with the ultrasound machine in the ‘cardiac’ mode. Still Image Protocol • If still images of the cardiac exam are to be used they should include one for each image obtained [e.g., subxiphoid/subcostal view (SUBX), parasternal long axis (PSLAX), PSSAX, etc.] • Cardiac anatomic structures should be clearly identifiable

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 113

CHAPTER 6


• A systolic and a diastolic image should be obtained, especially if a pericardial effusion or focused pathology is identified • If a patient is in cardiac arrest, then at least three sequential, timed images should be obtained Video Image Protocol • If video images of the cardiac exam are to be used then each image listed below should be obtained (e.g., SUBX, PSLAX, PSSAX, etc.) • Cardiac anatomic structures should be clearly identifiable • All cardiac videotape protocols involve little to no actual movement of the probe once the image is perfected • Any probe movements are for the purpose of clearing up a specific section of the ultrasound image or including an area of the heart that is not on the screen • For each image obtained a number of sequential cardiac cycles should be included (systole and diastole) Cardiac: Subxiphoid/Subcostal View (SUBX) Approach – Coronal, oblique inferior Transducer under anterior ribs Epigastrium or right subcostal Transducer indicator toward patient’s left side Probe angled toward left shoulder or head

113

A03750-Ch06.qxd

114

9/8/05

SECTION II

1:22 PM

Page 114


Cardiac: Parasternal Long Axis (PSLAX) Approach – Oblique plane, anterior Transducer left parasternal, intercostal Indicator toward patient’s right shoulder or head Probe perpendicular to skin

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 115

CHAPTER 6

Cardiac: Parasternal Short Axis (PSSAX) Approach – Oblique plane, anterior Transducer left parasternal, intercostal Indicator toward patient’s left shoulder or left side 90 degrees clockwise rotation from the PSLAX Probe perpendicular to skin Move probe superior–inferior (moves from aortic root to mid-ventricle)


115

A03750-Ch06.qxd

116

9/8/05

SECTION II

1:22 PM

Page 116


Cardiac: Apical Four Chamber (A4C) Approach – Coronal plane, anterior oblique Transducer subcostal or low intercostals Left mid-clavicular line Indicator toward patient’s right side Angle probe toward left hip (indicator to left axilla)

Cardiac: Apical Two Chamber (A2C) Approach – Sagittal plane, anterior oblique Transducer subcostal or low intercostal Left mid-clavicular line Indicator toward ceiling Angle probe toward left hip (point toward right shoulder)

A03750-Ch06.qxd

9/8/05

1:22 PM

Page 117

CHAPTER 6

Optional Views Suprasternal notch – Long (or short axis) View of aortic arch Approach – Coronal superior (or sagittal) Transducer above clavicular heads Indicator toward head (or left side) Angle probe inferior


117

A03750-Ch06.qxd

118

9/8/05

SECTION II

1:22 PM

Page 118


Subxiphoid short axis (note, this is a two-chamber view) Approach – Sagittal plane, anterior Transducer under anterior ribs Epigastrium or right subcostal Indicator toward patient’s head or ceiling Probe angled toward right shoulder or head

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 121

CHAPTER

7

First Trimester Scanning Protocol J. Christian Fox

GOAL OF A FIRST TRIMESTER ULTRASOUND Demonstrate abnormalities in first trimester pregnancy focusing on abnormal intrauterine pregnancies or ectopic pregnancies. Recognize normal ovarian structures to differentiate these from abnormal adnexal masses.

EMERGENCY ULTRASOUND APPROACH Emergency medicine ultrasound during the first trimester is focused on the clinical questions involving the growing embryo. Patients with bleeding during the first trimester are commonly seen in the emergency department. The most common yes–no questions addressed for these patients are those pertaining to ectopic pregnancy. The approach to imaging the uterus during the first trimester can be transabdominal or endovaginal.

ANATOMY The anatomy of interest in the first trimester ultrasound involves the uterus. In the upright female the pelvis is tilted at 45 degrees. The uterus has a variable orientation as it is tethered at only one end. The ultrasound will focus on the contents of the uterus and the surrounding tissues. Uterus Fundus Body Body Cervix Endometrial cavity Ovary Fundus Bladder Retro-vesicular Endometrial space Retrovesicular space cavity

Cervix

121

A03750-Ch07.qxd

122

9/8/05

SECTION III

1:23 PM

Page 122

Pelvic Protocols

Uterine Fundus

Ovary Uterine Body Endometrial Cavity

Fallopian Tube Cervix

Vagina

Empty bladder

Full Bladder

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 123

CHAPTER 7

First Trimester Scanning Protocol

PATIENT POSITION • Supine • Thighs abducted (endovaginal) Elevating the pelvis off of the stretcher or bringing the patient inferiorly, as in a speculum evaluation, allows a full range of movement of the endovaginal probe. Inadequate patient positioning can result in poor image quality.

PATIENT PREPARATION Transabdominal – Full bladder improves imaging of uterus Endovaginal – Empty bladder improves imaging of uterus

TRANSDUCER Transabdominal – 3.0 to 5.0 MHz Endovaginal – 5 to 7.5 MHz

UTERINE PATHOLOGY • Uterine fibroids can result in a thickened uterine wall or discrete masses within the uterine wall • Fluid collections in the endometrial cavity can be a result of pregnancy but the appearance varies depending on condition (ectopic vs. normal pregnancy) and age of gestation • A small amount of fluid in the rectouterine space (posterior cul-de-sac) is normal • Fluid in the vesicouterine pouch (anterior cul-de-sac) is almost never normal and should arouse suspicion of a pathologic condition

OVARIAN PATHOLOGY • Masses within the ovary can represent neoplastic activity (Note: Ovarian neoplasms vary in ultrasonographic appearance and a full description is beyond the scope of this book.) • Cysts within the ovary can represent normal follicular rupture, hemorrhagic cysts, or simple cysts • Complex fluid collections in the adnexa can represent infection or ectopic pregnancy

Tricks of the Trade • Occasionally the ovaries are located more anterior. In this case it may not be possible to visualize them using the endovaginal approach without causing marked discomfort. Better images may be obtained from a transabdominal approach. • There is an added dimension when performing an endovaginal ultrasound. Inserting or removing the endovaginal probe may be needed to visualize all structures.

123

A03750-Ch07.qxd

124

9/8/05

1:23 PM

SECTION III

Page 124

Pelvic Protocols

• While a full bladder is recommended for locating the pelvic structures in a transabdominal technique, this is not necessarily required. In the majority of cases the answer can be achieved by looking first, prior to filling the bladder. • In the transabdominal approach, applying firm pressure with the transducer will displace tissue and bowel resulting in a decreased effective focal point. This ultimately results in improved image quality but may cause discomfort in a patient with a full bladder. • In patients with pelvic pathology (ovarian cysts and peri-appendiceal abscesses, etc.), the normal anatomic structures become even more important in order to maintain one’s landmarks. If confused about possible pathology, return to the original landmarks described in this textbook to obtain your “bearings” and reorient yourself.

FIRST TRIMESTER ESSENTIAL IMAGES • Uterus long axis • Transabdominal • Endovaginal • Uterus short axis • Transabdominal • Endovaginal • Adnexa left and right

Abdominal

Endovaginal

UTERUS LONG AXIS: TRANSABDOMINAL Landmarks • Bladder • Uterine outline • Endometrial stripe/cavity

Bladder Uterus Endometrial stripe Vaginal stripe

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 125

CHAPTER 7


Bladder Uterus Endometrial space

Image Elements • Contour of uterus • Endometrial cavity of uterus • Bladder • Vaginal stripe

Tricks of the Trade • Contour and orientation of the uterus are extremely variable from woman to woman and change with volume of urine in the bladder. • It is helpful to train your eye to search for and identify the long axis view of the uterus to use as a “home base” when imaging the pelvis. • Probe orientation can be posterior, anterior, left or right due to the orientation of the uterus. • Filling the bladder results in increased transabdominal views of the uterus and ovaries.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Superior Bladder on right of screen (if seen) Limited view of uterus

Uterus Endometrial cavity

125

A03750-Ch07.qxd

126

9/8/05

1:23 PM

SECTION III

Page 126

Pelvic Protocols

Too Inferior Uterine fundus not in view Vaginal stripe centered in view

Bladder Uterus Vagina

Cervix

Too Lateral Uterus off-midline Endometrial cavity not in view

Bladder

Uterus

UTERUS LONG AXIS: ENDOVAGINAL Landmarks • Bladder • Uterine outline • Endometrial stripe/cavity

Bladder Uterus Endometrial cavity

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 127

CHAPTER 7


Image Elements • Contour of uterus • Endometrial cavity of uterus • Bladder Tricks of the Trade • Emptying the bladder results in improved endovaginal imaging quality. • It may be necessary to slightly “twist” or rotate the endovaginal probe along its axis in order to observe the entire endometrial stripe. • It may be necessary to pivot the probe side to side to fully visualize the long axis of the uterus. • In women who have a very sharply anteverted uterus, you may need to pivot the probe so the transducer surface is aimed toward the ceiling. • In women with retroverted uteruses or very full bladders, it may be necessary to pivot the probe so the indicator is toward the floor (aim the transducer surface posteriorly). • The vesicouterine space is occasionally difficult to image in the sagittal endovaginal route when the bladder is empty. • It may be necessary to slightly withdraw the probe 1 to 2 centimeters in order to visualize an empty bladder.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Posterior Uterus on left of screen Cervix dominates view

Cervix Uterus

127

A03750-Ch07.qxd

128

9/8/05

SECTION III

1:23 PM

Page 128

Pelvic Protocols

Too Anterior Bladder dominates view Uterus on right

Bladder Uterus

Too Inferior (Probe Not Inserted Enough) Bladder in view (size depends on volume of urine in bladder) No or limited uterus seen Poor image quality

Bladder

Uterus

Too Lateral Uterus off-midline Endometrial cavity not in view

Uterus

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 129

CHAPTER 7


UTERUS SHORT AXIS: TRANSABDOMINAL Landmarks • Bladder • Uterine outline • Endometrial cavity

Bladder

Uterus Endometrial cavity

Images • Contour of uterus • Endometrial cavity of uterus • Retrovesicular space Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Superior No bladder or uterus seen, or Uterus seen but no endometrial cavity seen

Bowel loops

Bowel gas

129

A03750-Ch07.qxd

130

9/8/05

SECTION III

1:23 PM

Page 130

Pelvic Protocols

Too Inferior Pubic symphysis obscures view, or View of lower uterine segment or cervix

Bladder Lower uterine segment

Too Lateral Uterus off-midline

Uterus

Iliac vessels

Bladder

Tricks of the Trade • Filling the bladder with a Foley catheter or oral hydration will increase image quality during transabdominal imaging. • It may be necessary to fan very inferiorly in some women who have small uteruses, retroverted uteruses, or larger diameter abdomens. • In the transverse view, the endometrial “stripe” now appears as the echogenic oval structure at the center of the uterine body.

UTERUS SHORT AXIS: ENDOVAGINAL Landmarks • Bladder • Uterine outline • Endometrial cavity

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 131

CHAPTER 7


Bladder Retro-vesicular space Uterus Endometrial cavity

Image Elements • Contour of uterus • Endometrial cavity of uterus • Retrovesicular space Tricks of the Trade • The endovaginal coronal plane provides information on the contour of the uterus and may identify pathology not seen on longitudinal plane such as a duplicated or bicornuate uterus. • It may be necessary to slightly remove the probe 1 to 2 centimeters in order to obtain a view of the retrovesicular space. • Emptying the bladder will improve image quality during endovaginal imaging. • Higher imaging quality is obtained with endovaginal imaging than transabdominal imaging.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Posterior No view of endometrial cavity Lower uterine segment or cervix dominates view

Lower uterine segment

131

A03750-Ch07.qxd

132

9/8/05

SECTION III

1:23 PM

Page 132

Pelvic Protocols

Too Anterior Bladder dominates view No uterus seen

Bladder

Uterus (fundus)

Too Inferior (Probe Not Inserted Far Enough) Bladder dominates view No uterus seen

Bladder

Too Lateral Uterus off-midline

Uterus

Bowel loops

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 133

CHAPTER 7


Too Shallow Incomplete view of uterus and endometrial cavity

Bladder Uterus Endometrial cavity

ADNEXA (RIGHT AND LEFT) (Note: An additional discussion on imaging the adnexa is contained in Chapter 8 on imaging the ovaries.) Ovaries and surrounding area may sometimes be seen by transabdominal ultrasound but endovaginal ultrasound is usually required. Bladder Ovary Iliac vessels

Landmarks • Iliac artery and vein • Uterus Image Elements • Ovarian silhouette • Internal ovarian architecture • Para-ovarian space Tricks of the Trade • Finding the ovaries can be an art. Locating them in either sagittal or coronal planes is adequate. Finding the iliac vessel often provides a landmark for locating the ovary. Once the iliac is located, look anterior and medial to locate the ovary.

133

A03750-Ch07.qxd

134

9/8/05

SECTION III

1:23 PM

Page 134

Pelvic Protocols

• In a transabdominal window, the center of the uterus is the endometrial stripe, or “face of koala bear.” To each side of the uterus are the ovaries, or “ears of the koala bear.” • Venous plexus in the adnexa can sometimes look similar to an ovary on gray-scale imaging but will show marked differences with Doppler imaging. • A normal female will have some small follicular cysts on her ovaries.

UNUSUAL OR ATYPICAL VIEWS Transabdominal: Uterus On Top of Bladder • A common normal variant • Anteroverted and anteroflexed uterus • Bladder not completely filled

Uterus Endometrial stripe Bladder

ULTRASOUND TECHNIQUE Still Image Protocol Uterus: Long Axis Transabdominal Approach – Sagittal anterior Transducer infraumbilical, suprapubic Mid-abdominal line Indicator toward patient’s head Probe angled toward feet

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 135

CHAPTER 7


Uterus: Long Axis Endovaginal Approach – Sagittal inferior Transducer intravaginal Mid-abdominal line Indicator toward ceiling Horizontal probe angle is variable, depending on lie of uterus Probe handle moved side to side until stripe appears

135

A03750-Ch07.qxd

136

9/8/05

SECTION III

1:23 PM

Page 136

Pelvic Protocols

Uterus: Short Axis Transabdominal Approach – Transverse anterior Transducer infraumbilical, suprapubic Mid-abdominal line Indicator toward patient’s right side Probe angled toward feet

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 137

CHAPTER 7


Uterus: Short Axis Endovaginal Approach – Coronal inferior Transducer intravaginal Mid-abdominal line Indicator toward patient’s right leg Probe handle lifted toward ceiling or pushed down toward floor

Adnexa: Endovaginal Approach – Sagittal inferior Transducer intravaginal Indicator toward ceiling Obtain initial view of long axis uterus Angle probe laterally (+/–) Pivot probe handle toward patient’s opposite leg Focus on long axis view of iliac vessel Focus on ovary silhouette (medial and anterior to iliacs) Repeat for opposite side

137

A03750-Ch07.qxd

138

9/8/05

SECTION III

1:23 PM

Page 138

Pelvic Protocols

VIDEOTAPE PROTOCOL Uterus: Long Axis Transabdominal Starting point – Sagittal anterior Transducer infraumbilical, suprapubic Mid-abdominal line Indicator toward patient’s head Probe angled toward feet Taping protocol Focus on longest length of uterus Sweep right to left and back Include entire length of uterus on screen Sweep entire width of uterus Focus on uterine cavity Sweep entire width of uterine cavity

Uterus: Long Axis Endovaginal Starting point – Sagittal inferior Transducer intravaginal Orient along mid-abdominal line Indicator toward ceiling Horizontal orientation variable, slight angle down or horizontal Taping protocol Focus on longest axis of uterus Sweep left to right and back Include entire length of uterus on screen Sweep entire width of uterus Focus on endometrial cavity Sweep entire width of cavity

A03750-Ch07.qxd

9/8/05

1:23 PM

Page 139

CHAPTER 7

Uterus: Transabdominal Short Axis Starting point – Transverse anterior Transducer infraumbilical, suprapubic Mid-abdominal line Indicator toward patient’s right side Probe angled toward feet Taping protocol Focus on outline of uterus Sweep superior to inferior and back Include entire width of uterus on screen Sweep entire length of uterus Focus on uterine cavity Sweep entire length of uterine cavity

Uterus: Endovaginal Short Axis Starting point – Transverse inferior Transducer endovaginal Mid-abdominal line Indicator toward ceiling Probe angled toward floor Taping protocol Focus on outline of uterus Sweep anterior to posterior and back Include entire width of uterus on screen Sweep entire length of uterus Focus on uterine cavity Sweep entire length of uterine cavity


139

A03750-Ch07.qxd

140

9/8/05

SECTION III

1:23 PM

Page 140

Pelvic Protocols

Adnexa: Endovaginal Starting point – Sagittal inferior Transducer endovaginal Indicator toward ceiling Obtain initial view of long axis uterus Angle probe laterally (+/–) Pivot probe handle toward patient’s opposite leg Focus on long axis view of iliac vessel Focus on ovary silhouette (medial and anterior to iliacs) Repeat for opposite side Taping protocol Focus on outline of ovary Sweep probe medial–lateral or obliquely anterior superior (perpendicular to probe indicator) Scan through area around ovary

A03750-Ch08.qxd

9/8/05

1:23 PM

Page 141

CHAPTER

Ovarian Scanning Protocol

8

J. Christian Fox

GOAL OF AN OVARIAN ULTRASOUND Demonstrate abnormalities in the ovary focusing on abnormal ovarian architecture (cysts, masses) or blood flow to ovary.

EMERGENCY ULTRASOUND APPROACH Emergency medicine ultrasound of the ovary is focused on the clinical questions involving possible abnormalities of the ovary. Patients with pelvic pain are commonly seen in the emergency department. The most common yes–no questions addressed for these patients are those pertaining to ovarian cysts (i.e., ruptured, hemorrhagic). The most serious yes–no question involving the ovary is the question of ovarian torsion. There are two diagnostic approaches for patients with a concern of ovarian torsion. One is to look for alternative diagnoses that will explain the patient’s symptoms; the other is to look for ovarian torsion directly. In either case additional imaging is required if the emergency ultrasound does not provide a conclusive diagnosis. Directly imaging the ovary and paraovarian space may provide all of the information that is needed for a diagnosis. Doppler imaging may demonstrate decreased blood flow consistent with ovarian torsion. Indirect information on ovarian pathology can be gathered by demonstrating fluid in the dependent portion of the pelvis (i.e., pouch of Douglas or retrovesicular pouch). Doppler ultrasound can provide useful information during the evaluation of the ovary. It is used to evaluate blood flow to the ovaries. However, Doppler ultrasound is an advanced technique that can be difficult to master. Some physicians may not feel comfortable mastering Doppler imaging. Conditions such as ovarian torsion may intermittently demonstrate normal blood flow and decreased blood flow may be seen in a normal ovary. A complete discussion of Doppler ultrasound is beyond the scope of this book. As with all emergency ultrasound protocols, gray-scale imaging is critical prior to beginning any Doppler assessment.

141

A03750-Ch08.qxd

142

9/8/05

SECTION III

1:23 PM

Page 142

Pelvic Protocols

ANATOMY The anatomy of interest involves the ovary and surrounding tissues. The ovary has a somewhat variable location within the female pelvis. The ovaries are found anterior and medial to the iliac vessels and measure 2 × 2 × 3 centimeters. Ovary Left Right Uterus Iliac artery Iliac vein Retrovesicular space Pouch of Douglas

Ovary Fallopian tube Uterine body Iliac vessels

PATIENT POSITION Supine Thighs abducted

PATIENT PREPARATION • Endovaginal – Empty bladder improves imaging of uterus and ovaries • Transabdominal – Full bladder improves images of uterus but usually has no effect on imaging ovaries

TRANSDUCER Endovaginal – 5 to 7.5 MHz Transabdominal – 3 to 5 MHz

OVARIAN PATHOLOGY • Masses within the ovary can represent neoplastic activity (Note: Ovarian neoplasms vary in ultrasonographic appearance and a full description is beyond the scope of this book.) • Ovarian cysts (anechoic structures) within the ovary can represent normal follicular rupture, hemorrhagic cysts, or simple cysts • Complex fluid collections in the adnexa can represent infection or ectopic pregnancy • Free fluid in the pelvis may be a nonspecific sign of pathology in the pelvis

A03750-Ch08.qxd

9/8/05

1:23 PM

Page 143

CHAPTER 8

Ovarian Scanning Protcol

OVARY ESSENTIAL IMAGES • Right ovary • Sagittal view • Coronal view • Doppler images • Left ovary • Sagittal view • Coronal view • Doppler images • Inferior pelvic recess • Pouch of Douglas • Retrovesicular pouch

Tricks of the Trade • In women who are multiparous, the ovaries have a more variable location. Occasionally they are located more anterior. Attempting to visualize anterior ovaries using the endovaginal probe can cause discomfort or not be possible at all. Therefore it may be necessary to use the transabdominal approach in these women. • It is common for the novice sonographer to mistake bowel for ovary. Recall that bowel regularly demonstrates peristalsis and readily slides when pressure is applied with the probe. • A normal female will have some small follicular cysts on her ovaries. • Set the initial color/power Doppler gain, filter, pulse repetition frequency (PRF), and scale low enough so you can identify slow velocities within the ovary.

ENDOVAGINAL OVARY Note: In normal patient anatomy, left and right ovarian images are nearly identical. Landmarks, image elements, and poor probe positions are unchanged. Labeling as left or right ovary is crucial for later interpretation.

143

A03750-Ch08.qxd

144

9/8/05

SECTION III

1:23 PM

Page 144

Pelvic Protocols

Ovary: Endovaginal, Sagittal Landmarks • Iliac vessels • Ovarian follicles Bladder Ovary Iliac vessels

(Note: Doppler imaging is not needed to find the ovary in most patients.) Image Elements • Ovary • Paraovarian space Image Characteristics • Ovary contour • Ovary internal architecture • Small internal cysts • Ovary with color and spectral Doppler (both venous and arterial)

Ovarian Venous Waveform

Ovarian Arterial Waveform

A03750-Ch08.qxd

9/8/05

1:23 PM

Page 145

CHAPTER 8


Tricks of the Trade • Finding the ovary can be an art. Imaging the adnexa in a sagittal plane will result in a long axis view of the iliac vessels. The ovary should lie just medial and anterior to the iliac vessels. • It may be necessary to gently insert the endovaginal probe further in order to visualize the ovaries. • Pelvic structures such as the ovary, fallopian tube, and bowel should all slide easily among one another when pressure is applied with the probe. This “sliding organ sign” helps to rule out pathology. • Elevating the pelvis off the stretcher as in a speculum examination allows for a full range of movement of the endovaginal probe. • Endovaginal imaging of the ovaries is superior to transabdominal imaging. • Pelvic vessels can mimic the appearance of an ovary with follicular cysts. The short axis of these vessels may appear as cysts (round, anechoic) but the vessels will elongate with probe rotation. Doppler can also be used to differentiate uterine vasculature from ovarian follicles.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Medial Uterus dominates view No view of ovary

Uterus Iliac vein

145

A03750-Ch08.qxd

146

9/8/05

SECTION III

1:23 PM

Page 146

Pelvic Protocols

Too Anterior, Posterior, or Lateral Bowel or soft tissue dominates view No view of ovary

OVARY: ENDOVAGINAL CORONAL Landmarks • Uterus (+/–) • Ovarian follicles

Ovary

Uterus

Ovary

Image Elements • Ovary • Paraovarian space Image Characteristics • Ovary contour • Ovary internal architecture • Small internal cysts

A03750-Ch08.qxd

9/8/05

1:23 PM

Page 147

CHAPTER 8


Tricks of the Trade • Doppler imaging does not need to be obtained in more than one plane. • When attempting to locate the ovaries it is easy to get “lost.” Re-center probe on coronal view of uterus and advance laterally to adnexa or find ovary in sagittal axis and rotate 90 degrees.

Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Medial Uterus dominates view No view of ovary Too Anterior, Posterior, or Lateral Bowel dominates view No view of ovary

OVARY: TRANSABDOMINAL Imaging the ovaries using a transabdominal approach is difficult. Superior views are achieved using an endovaginal approach.

Bladder Retrovesicular space Uterus Endometrial cavity

147

A03750-Ch08.qxd

148

9/8/05

SECTION III

1:24 PM

Page 148

Pelvic Protocols

OVARY: TRANSABDOMINAL, SAGITTAL Landmarks • Ovarian silhouette

Bladder Ovary

Image Elements • Ovary • Bladder Image Characteristics • Ovarian contour • Ovarian internal architecture Tricks of the Trade • A full bladder will greatly improve image quality. • If unable to visualize the ovary transabdominally, drain the bladder and image the ovary endovaginally. • Doppler imaging of the ovary is better performed during endovaginal ultrasound.

Partial View Probe Positioning Most partial views of the ovary are images where the ovary is not centered in the screen. Atypical probe positions during a transabdominal ultrasound of the ovary will result in no visualization of the ovary.

OVARY: TRANSABDOMINAL, TRANSVERSE Landmarks • Uterine body • (+/–) Iliac vessels

A03750-Ch08.qxd

9/8/05

1:24 PM

Page 149

CHAPTER 8


Bladder Gas Ovary Uterus

Image Elements • Ovary contour • Ovary internal architecture • Ovary with Doppler Tricks of the Trade • Applying firm pressure with the transducer will displace tissue and bowel resulting in improved image quality but may cause the patient some discomfort if the bladder is full. • In a transabdominal window, the center of the uterus is the endometrial stripe, or “face of koala bear.” To each side of the uterus are the ovaries, or “ears of the koala bear.” Partial View Probe Positioning Many partial views of the ovary are images where the ovary is not centered in the screen. Atypical probe positions during a transabdominal ultrasound of the ovary will result in no visualization of the ovary. Too Superior or Inferior No view of ovary Uterus in view

Uterus Bladder

Too Lateral Bowel dominates view No view of ovary

Iliac vessels

149

A03750-Ch08.qxd

150

9/8/05

1:24 PM

SECTION III

Page 150

Pelvic Protocols

PELVIC CUL-DE-SACS Landmarks • Bladder • Uterus

Bladder Anterior cul-de-sac Uterus Posterior cul-de-sac

Image Elements • Contour of uterus • Contour of bladder • Anterior cul-de-sac, or, rectouterine space • Posterior cul-de-sac, or, vesicouterine space, or, pouch of Douglas Tricks of the Trade • A small amount of fluid in the rectouterine space (posterior cul-de-sac) is normal. • Fluid in the vesicouterine pouch (anterior cul-de-sac) is almost never normal and should arouse suspicion of a pathologic condition.

Partial View Probe Positioning Too Lateral Bladder small or not seen Limited view of recesses

Uterus

A03750-Ch08.qxd

9/8/05

1:24 PM

Page 151

CHAPTER 8

Too Inferior Poor image quality, or Bladder dominates view No view of pouch of Douglas

Bladder Uterus

Too Anterior Bladder dominates view Uterus on right of image Limited view of posterior cul-de-sac Anterior cul-de-sac Bladder

Uterus

Too Posterior Uterus dominates view Limited or no view of anterior cul-de-sac Cervix Uterus Posterior cul-de-sac


151

A03750-Ch08.qxd

152

9/8/05

SECTION III

1:24 PM

Page 152

Pelvic Protocols

ULTRASOUND TECHNIQUE Still Image Protocol Left Ovary: Sagittal Approach – Sagittal, inferior Transducer – Endovaginal Orient probe toward left shoulder Indicator toward ceiling Probe parallel to stretcher

Right Ovary: Sagittal Approach – Sagittal, inferior Transducer – Endovaginal Orient probe toward right shoulder Indicator toward ceiling Probe parallel to stretcher

A03750-Ch08.qxd

9/8/05

1:24 PM

Page 153

CHAPTER 8

Left Ovary: Coronal Approach – Coronal, inferior Transducer – Endovaginal Orient probe toward left shoulder Indicator toward patient’s right Probe parallel to stretcher


153

A03750-Ch08.qxd

154

9/8/05

SECTION III

1:24 PM

Page 154

Pelvic Protocols

Right Ovary: Coronal Approach – Coronal, inferior Transducer – Endovaginal Orient probe toward right shoulder Indicator toward patient’s left Probe parallel to stretcher

Pelvic Recess (Anterior and Posterior Cul-de-sac) Approach – Sagittal, inferior Transducer – Endovaginal Mid-abdominal line Indicator toward ceiling Probe oriented slightly toward floor

A03750-Ch08.qxd

9/8/05

1:24 PM

Page 155

CHAPTER 8

VIDEOTAPE PROTOCOL Ovary: Left Starting point – Sagittal, inferior Transducer – Endovaginal Orient probe toward left shoulder Indicator toward ceiling Probe parallel to stretcher Taping protocol Focus on long axis of ovary Sweep right to left and back Focus on area around ovary Sweep left to right and back Rotate probe 90 degrees counterclockwise Move handle up and down


155

A03750-Ch08.qxd

156

9/8/05

SECTION III

1:24 PM

Page 156

Pelvic Protocols

Ovary: Right Starting point – Sagittal, inferior Transducer – Endovaginal Orient probe toward right shoulder Indicator toward ceiling Probe parallel to stretcher Taping protocol Focus on long axis of ovary Sweep right to left and back Focus on area around ovary Sweep left to right and back Rotate probe 90 degrees clockwise Move handle up and down

Pelvic Recess (Anterior and Posterior Cul-de-Sac) Starting point – Sagittal, inferior Transducer – Endovaginal Mid-abdominal line Indicator toward ceiling Probe oriented slightly toward floor Taping protocol Focus on outline of uterus Sweep left to right and back

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 159

CHAPTER

Aorta Scanning Protocol

9

Romolo Gaspari

GOAL OF AORTA ULTRASOUND Demonstrate abnormalities in abdominal aorta primarily related to size.

EMERGENCY ULTRASOUND APPROACH Emergency ultrasound of the aorta is focused on the clinical questions involving the abdominal aorta. Patients with back pain, abdominal pain, or flank pain are commonly seen in the emergency department. The most common yes–no questions addressed with an emergency medicine ultrasound of the abdominal aorta are those pertaining to aneurysmal dilatation of the aorta.

ANATOMY The anatomy of interest in the aorta scan involves the abdominal aorta and the area around the aorta. Aorta Upper aorta Middle aorta Lower aorta

159

A03750-Ch09.qxd

160

9/8/05

SECTION IV

1:24 PM

Page 160

Vascular Protocols

Prevertebral space Celiac artery Hepatic artery Splenic artery Left gastric artery Superior mesenteric artery (SMA) Iliac arteries Inferior vena cava Splenic vein Left renal vein

Hepatic artery Celiac artery Portal vein

Splenic artery

IVC Renal veins

Splenic vein SMA SMV

Aorta

Iliac veins

Iliac arteries

The aorta follows the natural curvature of the spine in its course through the abdomen, lying immediately anterior and slightly left of the spine. The prevertebral space is the area between the shadow of the lumbar spine and the aorta. The upper aorta consists of the portion containing the first two sonographically identified arteries: the celiac artery and the SMA. The middle aorta consists of the portion of the aorta with no sonographically recognizable branches. The inferior aorta consists of the portion where the aorta bifurcates into the iliac arteries just under the umbilicus. The inferior vena cava runs roughly parallel to the aorta, along the right side of the spine.

Celiac artery Superior mesenteric artery Pre-vertebral space

Iliac arteries Spine Upper aorta Middle aorta

Lower aorta

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 161

CHAPTER 9


The celiac artery (or celiac trunk) is the first major branch of the abdominal aorta and runs perpendicular to the aorta. This is a short vessel that quickly branches into the splenic and hepatic arteries (which are commonly seen) and the left gastric artery (which is not). In a transverse window, the celiac, hepatic, and splenic arteries form the shape of a mustache, seagull, or the letter T. The body of the seagull is the celiac artery with the right and left wings formed by the hepatic and splenic arteries. The second branch of the abdominal aorta, the SMA, courses parallel to the aorta inferiorly. In a short axis the SMA appears as a “mantle clock” or a white triangle with a dark circular center due to the hyperechoic fat and muscle surrounding the vessel as it exits the aorta.

PATIENT POSITION Supine


TRANSDUCER 2.5 to 5.0 MHz curved or phased array probe

AORTA PATHOLOGY • Aortic dissection and atherosclerosis result in intraluminal echoes • Aortic aneurysms result in dilatation of aorta • Leaking aortic aneurysms rarely show free abdominal fluid

ULTRASOUND IMAGES Aorta Essential Images • Aorta long axis • Superior aorta • Middle aorta • Inferior aorta • Aorta short or transverse axis • Superior aorta • Middle aorta • Inferior aorta

Upper aorta

Lower aorta

Umbilicus

161

A03750-Ch09.qxd

162

9/8/05

1:24 PM

SECTION IV

Page 162

Vascular Protocols

Tricks of the Trade • Gentle persistent pressure helps displace bowel loops to improve visualization of the abdominal aorta. • Occasionally firm pressure is necessary in larger patients, or those with large amounts of bowel gas.

AORTA LONGITUDINAL, SUPERIOR Landmarks • Spinal shadow • Celiac artery • SMA

Liver Superior mesenteric Celiac trunk Aorta

Image Elements • Aorta contour • Aorta internal architecture Tricks of the Trade • Superior views of the aorta can be easily distinguished from the superior vena cava by looking for the celiac or superior mesenteric arteries. • Bowel gas from the stomach that is obscuring your view may be decreased by turning the patient onto the right lateral decubitus to pool fluid in the stomach into the antrum. • Longer length of time spent performing ultrasound of the abdomen will increase the amount of bowel activity and bowel gas, thereby decreasing image quality. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 163

CHAPTER 9

Too Superior Liver and cardiac structures dominate view Images are short axis, subxiphoid views No aorta in view

Liver

Heart

Too Caudal Aorta in view No celiac artery or SMA Images are mid-aorta or lower aorta views

Aorta Spine

Too Lateral Right Inferior vena cava (IVC) dominates view

Liver

Portal vein

IVC


163

A03750-Ch09.qxd

164

9/8/05

SECTION IV

1:24 PM

Page 164

Vascular Protocols

Too Lateral Left Bowel loops dominate view, or Stomach dominates view Poor image quality

Bowel loop

Aorta longitudinal, middle Landmarks • Spinal shadow • Liver (+/–)

Aorta Spine

Image Elements • Aorta contour • Aorta internal architecture

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 165

CHAPTER 9


Tricks of the Trade • Slow, steady pressure on the ultrasound probe will displace bowel loops and increase image quality. • The aorta follows the lumbar lordosis and courses from “deep to shallow,” while the IVC has a more level course in the abdomen. • An ectatic aorta may follow an abnormal path in the abdomen; if you lose the aorta, go back to where you initially saw it (long or transverse). Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Superior Celiac artery and SMA in view View is of superior aorta

Liver Superior mesenteric artery Celiac trunk Aorta

Too Caudal Iliac artery in view Looks very similar to middle aorta in longitudinal plane (but probe is inferior to umbilicus)

Aorta

165

A03750-Ch09.qxd

166

9/8/05

SECTION IV

1:24 PM

Page 166

Vascular Protocols

Too Lateral Left Bowel loops dominate view May see lower edge of spleen May see left kidney

Bowel

Kidney

Too Lateral Right IVC in view Looks similar to middle aorta

IVC

Tricks of the Trade • If you are unsure the vascular structure is vena cava or aorta, scan laterally and medially to identify other vascular structures, or • Return to superior aorta, identify celiac or superior mesenteric artery and trace inferiorly, or • Rotate probe to transverse view and identify spinal shadow, or • Use Doppler signal to identify arterial waveform.

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 167

CHAPTER 9


AORTA LONGITUDINAL, LOW Landmarks • Spinal shadow

Aorta

Image Elements • Aorta contour • Aorta internal architecture Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Superior Middle aorta in view Looks almost identical to lower aorta

Aorta Spine

167

A03750-Ch09.qxd

168

9/8/05

SECTION IV

1:24 PM

Page 168

Vascular Protocols

Too Caudal Iliac vessel in view, or Bowel loops dominate view Poor image quality

Bowel

Too Lateral Right IVC in view

IVC

Too Lateral Left Bowel loops dominate view Poor image quality

Bowel loop

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 169

CHAPTER 9


Tricks of the Trade • When sliding probe inferiorly in long axis, differentiating distal aorta from proximal iliac is difficult to determine from long axis ultrasound images. • If image of aorta is lost in bowel gas while sliding inferiorly, return to previously identified segment and retrace inferiorly. • A quick transverse view will demonstrate the iliac bifurcation in cases where the long axis view is not definitive.

AORTA TRANSVERSE, SUPERIOR Landmarks • Spinal shadow • Celiac artery • SMA

Celiac artery IVC

Aorta Spine

Superior mesenteric artery IVC

Aorta Spine

Image Elements • Aorta contour • Aorta internal architecture Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

169

A03750-Ch09.qxd

170

9/8/05

SECTION IV

1:24 PM

Page 170

Vascular Protocols

Too Caudal Aorta in view No celiac artery or superior mesenteric artery Image is view of middle aorta

Aorta Spine

IVC

Too Lateral Right Aorta off center IVC centered in view

Liver Aorta IVC Spine

Too Lateral Left Aorta off center Bowel loops dominate view Stomach gas obscured aorta

Liver Stomach IVC Spine

Aorta

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 171

CHAPTER 9


AORTA TRANSVERSE, MIDDLE Landmarks • Spinal shadow

Aorta IVC

Spine

Images • Aorta contour • Aorta internal architecture Tricks of the Trade • Anterior–posterior measurement of the aorta for dilatation can be artificially increased if the ultrasound probe is held perpendicular to the abdominal wall due to the lumbar lordosis of the aorta. The ultrasound probe should be angled 5 to 10 degrees cephalad for more accurate measurements. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan. Too Superior Celiac artery in view, or SMA in view View is of superior aorta

Celiac artery IVC

Aorta Spine

171

A03750-Ch09.qxd

172

9/8/05

SECTION IV

1:24 PM

Page 172

Vascular Protocols

Too Caudal View is of distal aorta or iliacs

Iliac arteries IVC Spine

Too Lateral Right Aorta off center IVC centered in view

Bowel gas

IVC Aorta

Too Lateral Left Aorta off center Bowel loops dominate view

Kidney Aorta Spine

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 173

CHAPTER 9


AORTA TRANSVERSE, LOW Landmarks • Spinal shadow • Iliac bifurcation

IVC

Aorta Spine

Bowel gas Iliac bifurcation Spine

Image Elements • Aorta contour • Aorta internal architecture Tricks of the Trade • Avoid imaging aorta or iliac bifurcation directly over umbilicus as air is commonly trapped there and can degrade the image quality. • Include views of iliac bifurcation in lower aorta views as pathology may sometimes be only seen at iliac/aorta junction. • Inferior aorta is closest to abdominal wall (and ultrasound probe) due to lumbar lordosis. Partial View Probe Positioning Note: Many of the partial views contain information that is needed to accurately identify pathology. The ideal view may be unobtainable due to patient characteristics and multiple “partial views” will be required to complete the scan.

173

A03750-Ch09.qxd

174

9/8/05

SECTION IV

1:24 PM

Page 174

Vascular Protocols

Too Superior Middle aorta in view

Aorta IVC

Spine

Too Caudal Distal iliacs in view, or Bowel loops dominate view Usually image quality is degraded

Iliac arteries IVC Spine

Too Lateral Right Proximal iliacs or aorta off center to right IVC centered in view, or Bowel loops dominate view

Iliac arteries IVC

Spine

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 175

CHAPTER 9

Too Lateral Left Proximal iliacs off center to left, or Bowel loops dominate view Iliac arteries

Bowel gas Spine

Alternative Views Coronal view of aorta and vena cava Liver IVC Aorta

IVC centered in view, mistaken for aorta Lack of spinal shadow

Liver

Portal vein

IVC


175

A03750-Ch09.qxd

176

9/8/05

SECTION IV

1:24 PM

Page 176

Vascular Protocols

AORTA VS. VENA CAVA Mistaking the vena cava for the aorta is a common error of novice ultrasonographers. Some aspects of the images that differentiate one from the other are as follows: Aorta Vena Cava Pulsations Single strong pulsation Double wavy pulsation Course in abdomen “Deep to shallow” Parallel to abdominal wall Vessels seen on ultrasound SMA and celiac None Transverse silhouette Round Variable Location to spine Directly anterior Right lateral Changes with inspiration None Increase diameter

ULTRASOUND TECHNIQUE Still Image Protocol Aorta: Long Axis, Superior Approach – Sagittal plane, anterior Transducer at subxiphoid Epigastrium Indicator toward patient’s head Probe perpendicular to skin

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 177

CHAPTER 9

Aorta: Long Axis, Mid Approach – Sagittal plane, anterior Transducer halfway from epigastrium to umbilicus Mid-abdominal line Indicator toward patient’s head Probe perpendicular to skin or angled toward head


177

A03750-Ch09.qxd

178

9/8/05

SECTION IV

1:24 PM

Page 178

Vascular Protocols

Aorta: Long Axis, Low Approach – Sagittal plane, anterior Transducer halfway from epigastrium to umbilicus Mid-abdominal line Indicator toward patient’s head Probe perpendicular to skin or angled toward head

Aorta: Transverse or Short Axis, Superior Approach – Transverse plane, anterior Transducer at subxiphoid Epigastrium Indicator toward patient’s right side Angle probe slightly toward head

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 179

CHAPTER 9

Aorta: Short or Transverse Axis, Mid Approach – Transverse plane, anterior Transducer halfway from epigastrium to umbilicus Mid-abdominal line Indicator toward patient’s right side Angle probe slightly toward head


179

A03750-Ch09.qxd

180

9/8/05

SECTION IV

1:24 PM

Page 180

Vascular Protocols

Aorta: Short or Transverse Axis, Low Approach – Transverse plane, anterior Transducer periumbilical Mid-abdominal line Indicator toward patient’s right side Angle probe slightly toward head

OPTIONAL VIEWS Aorta: Long Axis, Coronal Approach – Coronal plane, lateral Transducer at costal margin Mid-axillary line Indicator toward patient’s head Probe perpendicular to skin

A03750-Ch09.qxd

9/8/05

1:24 PM

Page 181

CHAPTER 9

VIDEOTAPE PROTOCOL Aorta: Long Axis Starting point – Sagittal plane, anterior Transducer at epigastrium Mid-abdominal line (line from subxiphoid to umbilicus) Indicator toward patient’s head Probe perpendicular to skin Taping protocol Focus on area anterior to spine Sweep superior to inferior Follow course of aorta Include entire length of aorta


181

A03750-Ch09.qxd

182

9/8/05

SECTION IV

1:24 PM

Page 182

Vascular Protocols

–Alternative– Starting point – Coronal plane, transverse Transducer at costal margin Right middle axillary line Indicator toward patient’s head Probe perpendicular to skin Taping protocol Focus on aorta silhouette Sweep superior to inferior Follow course of aorta Sweep entire length of aorta

Aorta: Short Axis Starting point – Transverse plane, anterior Transducer at epigastrium Mid-abdominal line (line from subxiphoid to umbilicus) Indicator toward patient’s right side Probe perpendicular to skin or angled slightly toward head Taping protocol Focus on area anterior to spine Sweep superior to inferior Follow course of aorta Sweep entire length of aorta

A03750-Ch10.qxd

9/8/05

1:25 PM

Page 183

CHAPTER

Lower Extremity Vascular Scanning Protocol

10

J. Christian Fox

GOAL OF LOWER EXTREMITY VASCULAR ULTRASOUND Demonstrate abnormalities in the veins of the leg primarily related to obstruction of venous flow.

EMERGENCY ULTRASOUND APPROACH Emergency medicine lower extremity vascular ultrasound is focused on the clinical questions involving pain and swelling in the legs. The most common yes–no questions addressed with an emergency medicine ultrasound of the lower extremity are those related to the presence of deep vein thrombosis (DVT).

ANATOMY The anatomy of interest in the lower extremity vascular ultrasound involves the common femoral vein and the popliteal vein. Common femoral vein Saphenous vein Inguinal region Common femoral artery Popliteal vein Popliteal artery

Medial thigh Popliteal fossa

183

A03750-Ch10.qxd

184

9/8/05

SECTION IV

1:25 PM

Page 184

Vascular Protocols

Femoral artery

Common femoral

Profunda femoris Popliteal artery

Popliteal

Great saphonous

The lower extremity blood vessels enter at the inguinal crease and course around the medial thigh as they descend. Superiorly, the vein lies deep to the artery but this reverses behind the knee (popliteal fossa) with the artery deeper.

PATIENT POSITION Common Femoral Vein • Supine • Leg in external rotation Popliteal Vein • Supine • Leg flexed at knee • Leg in external rotation, or • Leg dangling over edge of examination table, or • Prone position • Leg flexed at knee


TRANSDUCER 5.0 to 7.5 MHz Linear or wide footprint, curved ultrasound probe

LOWER EXTREMITY VASCULAR PATHOLOGY • Inability to fully compress venous structures and decreased Doppler signal with calf augmentation (when compared to contralateral side) correspond to DVT

A03750-Ch10.qxd

9/8/05

1:25 PM

Page 185

CHAPTER 10


MANEUVERS • Slightly bending the leg with external rotation allows easier access to the popliteal fossa • Squeezing the lower extremity with one hand while imaging proximally with Doppler will detect augmented venous flow in a normal patient • Arterial (pulsatile) and venous (phasic) Doppler wave forms are easily differentiated

Arterial Tracing

Venous Tracing

LOWER EXTREMITY VASCULAR ESSENTIAL IMAGES • Superior vasculature (transverse) • Common femoral vein and artery • Start at level of great saphenous vein • Gray-scale image • Image with compression • Lower vasculature (transverse) • Popliteal vein and artery • Gray-scale image • Image with compression Additional Images • Common femoral vein and artery • Doppler • Doppler with augmentation • Popliteal vein and artery • Doppler • Doppler with augmentation

Probe Placement

185

A03750-Ch10.qxd

186

9/8/05

SECTION IV

1:25 PM

Page 186

Vascular Protocols

Each set of essential images (gray scale, compression) is repeated every 2 cm from the inguinal crease to the superior calf. Tricks of the Trade • Repeated external calf compressions can exhaust the venous reservoir and result in loss of flow pulse during augmentation. • Deep veins are always paired but superficial vessels may be single. • Keeping part of the hand holding the ultrasound probe in contact with the patient’s skin will prevent inadvertent migration of the probe head during image acquisition. • The primary criterion proven most useful in the diagnosis of DVT is grayscale compression. Employing Doppler techniques such as augmentation only serves as an adjunct to the diagnosis, and should not be solely relied upon.

COMMON FEMORAL ARTERY AND VEIN Landmarks • Vein and artery outline • Doppler signal (if needed)

Saphenous vein Common femoral vein

Common femoral artery

A03750-Ch10.qxd

9/8/05

1:25 PM

Page 187

CHAPTER 10

CFV gray scale


CFV with augmentation

CFV with compression

Artery Vein Artery Vein

Without compression

With compression

Image Elements • Artery contour • Vein contour • Vein internal architecture • Compression of vessel • Doppler signal (+/– augmentation)

Tricks of the Trade • Using increased pressure when initially attempting to locate the common femoral vein may collapse it and limit visualization. Use gentle pressure when locating the veins as they compress easily. • Older clots may adhere to the vessel wall, allowing flow proximally. Differentiation of chronic vs. acute clots requires advanced techniques beyond the scope of this textbook. • Failure to use sufficient pressure to compress a vein may result in a false positive. Use enough pressure to cause slight dimpling of the skin. The artery is compressed when too much pressure is applied.

187

A03750-Ch10.qxd

188

9/8/05

SECTION IV

1:25 PM

Page 188

Vascular Protocols

Too Much Initial Probe Pressure Visualization of arteries and not veins Same image as with intentional compression

Common femoral artery

Compressed vein

Popliteal vein and artery Landmarks • Vein and artery outline • Doppler signal

Popliteal vein Popliteal artery

Image Elements • Artery contour • Vein contour • Vein internal architecture • Compression of vessel • Doppler signal (+/– augmentation)

A03750-Ch10.qxd

9/8/05

1:25 PM

Page 189

CHAPTER 10


Tricks of the Trade • It may be helpful to remember the rhyme: “The Vein Comes to the Top in the Pop”, when deciding which vessel is venous in the popliteal fossa. • In the popliteal fossa, the biceps femoris tendon may interfere with compression resulting in a false-positive ultrasound for intraluminal clot in the popliteal vein.

ULTRASOUND TECHNIQUE Still Image Protocol Common Femoral Vein and Artery: Short Axis Approach – Transverse plane, anterior Transducer at inguinal crease Indicator toward patient’s right side Probe perpendicular to skin Light pressure

189

A03750-Ch10.qxd

190

9/8/05

SECTION IV

1:25 PM

Page 190

Vascular Protocols

Images Required at Each Point of Common Femoral Vein Paired images every 2 cm: Gray-scale static image Gray-scale image with compression of venous structures Additional Images Color flow Doppler image Color flow Doppler image with venous augmentation Compress calf or thigh while imaging (Note: The probe does not move during the two essential and two additional images.) Popliteal Vein and Artery: Short Axis Approach – Transverse plane, posterior Transducer at popliteal fossa Indicator toward patient’s right side Probe perpendicular to skin Light pressure

Images Required at Each Point of Popliteal Vein Paired images every 2 cm: Gray-scale static image Gray-scale image with compression of venous structures

A03750-Ch10.qxd

9/8/05

1:25 PM

Page 191

CHAPTER 10


Optional Images Color flow Doppler image Color flow Doppler image with venous augmentation Compress calf while imaging (Note: The probe does not move during the two essential and two additional images.)

VIDEOTAPE PROTOCOL Common Femoral Vein and Artery: Short Axis Starting point – Transverse plane, anterior Transducer superior to inguinal crease Indicator toward patient’s right side Probe perpendicular to skin Light pressure Taping protocol Focus on silhouette of vein and artery Slide inferior toward knee Follow course of common femoral vein Compress vein in 2-cm increments Stop every 2 cm to repeat image sequence Continue until popliteal vein (see below)

191

A03750-Ch10.qxd

192

9/8/05

SECTION IV

1:25 PM

Page 192

Vascular Protocols

Popliteal Vein and Artery: Short Axis Starting point – Transverse plane, anterior Transducer at popliteal fossa, as superior as possible Indicator toward patient’s right side Probe perpendicular to skin Light pressure Taping protocol Focus on silhouette of vein and artery Slide inferior toward ankle Follow course of popliteal vein Compress vein in 2-cm increments Stop every 2 cm to repeat image sequence Continue into calf until vein is not visualized

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 195

CHAPTER

Testicle Scanning Protocol

11

Paul Sierzenski

GOAL OF TESTICLE ULTRASOUND Demonstrate abnormalities in the testicle and scrotum related to internal architecture, echogenicity, testicular contour, and blood flow. Additionally, fluid collections, cysts, and masses can be identified.

EMERGENCY ULTRASOUND APPROACH Emergency medicine ultrasound of the testicle is focused on the clinical questions involving the scrotum and testicle. Patients with acute scrotal pain or testicular swelling are commonly seen in the emergency department. The most common yes–no question to be addressed for these patients is the presence or absence of testicular torsion. A detailed understanding of all aspects of Doppler ultrasound is critical to the effective use of testicular ultrasound in emergency medicine. However, a complete discussion of Doppler ultrasound is beyond the scope of this book. Doppler imaging is a more complex application that many physicians may not feel comfortable attempting to master. As with all emergency ultrasound protocols a series of gray-scale images is critical prior to beginning any Doppler assessment. There are two general ways that emergency ultrasound can be used in the workup of scrotal pain. Ultrasound can either “rule out” testicular torsion or diagnose an alternative, more common diagnosis such as epididymitis. In the first scenario ultrasound demonstrates equal arterial and venous flow within the symptomatic and asymptomatic testicles. In the second scenario ultrasound confirms the presence of findings that effectively exclude torsion, such as epididymitis/orchitis. Many physicians who use testicular ultrasound use it in a limited capacity, specifically to include and support the diagnosis of epididymitis with or without orchitis, rather than the inclusion or exclusion of testicular torsion due to medical legal risks. In most cases immediate urological consultation should be considered unless it is clear that outpatient follow-up is appropriate.

195

A03750-Ch11.qxd

196

9/8/05

SECTION V

1:26 PM

Page 196

Small Parts Protocols

ANATOMY The anatomy of interest involves the testicle; its blood supply and the surrounding tissues. Testicle • Testicular artery • Epididymis Head • Head • Body Body Epididymus • Tail • Testicle Tail • Mediastinum testis • Scrotal dermis

Posterior-lateral view

Artery

Epididymis Testicle

Scrotal skin

Epididymis

PATIENT POSITION • Supine, with legs straight or in frog-leg position for comfort • It is important to remember that patients presenting with testicular or scrotal pain may be reluctant to move

PATIENT PREPARATION • Use several towels or drapes to isolate the scrotum, and have the patient’s penis rest on the abdomen

TRANSDUCER • 7.5 to 10 MHz linear probe

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 197

CHAPTER 11


TESTICULAR PATHOLOGY • Epididymitis results in relatively hypoechoic images of the epididymis • Orchitis results in relatively hypoechoic images of the testicle • Testicular torsion results in varied images depending on time to presentation

TESTIS ESSENTIAL IMAGES • Right testicle • Testicle long axis • Testicle short axis • Epididymis • Head • Body • Tail • Left testicle • Testicle long axis • Testicle short axis • Epididymis • Head • Body • Tail • Bilateral testes – Transverse view

Compare testis color or power Doppler with sample box crossing regions of both testes simultaneously.

Tricks of the Trade • Analgesia prior to imaging may improve image quality since any movement may result in flash artifacts for both color and spectral Doppler. • A lower frequency probe (3.5–5.0 MHz) may be used in patients with a greatly enlarged scrotum but a higher frequency probe should be attempted first. • Always image the asymptomatic testicle first. • Stabilize the testicle with your non-scanning hand. Often doing this from below the testis with a towel is helpful as the testis can slide after gel is applied. • Set the initial color/power Doppler gain, filter, PRF, and scale low enough so you can identify slow velocities within the testicle. Adjust these to eliminate overgained Doppler, flash artifacts, and phantom flow.

197

A03750-Ch11.qxd

198

9/8/05

SECTION V

1:26 PM

Page 198


TESTICLE: LONG AXIS Views of the long axis of the testes comprise superior and inferior views to include all aspects of the testicle and epididymis. Lateral or medial views of the long axis of the testicle are included to see the portion of the testes not images by a single long axis view.

TESTICLE: LONG AXIS, MIDDLE Landmarks • Testicular silhouette

Testicle

Image Elements • Epididymis (head) • Testicle • Mediastinum testis • Scrotal skin Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) • Testicle with color and spectral Doppler (both venous and arterial)

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 199

CHAPTER 11


Doppler Images

Arterial Tracing

Venous Tracing

Tricks of the Trade • All poor sagittal probe positions will result in the testis appearing smaller than actual size. • Too lateral or too medial can result in identification of peripheral flow rather than central flow on color or spectral ultrasound. In chronic, intermittent, or late-presenting testicular torsion there can be increased peripheral testis flow but decreased central testis blood flow. • Too superior or inferior transverse probe positions can result in identification of peripheral blood flow rather than central testis blood flow on color or spectral Doppler.

TESTICLE: LONG AXIS, SUPERIOR, OR EPIDIDYMIS HEAD, SAGITTAL Landmarks • Testicular silhouette • Epididymis

Epididymus Testicle

199

A03750-Ch11.qxd

200

9/8/05

1:26 PM

SECTION V

Page 200


Image Elements • Epididymis (head) • Testicle • Mediastinum testis (+/–) Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) • Epididymis internal architecture

TESTICLE: LONG AXIS, LATERAL OR MEDIAL Landmarks • Testicular silhouette (Note: Silhouette is similar to long axis but testicle appears smaller. The farther off axis the smaller the testicle will appear.)

Mediastinum testes

Image Elements • Testicle • Mediastinum testis (+/–) Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) • Epididymis internal architecture

TESTICLE: LONG AXIS, INFERIOR Landmarks • Testicular silhouette • Epididymis

Testicle

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 201

CHAPTER 11


Inferior testicle Epididymus

Image Elements • Epididymis (tail) • Testicle Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) • Epididymis internal architecture Partial View Probe Positioning The only partial view probe positionings of the testes demonstrate images where the probe extends off of the surface of the scrotum.

TESTICLE: SHORT AXIS, MIDDLE Landmarks • Testicular silhouette

Testicle

Image Elements • Epididymis (head) • Testicle • Mediastinum testis

201

A03750-Ch11.qxd

202

9/8/05

SECTION V

1:26 PM

Page 202


Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver or thyroid) • Testicle with color and spectral Doppler (both venous and arterial) Doppler Images

Arterial Tracing

Venous Tracing

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 203

CHAPTER 11


Tricks of the Trade • Too lateral or too medial can result in identification of peripheral flow rather than central flow on color or spectral ultrasound. In chronic, intermittent, or late-presenting testicular torsion there can be increased peripheral testis flow but decreased central testis blood flow. • Too superior or inferior transverse probe positions can result in identification of peripheral blood flow rather than central testis blood flow on color or spectral Doppler. • Probe orientation for a transverse plane of testicle is variable as testicular lie may vary as a result of torsion, mass effect, or swelling.

TESTICLE: SHORT AXIS, SUPERIOR Landmarks • Testicular silhouette

Epididymus Testicle

Image Elements • Epididymis (+/–) • Testicle • Mediastinum testis (+/–) Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver or thyroid)

203

A03750-Ch11.qxd

204

9/8/05

SECTION V

1:26 PM

Page 204


TESTICLE: SHORT AXIS, INFERIOR Landmarks • Testicular silhouette

Epididymus Testicle

Image Elements • Epididymis (+/–) • Testicle • Mediastinum testis (+/–) Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) Partial View Probe Positioning The only partial view probe positionings of the testes demonstrate images where the probe extends off of the surface of the scrotum.

Probe off skin

Testicle

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 205

CHAPTER 11

BILATERAL TESTICLE: SHORT AXIS Landmarks • Double testicle silhouette

Testicle Median raphe

Image Elements • Right testicle • Left testicle • Median raphe Image Characteristics • Testicle contour • Testicle internal architecture • Homogenous (similar to liver) Partial View Probe Positioning Too Lateral One testicle larger than the other

Testicle


205

A03750-Ch11.qxd

206

9/8/05

SECTION V

1:26 PM

Page 206


Tricks of the Trade • A direct comparison of testicular tissue characteristics can be helpful in diagnosing testicular pathology. • Be careful of image orientation to accurately identify the appropriate testicle. • Clearly label right or left testicle to prevent confusion during later review.

ULTRASOUND TECHNIQUE Still Image Protocol Testicle: Long Axis, Sagittal Approach – Sagittal plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s head Midline of testicle Probe perpendicular to skin

Medial

Lateral

Include single or multiple images of medial and lateral testicle to completely image the testicle.

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 207

CHAPTER 11

Testicle: Long Axis, Medial, Parasagittal Approach – Sagittal plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s head Medial portion of testicle Probe perpendicular to skin Testicle: Long Axis, Lateral, Parasagittal Approach – Sagittal plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s head Lateral portion of testicle Probe perpendicular to skin Testicle: Short Axis, Superior Approach – Transverse plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s right Superior testicle Probe perpendicular to skin

Testicle: Short Axis, Middle Approach – Transverse plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s right Middle of testicle Probe perpendicular to skin


207

A03750-Ch11.qxd

208

9/8/05

SECTION V

1:26 PM

Page 208


Testicle: Short Axis, Inferior Approach – Transverse plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s right Inferior testicle Probe perpendicular to skin

Bilateral Testicle: Short Axis Approach – Transverse plane, anterior Transducer on anterior surface of scrotum Probe over middle of scrotum Indicator toward patient’s right Probe perpendicular to skin

Single Testicle: Doppler Images Long or short axis Same approach as with gray scale Find intratesticular tissue with representative blood flow Color or power Doppler imaging Spectral imaging Bilateral Testicle: Doppler Images Short axis Same approach as with gray scale Find intratesticular tissue with representative blood flow Color or power Doppler imaging Spectral imaging

A03750-Ch11.qxd

9/8/05

1:26 PM

Page 209

CHAPTER 11


Testicle: Long Axis, Coronal or Sagittal Approach – Coronal (or sagittal) plane, inferior Transducer on inferior surface of scrotum Indicator toward patient’s right (or ceiling) Probe perpendicular to skin, parallel to stretcher (Note: This view may aid in Doppler signal identification as blood flow to the testis begins superior to inferior along the course of the testicular and deferential arteries.)

VIDEOTAPE PROTOCOL Testicle: Long Axis Starting point – Sagittal plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s head Midline of testicle Probe perpendicular to skin Taping protocol Focus on silhouette of testicle Sweep medial to lateral Scan entire width of testicle Include entire length of testicle Hold long axis view of testicle Color Doppler and spectral Doppler images

209

A03750-Ch11.qxd

210

9/8/05

SECTION V

1:26 PM

Page 210


Testicle: Short Axis Starting point – Transverse plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s right side Midline of testicle Probe perpendicular to skin Taping protocol Focus on silhouette of testicle Sweep superior to inferior Scan entire length of testicle Include entire width of testicle Hold midline short axis view of testicle Color Doppler and spectral Doppler images

Bilateral Testes: Short Axis Starting point – Transverse plane, anterior Transducer on anterior surface of scrotum Indicator toward patient’s right side Midline of scrotum Probe perpendicular to skin Taping protocol Focus on equal silhouette of both testicles Sweep superior to inferior Scan entire length of testicle Hold midline short axis view of testicle Color Doppler and spectral Doppler image

A03750-Ch12.qxd

9/8/05

1:26 PM

Page 211

CHAPTER

12

Ocular Scanning Protocol Paul Sierzenski

GOAL OF OCULAR ULTRASOUND Demonstrate abnormalities of the eye related to abnormal ocular architecture.

EMERGENCY ULTRASOUND APPROACH Emergency medicine ultrasound of the eye is focused on the clinical questions involving the eye. Patients with acute eye pain or visual complaints often will present to the emergency department for evaluation. The most common yes–no question to be addressed for these patients is that of retinal detachment. Other pathologic conditions of the eye such as intraocular foreign body, vitreous hemorrhage, increased optic nerve sheath diameter (associated with increased intracranial pressure), retrobulbar hematoma, and lens dislocation can be diagnosed with ultrasound. If an open globe rupture is suspected, ocular ultrasound is contraindicated.

ANATOMY • • • • • •

Anterior chamber Lens Posterior chamber Retina Optic nerve sheath Retrobulbar space

Posterior chamber

Retina Lens

Anterior chamber

Optic nerve Retrobulbar space

PATIENT POSITION • Supine • Semi-erect with the head of the bed at about 30 degrees

211

A03750-Ch12.qxd

212

9/8/05

1:26 PM

SECTION V

Page 212


PATIENT PREPARATION • Scan through a closed eye • Use ample gel directly on the closed lid • Little or no direct pressure on the globe itself

TRANSDUCER • High frequency linear – 7.5 to 10 MHz or potentially higher (12–15 MHz) • Lowest power settings (increased gain) that allow visualization (if adjustable)

ULTRASOUND IMAGES Ocular Essential Images • Eye (right and left) • Longitudinal • Transverse • Retrobulbar space • Optic nerve sheath

EYE: TRANSVERSE AXIS Landmarks • Ocular silhouette

Eyelid

Anterior chamber

Lens Posterior chamber

Retrobulbar space Optic nerve

A03750-Ch12.qxd

9/8/05

1:26 PM

Page 213

CHAPTER 12

Image Elements • Lens • Anterior chamber • Posterior chamber • Retrobulbar space • Optic nerve sheath

Ocular Scanning Protocol

Conjuctiva Anterior chamber

Eyelid Lens

Tricks of the Trade • Image the asymptomatic eye first for comparison. • Use ample gel. The eye sits somewhat recessed below the surrounding orbit and its ridge. • Stabilize your hand over the bridge of the nose and the forehead. • Consider keeping the probe stationary while having the patient move the eye under a closed lid to fully evaluate the orbit. • Cooling the ultrasound gel will increase its viscosity and help to keep it in the orbit. • Common artifacts cause poor imaging of the “sides” of the eye and false echoes within the posterior chamber.

Partial View Probe Positioning Note: Most partial views of the eye show some but not all of the elements listed above. With most atypical probe placements there will be no visualization of the eye.

213

A03750-Ch12.qxd

214

9/8/05

1:26 PM

SECTION V

Page 214


EYE: LONGITUDINAL AXIS Note: With normal anatomy, images in longitudinal axis will appear identical to images in transverse axis. Landmarks • Ocular silhouette

Retrobulbar space Anterior chamber Eyelid Optic nerve

Lens Posterior chamber

Image Elements • Lens • Anterior chamber • Posterior chamber • Retrobulbar space • Optic nerve sheath Partial View Probe Positioning Note: Most partial views of the eye show some but not all of the elements listed above. With most atypical probe placements there will be no visualization of the eye.

ULTRASOUND TECHNIQUE Still Image Protocol Eye: Longitudinal Axis, Midline Approach – Sagittal, anterior Transducer centered over closed eyelid Indicator toward patient’s forehead Probe perpendicular to face (initially) Orient probe through anterior chamber and optic nerve sheath

A03750-Ch12.qxd

9/8/05

1:26 PM

Page 215

CHAPTER 12

Eye: Longitudinal Axis, Lateral Approach – Sagittal, anterior Transducer lateral side of orbit Indicator toward patient’s forehead Probe perpendicular to face (initially) Orient probe parallel to midline view Eye: Longitudinal Axis, Medial Approach – Sagittal, anterior Transducer nasal side of orbit Indicator toward patient’s forehead Probe perpendicular to face (initially) Orient probe parallel to midline view Lens: Longitudinal Axis Approach – Sagittal, anterior Transducer centered over closed eyelid Indicator toward patient’s forehead Probe perpendicular to face Center lens in image


215

A03750-Ch12.qxd

216

9/8/05

SECTION V

1:26 PM

Page 216


Eye: Transverse Axis, Midline Approach – Transverse, anterior Transducer centered over closed eyelid Indicator toward patient’s right side Probe perpendicular to face Orient probe through anterior chamber and optic nerve sheath

Eye: Transverse Axis, Superior Approach – Transverse, anterior Transducer superior orbit Indicator toward patient’s right side Probe perpendicular to face Orient probe parallel to midline view Eye: Transverse Axis, Inferior Approach – Transverse, anterior Transducer inferior orbit Indicator toward patient’s right side Probe perpendicular to face Orient probe parallel to midline view Lens: Transverse Axis Approach – Transverse, anterior Transducer centered over orbit Indicator toward patient’s right side Probe perpendicular to face Center lens in image

A03750-Ch12.qxd

9/8/05

1:26 PM

Page 217

CHAPTER 12


VIDEOTAPE PROTOCOL Eye: Longitudinal Axis Starting point – Sagittal plane, anterior Transducer centered over orbit Indicator toward patient’s forehead Probe perpendicular to face Orient probe through anterior chamber and optic nerve sheath Taping protocol Center eye (anterior and posterior chamber) in image Sweep medial to lateral and back Sweep entire width of eye Include images of optic nerve sheath Include detailed images of lens and anterior chamber

217

A03750-Ch12.qxd

218

9/8/05

SECTION V

1:26 PM

Page 218


Eye: Transverse Axis Starting point – Transverse plane, anterior Transducer centered over orbit Indicator toward patient’s right side Probe perpendicular to face Orient probe through anterior chamber and optic nerve sheath Taping protocol Center eye (anterior and posterior chamber) in image Sweep superior to inferior and back Sweep entire length of eye Include images of optic nerve sheath Include detailed images of lens and anterior chamber

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 219

SECTION

VI NON-PROTOCOL DRIVEN ULTRASOUND GOAL OF NON-PROTOCOL DRIVEN ULTRASOUND This chapter will focus on ultrasounds that are not protocol driven. Non-protocol driven ultrasound focuses on clinical decisions prior to an invasive procedure or ultrasound imaging for guidance of an invasive procedure. Because these ultrasounds can vary widely in terms of probe location, pathology, and anatomy, this chapter is procedure driven rather than protocol driven. As with all applications of bedside ultrasound, documentation of the images using either still or video imagery is a necessary component of this practice.

NON-PROTOCOL ULTRASOUND AND PROCEDURE Musculoskeletal Ultrasound • Soft tissue ultrasound (ultrasound guided) Question – Abscess vs. cellulitis Procedure – Incision and drainage • Soft tissue ultrasound (ultrasound guided) Question – Location of foreign body Procedure – Removal of foreign body • Chest and chest wall imaging (ultrasound prior to procedure) Question – Detection of pneumothorax Procedure – Chest tube insertion • Spinal ultrasound Question – Location of spinous processes Procedure – Lumbar puncture

219

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 220

Ultrasound Guided Central Line Placement • Vascular ultrasound (ultrasound guided) Question – Location of internal jugular vein Procedure – Central venous catheterization • Vascular ultrasound (ultrasound guided) Question – Location of common femoral vein Procedure – Central venous catheterization Ultrasound Guided Fluid Drainage • Chest and chest wall imaging (ultrasound guided) Question – Detection of pleural fluid Procedure – Thoracentesis Question – Detection of pericardial fluid Procedure – Pericardiocentesis • Abdominal imaging (ultrasound guided procedure) Question – Detection of peritoneal fluid Procedure – Paracentesis

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 221

CHAPTER

Skin and Soft Tissue Ultrasound

13

J. Christian Fox and Romolo Gaspari

GOAL OF SOFT TISSUE ULTRASOUND Demonstrate abnormal structures in skin or superficial connective tissue or muscle.

ANATOMY Anatomy of interest depends on the location of the ultrasound. • Skin • Muscle • Tendon • Bony structures • Vessels Use known structures such as muscle, bone, and vessels as landmarks to reference the mass or object in question. These landmarks will vary depending on their location. For example, neck masses will have muscle, vascular, and thyroid tissue surrounding them, whereas abdominal wall masses will tend to have more fat and muscle surrounding them. Masses located in the extremities will typically have bony shadows, vessels, and muscle tissue as landmarks.

CLINICAL QUESTION • Cystic vs. solid mass • Abscess vs. cellulitis • Location of foreign body The answer to this question has clinical implications for possible future outpatient workup or immediate bedside interventions.

PATIENT POSITION • Varies depending on area being imaged

PATIENT PREPARATION • Remove distal jewelry • Clean skin of debris and particulate matter • Disinfect skin 221

A03750-Ch13.qxd

222

9/8/05

SECTION VI

1:27 PM

Page 222

Non-Protocol Driven Ultrasound

TRANSDUCER • High frequency linear probe

ULTRASOUND APPEARANCE OF SKIN AND SOFT TISSUE PATHOLOGY • • • •

Solid (echogenic mass) Cystic structure (anechoic round cyst with posterior enhancement) Hematoma (variable depending on time from onset) Foreign body (appearance depends on foreign body material and presence or absence of gas or surrounding fluid) • Abscess (hypoechoic with irregular borders) • Cellulitis (hyperechoic “islands” surrounded by small anechoic “lakes”)

ULTRASOUND IMAGES • Long axis of area being imaged • Short axis of area being imaged

Long Axis

Short Axis

ULTRASOUND TECHNIQUE: GENERAL • Position area of interest in center of monitor • Line center of probe over area of interest • Rotate probe 90 degrees counterclockwise and re-image • Identify surrounding items of interest (Example: Subcutaneous structure in groin—identify femoral artery, vein) Abscess vs. Cellulitis Bedside ultrasound answers the clinical question of whether or not an erythematous region of the skin also harbors a surgically drainable abscess beneath.

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 223

CHAPTER 13

Cellulitis


Abscess

Probe Selection • 5 to 7.5 MHz or higher • Linear • Highest resolution setting Ultrasound Technique: Abscess • Position probe over center of swelling or redness • Locate boundaries of fluid collection • Identify surrounding structures for location (Example: Abscess extends to bony surface of 3rd metacarpal) • Identify structures that may complicate incision and drainage (I & D) (Example: Abscess of wrist near radial artery)

Phlegmon Abscess

Bones

223

A03750-Ch13.qxd

224

9/8/05

SECTION VI

1:27 PM

Page 224


Procedure Technique Needle aspiration (static guidance) • Identify boundaries of abscess and corresponding surface landmarks • Mark or identify where needle will penetrate skin and angle of introduction of needle • Disinfect skin prior to introduction of needle • Introduce needle into skin • Aspirate while advancing needle into abscess • Repeat if needed Needle aspiration (dynamic guidance) • Disinfect skin prior to ultrasound • Identify largest area of fluid collection (probe in sterile cover) • Place area of fluid collection in center of screen • Introduce needle next to probe at center angling toward abscess • Aspirate as needle is advanced • Image needle as it penetrates abscess Incision and drainage (static guidance) • Identify boundaries of abscess and corresponding surface landmarks • Mark or identify where scalpel will cut skin (most superficial fluid collection or largest fluid collection) • Disinfect skin prior to incision • Incision of skin with blunt dissection of septations or loculations • Express with pressure around incision • Repeat as needed • Leave incision open and pack with sterile packing material Incision and drainage (dynamic guidance) • Identify boundaries of abscess and corresponding surface landmarks • Mark or identify where scalpel will cut skin (most superficial fluid collection or largest fluid collection) • Disinfect skin prior to incision • Introduce scalpel directly under center of probe • Ultrasound probe is removed once purulent material is encountered.

Tricks of the Trade • Cellulitis with localized edema will have low-level echoes in the “anechoic” space and can look like an abscess. • Gas-forming abscesses will cause comet tail artifacts that can blur the edges of the abscess. • Be conscious of identifying foreign bodies within the body of an abscess. • Re-image area of abscess following I & D or needle aspiration to monitor drainage.

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 225

CHAPTER 13


• Compression of an abscess often results in streaming or swirling of pus. • For deeper abscesses it may be necessary to use the lower range of frequencies or even a curved probe set to its higher frequency setting. • To identify point of incision during I & D locate probe over most superficial fluid collection, not largest fluid collection.

Image Elements • Body of abscess • Boundaries of abscess • Surrounding landmarks • Needle penetration (for ultrasound guided aspiration) Still Image Protocol Use known structures such as muscle, bone, and vessels as landmarks to reference the abscess in question. These landmarks will vary depending on their location. Preprocedure Imaging Identify longest length of abscess Identify surrounding anatomy Demonstrate abscess in two perpendicular planes Periprocedure Imaging Image needle penetrating abscess (in one plane) Postprocedure Imaging Image drained abscess cavity Identify any remaining fluid collections

Pre-needle

During Needle

225

A03750-Ch13.qxd

226

9/8/05

SECTION VI

1:27 PM

Page 226


Videotape Protocol Initial Image of Abscess Identify longest length of abscess Fan side to side Image entire abscess Identify surrounding anatomy Rotate 90 degrees counterclockwise Fan from top to bottom Identify surrounding structures Procedure Documentation (Real-Time Guidance of Needle Aspiration Only) Find largest pocket of fluid Image needle as it penetrates abscess Postprocedure imaging Image drained abscess cavity Identify any remaining fluid collections

FOREIGN BODY REMOVAL Localization and removal of a foreign body can be a time-consuming task often with fruitless results. Use of bedside ultrasound helps to pinpoint and retrieve the object in a timely fashion. Probe Selection • High frequency linear probe (at highest frequency) Ultrasound Technique: Foreign Body Localization • Position probe over area of interest (i.e., entrance wound) • Slowly scan area of maximal interest • Be willing to scan wider area if foreign body is not visualized initially • Foreign bodies appear as highly echogenic structures that reflect sound in a way that can cause reverberation artifacts or shadows. • Identify surrounding structures for localizing foreign body Procedure Technique: Foreign Body Removal • Locate foreign body • Center foreign body on screen • Introduce a needle along face of probe towards foreign body • When needle contacts foreign body, remove ultrasound • Incise down length of needle • Remove foreign body

A03750-Ch13.qxd

9/8/05

1:27 PM

Page 227

CHAPTER 13


Tricks of the Trade • Most foreign bodies are located very close to the skin surface and adequate visualization may require a standoff structure (e.g., a 250-cc bag of normal saline). • Most foreign bodies are not easily visualized on ultrasound regardless of if they are seen on x-ray. • “Creeping” the probe along the skin may identify weak artifact signals from smaller foreign bodies that are not apparent when moving the probe quickly. • Foreign bodies within an abscess may be silhouetted and easier to identify. • Set a time frame when attempting to localize a foreign body and quit when time is up to prevent spending too much time on the procedure.

Image Elements • Foreign body • Artifact from foreign body • Surrounding landmarks Muscles Foreign body Foreign body artifact Artery Vein Trachea

227

A03750-Ch13.qxd

228

9/8/05

SECTION VI

1:27 PM

Page 228


Still Image Protocol Use known structures such as muscle, bone, and vessels as landmarks to reference the location of the foreign body. These landmarks will vary depending on the location of the foreign body. • Identify foreign body or artifact of foreign body • Identify surrounding landmarks Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the foreign body removal.

A03750-Ch14.qxd

9/8/05

1:27 PM

Page 229

CHAPTER

Chest Wall Ultrasound for Pneumothorax

14

Romolo Gaspari and J. Christian Fox

GOAL OF CHEST WALL ULTRASOUND Identification of pneumothorax.

RATIONALE FOR CHEST WALL ULTRASOUND Using ultrasound allows you to identify the chest wall and pleural lining of the lung. A pneumothorax may result in requiring the placement of a chest tube to reinflate the lung.

ANATOMY • • • •

Ribs Lung Pleura (lining of lung) Intercostal muscle

Intercostal muscles

Lung

Ribs Ribs

229

A03750-Ch14.qxd

230

9/8/05

SECTION VI

1:27 PM

Page 230


PATIENT POSITION • Supine

PATIENT PREPARATION • None

TRANSDUCER • High-frequency linear probe

ULTRASOUND IMAGE ELEMENTS • Ribs • Lung edge (pleura) • Chest wall–lung interface

ULTRASOUND APPEARANCE OF PNEUMOTHORAX • During normal respiration the lung and chest wall “slide” past one another • Comet tail artifact (small white linear streaks) radiate away from the probe surface and migrate back and forth during respiration • Absence of normal findings indicate pneumothorax

Rib Intercostal muscles Comet tail artifact

A03750-Ch14.qxd

9/8/05

1:27 PM

Page 231

CHAPTER 14

Chest Wall Ultrasound for Pneumothorax

ULTRASOUND TECHNIQUE • • • • • •

Position probe on anterior chest wall Over 2nd–3rd or 3rd–4th rib space Mid-clavicular line, or, just lateral to sternum Indicator to patient’s head Hold probe between superior and inferior rib Hold probe stationary through multiple respiratory cycles Tricks of the Trade • Using M-mode provides alternative proof of pneumothorax. Place M-mode cursor between the rib shadows and observe a tracing consistent with lung sliding. A pneumothorax produces a continuous straight line along the M-mode tracing. • It is difficult to demonstrate a pneumothorax using still images alone. • Color power Doppler imaging of the chest wall–lung interface should show a signal flare in normal lung.

Still Image Protocol Approach – Sagittal plane, anterior Transducer on anterior chest Mid-clavicular line, or, just lateral to sternum Indicator toward head Probe perpendicular to skin Hold probe still during respiratory cycle

231

A03750-Ch14.qxd

232

9/8/05

SECTION VI

1:27 PM

Page 232


Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the sliding lung. There is no movement of probe during recording of ultrasound.

A03750-Ch15.qxd

9/8/05

1:28 PM

Page 233

CHAPTER

15

Ultrasound Guided Lumbar Puncture J. Christian Fox and Romolo Gaspari

GOAL OF ULTRASOUND GUIDED LUMBAR PUNCTURE Facilitate placement of spinal needle during lumbar puncture.

RATIONALE FOR ULTRASOUND GUIDED LUMBAR PUNCTURE Using ultrasound allows you to identify landmarks that are not palpable due to body habitus. In cases where anatomic landmarks are easily palpable, ultrasound guidance is not needed.

ANATOMY • Spinous process • Interspinal disk space • Connective tissue

Spinous process

Spinal cord L1

Inter-spinal ligament

Cauda equina

Lumbar disc Needle tract

Skin

Vertebral body

The bony landmarks appear as hyperechoic linear structures that completely reflect the sound, resulting in very distinct shadowing. When the probe is between two vertebrae, the intense reflection is no longer present and tissue can be visualized. It is between the bony landmarks that the needle needs to be directed to successfully obtain spinal fluid.

233

A03750-Ch15.qxd

234

9/8/05

SECTION VI

1:28 PM

Page 234


PATIENT POSITION • • • •

Sitting up, leaning forward, or Lateral decubitus Lumbar flexion Line up hips and shoulders to keep spine strait

PATIENT PREPARATION • Clean and disinfect skin

TRANSDUCER • High frequency linear probe (5–10 MHz)

ULTRASOUND IMAGE ELEMENTS • Spinous process • Intervertebral disk space

Spinous process

Disk space

Long Axis Spinous Process

Transverse View at Spinous Process

Transverse View between Spinous Process

A03750-Ch15.qxd

9/8/05

1:28 PM

Page 235

CHAPTER 15

Ultrasound Guided Lumbar Puncture

ULTRASOUND TECHNIQUE • • • •

Position probe on midline of back Indicator orientation is toward the head (long axis) (preferred), or Indicator towards right side Locate intervertebral space

Procedure Technique Still guidance • Place patient in proper position • Identify disk space • Mark location for needle insertion • Remove probe and disinfect skin • Anesthetize skin surface • Insert needle at predetermined spot on back Dynamic guidance • Disinfect skin surface • Place probe in sterile cover • Place patient in proper position • Identify disk space • Remove probe • Anesthetize skin surface over disk space • Re-image disk space • Move probe slightly to one side • Insert needle next to probe head at exact center of probe, angled slightly cephalad in relation to spine axis • Remove probe and continue lumbar puncture Alternative approach • Paramedian approach • Place ultrasound probe on patient’s back • Indicator towards head • 2–4 cm lateral to midline • Angle towards midline • Identify disk space • Mark spot for needle insertion site • Remove probe from skin surface • Sterilize skin surface • Insert needle Tricks of the Trade • If anatomic landmarks are palpable then ultrasound guidance is not needed. • Spinous processes are regularly repeating structures. Locating multiple superior spinal shadows give secondary indications where lower landmarks are located. • Flexing the lumbar spine as much as possible enlarges the disk space for introduction of the needle.

235

A03750-Ch15.qxd

236

9/8/05

SECTION VI

1:28 PM

Page 236


• With linear probes with a large footprint the length probe will span two vertebral transverse processes when placed in the sagittal plane. The left side of the monitor will show the superior vertebral shadow and the right side will show the inferior vertebral shadow. The needle should be placed between the two shadows. • Dynamic guidance during a lumbar puncture increases procedural complexity. Static guidance is usually adequate.

Still Image Protocol Approach – Posterior, longitudinal Transducer at midline of back Indicator toward head Probe perpendicular to skin Locate probe over L3 or L4 disk space Image disk space Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation locating the disk space or introducing the needle into the disk space. There is no movement of probe during procedure.

A03750-Ch16.qxd

9/8/05

1:28 PM

Page 237

CHAPTER

16

Vascular Procedure Ultrasound J. Christian Fox and Romolo Gaspari

VASCULAR ULTRASOUND Central Venous Cannulation Goal of Ultrasound for Central Venous Cannulation Facilitate placement of a venous catheter into a central vein. Rationale for Ultrasound Guided Central Line Placement • Ultrasound imaging allows you to align the probe, the vein, and the needle tip • Visualization under real-time guidance reduces complications resulting from multiple attempts One vs. Two Operator Technique One operator technique • Probe in one hand • Introducer needle in other Two operator technique • One person holds probe • The other person advances needle

ULTRASOUND GUIDED INTERNAL JUGULAR VEIN CANNULATION Anatomy Use known structures such as muscle and vessels as landmarks • Internal jugular vein • Subclavian vein • Carotid artery • Trachea • Neck muscles Patient Position • Supine • Trendelenburg • Head turned to left (for right internal jugular) • Head turned to right (for left internal jugular)

Carotid artery

Internal jugular vein Sternocleidomastoid muscle

237

A03750-Ch16.qxd

238

9/8/05

SECTION VI

1:28 PM

Page 238


Patient Preparation • Clean and disinfect skin Transducer • High frequency linear probe

Ultrasound Image Elements • Internal jugular vein • Carotid artery • Sternocleidomastoid muscle • Trachea • Needle tip, or, ring down artifact

Ultrasound Technique • Position probe on right lateral neck (right internal jugular) • Indicator to patient’s right • Center internal jugular vein on screen • Hold probe completely still during needle advancement Procedure Technique Venous cannulation (static guidance) • Identify vasculature structures • Avoid puncturing sternocleidomastoid muscle • Note location of internal anatomy in relation to external anatomy • Identify needle entry point on skin • Remove probe from skin • Disinfect skin prior to introducing needle • Insert central line at predetermined point using Seldinger technique

A03750-Ch16.qxd

9/8/05

1:28 PM

Page 239

CHAPTER 16

Vascular Procedure Ultrasound

Venous cannulation (dynamic guidance) • Identify vascular structures • Avoid puncturing sternocleidomastoid muscle • Identify needle entry point • Hold needle at center of ultrasound probe, same distance from probe as vein is deep to probe (see figure) • Introduce needle at 45-degree angle • Image needle as it enters vein • Wall distends inward as needle pushes in • Wall snaps back outward as needle punctures wall

A

Probe A

45°

Tricks of the Trade • Having the patient perform a Valsalva maneuver distends the vein and increases the chances of a successful line placement. • The walls of the vein may tent inward when the needle approaches the vein. Extreme tenting (i.e., low vascular volume) may result in complete penetration of the anterior and posterior vein wall. • Redirecting the needle once inside the patient during a difficult line placement will most likely result in no ultrasound guidance of the procedure. If the first pass is unsuccessful then remove needle from patient and start again from the beginning. • The anatomy of the neck is mobile. If the patient moves (i.e., turns the head) after the static ultrasound but prior to inserting the needle, then the patient must be re-imaged prior to attempting line placement.

239

A03750-Ch16.qxd

240

9/8/05

SECTION VI

1:28 PM

Page 240


• Small rapid in-line movements of the needle (i.e., jiggling) during line placement will locate the needle tip on the screen by transmitting these movements to surrounding tissue. • Jugular veins become noncompressible when a clot is contained within their lumen. Always confirm patency of the jugular vein by compressing it prior to cannulation attempt. If not compressible, consider using the contralateral side.

Still Image Protocol Approach – Transverse plane, anterior Transducer at right lateral neck Indicator toward right side Probe perpendicular to skin Image vein prior to introduction of needle Image vein during introduction of needle

Internal jugular vein Carotid artery

Internal jugular vein

Needle Carotid artery

A03750-Ch16.qxd

9/8/05

1:28 PM

Page 241

CHAPTER 16


Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the introduction of the needle into the vein. There is no movement of probe during procedure.

241

A03750-Ch16.qxd

242

9/8/05

SECTION VI

1:28 PM

Page 242


ULTRASOUND GUIDED COMMON FEMORAL VEIN CANNULATION Anatomy Use known structures such as muscles and vessels as landmarks • Common femoral vein • Common femoral artery • Great saphenous vein Patient Position • Supine • Reverse Trendelenburg

Femoral artery

Common femoral

Profunda femoris

Patient Preparation • Clean and disinfect skin Popliteal artery

Transducer • High-frequency linear probe

Popliteal

Great saphonous

Ultrasound Image Elements • Common femoral vein • Common femoral artery • Needle tip, ring down artifact

Vein Artery

Needle (not seen) Vein Artery

A03750-Ch16.qxd

9/8/05

1:28 PM

Page 243

CHAPTER 16


Ultrasound Technique • Position probe on right or left thigh at inguinal ligament • Indicator to patient’s right • Center common femoral vein on screen • Hold probe completely still during needle advancement Procedure Technique Venous cannulation (static guidance) • Identify vasculature structures • Note location of internal anatomy in relation to external anatomy • Identify needle entry point on skin • Disinfect skin prior to introducing needle • Remove probe from skin surface • Anesthetize skin surface • Insert central line at predetermined point using Seldinger technique Venous Cannulation (Dynamic Guidance) • Identify vascular structures • Identify needle entry point • Hold needle at center of ultrasound probe, same distance from probe as vein is deep to probe (see figure below) • Anesthetize skin surface • Introduce needle at 45-degree angle • Image needle as it enters vein • Wall distends inward as needle pushes in • Wall snaps back outward as needle punctures wall • Complete line placement using Seldinger technique

A

Probe A

45°

Tricks of the Trade • The walls of the vein may tent inward when the needle approaches the vein. Extreme tenting (i.e., low vascular volume) may result in complete penetration of the anterior and posterior vein wall.

243

A03750-Ch16.qxd

244

9/8/05

SECTION VI

1:28 PM

Page 244


• Redirecting the needle once inside the patient during a difficult line placement will most likely result in no ultrasound guidance of the procedure. If the first pass is unsuccessful then remove needle from patient and start again from the beginning. • Small rapid in-line movements of the needle (i.e., jiggling) during line placement will locate the needle tip on the screen by transmitting these movements to surrounding tissue. • Veins become noncompressible when a clot is contained within their lumen. Always confirm patency of the vein by compressing it prior to cannulation attempt. If not compressible, consider using the contralateral side.

Still Image Protocol Approach – Transverse plane, anterior Transducer at thigh Caudal to inguinal ligament Indicator toward right side Probe perpendicular to skin Image vein prior to introduction of needle Image vein during introduction of needle

Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the introduction of the needle into the vein. There is no movement of probe during procedure.

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 245

CHAPTER

Ultrasound Guided Fluid Drainage

17

J. Christian Fox and Romolo Gaspari

Ultrasound Guided Thoracentesis GOAL OF ULTRASOUND GUIDED THORACENTESIS Facilitate draining fluid collections in the chest.

RATIONALE FOR ULTRASOUND GUIDED THORACENTESIS Using ultrasound allows you to avoid puncturing the lung or liver by localizing an area of maximal fluid collection. If loculations are encountered, selective aspiration can be accomplished under real-time guidance.

ANATOMY • • • • • • • •

Rib Scapula Liver Spleen Diaphragm Lung Intercostal muscles Clavicle Lung Spleen Kidney

Liver

245

A03750-Ch17.qxd

246

9/8/05

SECTION VI

1:29 PM

Page 246


Subclavian vein

Clavicle Scapula Intercostal muscles Ribs Ribs Lung

Diaphragm

Note: Organs of the abdomen move cranially and caudally with expiration and inspiration, respectively, as the diaphragm contracts and relaxes. At full expiration the liver and spleen can be as high at the 10th thoracic rib.

PATIENT POSITION • Sitting (preferred) • Leaning forward


TRANSDUCER • High-frequency linear probe • Micro-convex curved probe (3–5 MHz) or • Phased array probe or • Linear probe (5–7 MHz)

ULTRASOUND IMAGE ELEMENTS • • • • •

Ribs Lung edge (pleura) Diaphragm (if inferior) Liver (if right side inferior) Spleen (if left side inferior)

Ultrasound Appearance of Fluid in the Thorax • Free fluid in the chest should accumulate in a dependent area • Loculated fluid in the chest may accumulate in pockets at any location

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 247

CHAPTER 17

Ribs


Intercostal muscles

Pleural fluid Lung

ULTRASOUND TECHNIQUE • • • • • •

Position probe on lower, posterior chest wall Indicator to patient’s head Locate largest fluid collection Identify superior border of fluid collection Identify rib space where needle will be inserted Image at point of needle insertion through multiple inspiratory and expiratory cycles to identify movement of internal organs

Procedure Technique Still guidance • Identify fluid collection • Map superior border of fluid collection • Identify location for needle insertion • Over largest pocket of fluid • Avoid internal organs (at full expiration) • Avoid neurovascular bundles under rib • Remove probe and disinfect skin • Anesthetize skin surface • Insert needle at predetermined spot on chest wall Dynamic guidance • Disinfect skin surface • Place probe in sterile cover • Identify fluid collection • Map superior border of fluid collection • Identify location for needle insertion • Over largest pocket of fluid • Avoid internal organs (at full expiration) • Avoid neurovascular bundles under rib • Anesthetize skin surface • Insert needle next to probe head at exact center of probe, angled toward fluid • Once fluid begins to flow into the syringe, the probe is securely placed aside and the procedure continues in the usual fashion. The hyperechoic ring down artifact represents the metallic needle. Lung is seen as a hyperechoic homogenous structure containing occasional air shadows. It moves in and out as the patient breathes.

247

A03750-Ch17.qxd

248

9/8/05

SECTION VI

1:29 PM

Page 248


Tricks of the Trade • In cases in which loculations are present, the probe can be continued to be used in order to guide the needle to the various loculations while taking care to avoid the lung. • Dynamic guidance during a thoracentesis increases procedural complexity. Static guidance is usually adequate. • Rotating probe may provide better imaging between ribs, but may make realtime guidance more challenging. Still Image Protocol Approach – Longitudinal plane, anterior Transducer at lower posterior thorax Indicator toward head Probe perpendicular to skin Angle and sweep stationary probe if needed to better visualize fluid Image fluid collection prior to introduction of needle Image needle entering fluid collection Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the introduction of the needle into the fluid collection. There is no movement of probe during procedure.

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 249

CHAPTER 17


Ultrasound Guided Paracentesis GOAL OF ULTRASOUND GUIDED PARACENTESIS Facilitate draining fluid collections in the abdomen

RATIONALE FOR ULTRASOUND GUIDED PARACENTESIS Using ultrasound allows you to avoid puncturing internal organs by localizing an area of maximal fluid collection. It increases the chances of a successful drainage when a small amount of fluid is present.

ANATOMY • • • • • •

Liver Spleen Small bowel Large bowel Bladder Inferior epigastric artery

Spleen Inferior epigastric artery

Liver Bladder

Note: The umbilicus marks the center of the abdomen. The needle should be introduced inferior or lateral to the umbilicus. Be sure to avoid the bladder (inferior) and inferior epigastric vasculature (lateral).

PATIENT POSITION • Supine • Lateral decub


TRANSDUCER • Curved probe (3–5 MHz) • Linear probe (5–10 MHz)

ULTRASOUND IMAGE ELEMENTS • • • •

Abdominal wall Bowel loops Free fluid Needle

249

A03750-Ch17.qxd

250

9/8/05

SECTION VI

1:29 PM

Page 250


Free fluid

Needle Needle artifact

Bowel loops

Ultrasound Appearance of Free Fluid in the Abdomen • Free fluid will present as anechoic shapes with sharp angles • Fluid in structures (bladder and bowel) will present as anechoic rounded shapes • Free fluid in the abdomen should accumulate in dependent areas • Most dependent area when standing is the pelvis • Most dependent area when lying down is Morison’s pouch • Large amounts of fluid will present as floating bowel loops

Abdominal wall Free fluid

Bowel loops

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 251

CHAPTER 17

Bowel loops


Bladder

Free fluid

ULTRASOUND TECHNIQUE • • • •

Position probe on anterior abdominal wall Indicator orientation is variable Locate largest fluid collection Identify structures bordering fluid collection The hyperechoic ring down artifact represents the metallic needle. Bowel gas presents as hazy linear shadows extending away from probe. Procedure Technique Still guidance • Identify fluid collections • Delineate borders of fluid collection • Identify location for needle insertion • Remove probe and disinfect skin • Anesthetize skin surface • Insert needle at predetermined spot on abdominal wall Dynamic guidance • Disinfect skin surface • Place probe in sterile cover • Identify fluid collection • Delineate borders of fluid collection • Identify location for needle insertion • Anesthetize skin surface • Insert needle next to probe head at center of probe, angled toward fluid • Once fluid begins to flow into the syringe, the probe is placed aside and the procedure continues in the usual fashion

251

A03750-Ch17.qxd

252

9/8/05

SECTION VI

1:29 PM

Page 252


Tricks of the Trade • Avoid inserting needle too inferiorly and therefore risk puncturing the bladder. • Many patients with ascites have hepatosplenomegaly. Avoid inserting needle too superiorly as this can lead to liver and spleen punctures. • Placing patient in lateral decubitus or reverse Trendelenburg may concentrate fluid and enable a successful procedure. • In cases in which loculations are present, the probe can be continued to be used in order to guide the needle to the various loculations while taking care to avoid bowel, bladder, liver, and spleen. • Identify structures between probe and fluid to prevent complications during needle insertion. • Continued ultrasound during the fluid drainage may identify occlusion of catheter tip by bowel loops.

Still Image Protocol Approach – Anterior abdomen Transducer inferior and lateral to umbilicus Indicator direction variable Probe perpendicular to skin Locate probe over fluid collection Image fluid collection prior to introduction of needle Image needle entering fluid collection Videotape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the introduction of the needle into the fluid collection. There is no movement of probe during procedure.

ULTRASOUND GUIDED PERICARDIOCENTESIS Goal of Ultrasound Guided Pericardiocentesis Facilitate draining fluid in the pericardium around the heart Rationale for Ultrasound Guided Pericardiocentesis Using ultrasound allows you to visualize fluid collections in the pericardium. Using ultrasound guidance allows you to visualize introduction of the needle into the pericardium and avoid contact with the heart. Ultrasound guidance is not always needed and pericardiocentesis can be performed ‘blind’.

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 253

CHAPTER 17


ANATOMY • • • •

Diaphragm

Heart Diaphragm Liver Pericardial space Heart

PATIENT POSITION • Supine

Liver

Most pericardiocentesis performed in the emergency department are in patients with decreasing or unstable clinical status and are performed in a supine position.


TRANSDUCER • Curved probe (3–5 MHz) • Phased array probe (2–4 MHz)

ULTRASOUND IMAGE ELEMENTS • • • •

Liver Cardiac Silouette Pericardial Space Needle

Liver

Diaphragm Heart

Needle

Pericardium

Ultrasound Appearance of Pericardial Effusion • Free fluid around the heart will appear as an anechoic rim • Pericardial fat pads can appear as a hypoechoic area next to the heart • Note – pericardial fat does not commonly surround the heart

253

A03750-Ch17.qxd

254

9/8/05

SECTION VI

1:29 PM

Page 254


Ultrasound Technique • Position probe sub-costal • Indicator orientation is to patient’s right • Position heart in center or right of image • Image needle as it enters the pericardial space Needle may appear as distinct linear shape or indistinct hyperechoic object with ring down artifact. Ring down artifact is repeating linear echoes posterior to needle. Procedure Technique Still Guidance • Identify fluid collections • Delineate extent of pericardial effusion • Identify location for needle insertion • Remove probe and disinfect skin (if time permits) • Insert needle at pre-determined spot on abdominal wall in direction of heart Dynamic Guidance • Disinfect skin surface • Place probe in sterile cover • Identify fluid collection • Delineate extent of pericardial effusion • Identify location for needle insertion • Insert needle in epigastrium angling towards heart • Maneuver probe to image needle entering pericardium • Once fluid begins to flow into the syringe, the probe is placed aside and the procedure continues in the usual fashion Tricks of the Trade • Pericardial fat pads can mimic effusions Fat pads are not circumferential Diameter of fat pad does not change as heart beats There are usually echoes in fat pads • If the epigastrim is too crowded, move the ultrasound probe and image from left or right sub-costal.

Still Image Protocol Approach – Anterior Abdomen Transducer inferior to xyphoid process Indicator direction to patient’s right Probe at shallow angle to abdominal wall Locate heart in center of screen Image pericardial fluid collection prior to introduction of needle Image needle entering pericardium

A03750-Ch17.qxd

9/8/05

1:29 PM

Page 255

CHAPTER 17


Video Tape Protocol Video documentation of ultrasound uses the same landmarks and positioning as stills, but video allows for a dynamic documentation of the introduction of the needle into the fluid collection. There is no movement of probe during procedure. Ultrasound may offer additional information on cardiac performance following procedure.

255

A03750-Index.qxd

9/8/05

1:30 PM

Page 257

INDEX

A Abdomen focused assessment sonography of trauma and, 27–118, 29–55 anatomy and, 29–30 essential and optional images in, 31 left upper quadrant scan in, 37–39 patient position in, 31 right upper quadrant scan in, 34–36 still image protocol in, 44–50 subxiphoid scan in, 32–34 suprapubic scan in, 39–44 transducer in, 31 videotape protocol in, 51–55 gallbladder ultrasound and, 57–76 anatomy in, 58 essential and optional images in, 60 long axis view in, 60–63 pathology in, 59 short axis view in, 63–66 still image protocol in, 69–73 videotape protocol in, 73–76 renal ultrasound and, 77–104 anatomy and, 77 bladder scan, short axis view in, 92–93 bladder scan, still image protocol in, 98–99 bladder scan, videotape protocol in, 103–104 essential images in, 78–79 inferior pole obscured in, 94 left kidney, long axis view in, 85–87 left kidney, short axis view in, 87–91 left kidney, still image protocol in, 96–97 left kidney, videotape protocol in, 102–103 obese patient and, 93 patient position in, 78 patient preparation for, 78 renal pathology and, 78 rib shadows and, 93 right kidney, long axis view in, 79–82 right kidney, short axis view in, 82–85 right kidney, still image protocol in, 94–96 right kidney, videotape protocol in, 100–102 ultrasound appearance of free fluid in, 250 Abscess cellulitis versus, 222 ultrasound technique for, 223–226 Adnexa, endovaginal view, 137 Anechoic, term, 4 Anterior, term, 4 Anterior cul-de-sac, 30 Aorta scanning protocol, 159–182 anatomy and, 159–161 aorta versus vena cava and, 176

longitudinal low view, 167–169 superior view, 162–166 pathology and, 161 still image protocol in, 176–180 transverse low view, 173–175 middle view, 171–172 superior view, 169–170 videotape protocol in, 181–182 Apical four chamber view of heart, 111–112, 116 Apical two chamber view of heart, 112, 116 Axes, 12–14

B Bilateral testicle, short axis view, 205–206 Biliary sludge, 59 Bladder focused assessment sonography of trauma and, 39–40 short axis view of, 92–93 still image protocol for, 98–99 videotape protocol for, 103–104

C Cannulation common femoral vein, 242–244 internal jugular vein, 237–241 Cardiac scanning protocol, 105–118 anatomy and, 105 apical four chamber view in, 111–112, 116 apical two chamber view in, 112, 116 essential images in, 107 parasternal long axis view in, 114 parasternal short axis view in, 110–111, 115 pathology in, 106 still image protocol in, 112–113 subxiphoid short axis view in, 118 subxiphoid/subcostal view in, 113 subxiphoid view in, 107–109 suprasternal notch view in, 117 video image protocol in, 113 Caudad, term, 4 Celiac artery, 160, 161 Cellulitis, abscess versus, 222 Central line placement, ultrasound guided, 220, 237 Cephalad, term, 4 Chest wall ultrasound for pneumothorax, 229–232

257

A03750-Index.qxd

258

9/8/05

1:30 PM

Page 258

Index

Common bile duct ultrasound, 71–72 long axis view in, 66–67, 75 pathology in, 59 short axis view in, 68–69, 76 Common femoral vein, 184, 186–189 cannulation of, 242–244 Coronal axis, 12–14 Costophrenic angle view, 43, 49–50, 54–55 Cyst ovarian, 123, 142 renal, 78 Cystic, term, 4

D Descriptive terms, 4 Documentation, 8 Doppler ultrasound, 141

E Emergency ultrasound, 3–8 concept of, 5, 6–7 definitions in, 4 image documentation and, 8 issues in, 5–6 patient disclosures and, 7 technique in, 7 Endovaginal view in first trimester scan still image protocol and, 135–136 uterus long axis, 126–128 uterus short axis, 130–134 videotape protocol and, 139 in ovarian scan, 143–147 coronal, 146–147, 153–154 sagittal, 144–145, 152 Epididymis, 196 sagittal view of, 199–200 Extrahepatic ductal system, 58 Eye, 211–218 anatomy of, 211 longitudinal axis view of, 214 patient position for scan, 211 patient preparation for scan, 212 still image protocol for, 214–216 transducer for, 212 transverse axis view of, 212–213 videotape protocol for, 217–218

F Fanning through movement, 16–18 FAST. See Focused assessment sonography of trauma. Female bladder, focused assessment sonography of trauma and, 40 Femoral artery, 184, 186–189 Femoral vein cannulation, 242–244 First trimester scan, 121–140 anatomy in, 121–122 essential images in, 124 pathology in, 123

still image protocol in, 134–137 transabdominal, uterus on top of bladder view, 134 uterus long axis, endovaginal view, 126–128 uterus long axis, transabdominal view, 124–126 uterus short axis, endovaginal view, 130–134 uterus short axis, transabdominal view, 129–130 videotape protocol in, 138–140 Fluid drainage, ultrasound guided, 220, 245–254 in paracentesis, 249–252 in pericardiocentesis, 252–254 in thoracentesis, 245–248 Focused assessment sonography of trauma, 29–55 anatomy and, 29–30 essential and optional images in, 31 left upper quadrant scan in, 37–39 patient position in, 31 right upper quadrant scan in, 34–36 still image protocol in, 44–50 subxiphoid scan in, 32–34 suprapubic scan in, 39–44 transducer in, 31 videotape protocol in, 51–55 Foreign body removal, 226–228

G Gallbladder ultrasound, 57–76 anatomy in, 58 essential and optional images in, 60 long axis view in, 60–63 pathology in, 59 short axis view in, 63–66 still image protocol in, 69–73 videotape protocol in, 73–76 Gallstones, 59 Great saphenous vein, 184

H Heart, 105–118 anatomy of, 105 apical four chamber view of, 111–112, 116 apical two chamber view of, 112, 116 essential images in scanning of, 107 parasternal long axis view of, 114 parasternal short axis view of, 110–111, 115 pathology of, 106 pericardiocentesis and, 252–254 still image protocol for, 112–113 subxiphoid short axis view of, 118 subxiphoid/subcostal view of, 113 subxiphoid view of, 107–109 suprasternal notch view of, 117 video image protocol for, 113 Hepatic artery, 161 Hepatic duct scan, 71–72, 75–76 Heterogenous, term, 4 Homogenous, term, 4 Hydronephrosis, 78 Hyperechoic, term, 4 Hypoechoic, term, 4

A03750-Index.qxd

9/8/05

1:30 PM

Page 259

Index

I Iliac artery, 160 Image documentation, 8 Image elements, 4 Incision and drainage, 224 Inferior, term, 4 Inferior vena cava, 160 Inguinal region, 183 Initial orientation in ultrasound, 10–12 Internal jugular vein cannulation, 237–241 Isoechoic, term, 4

K Kidney, 77–104 inferior pole obscured, 94 left long axis view of, 85–87 short axis view of, 87–91 still image protocol for, 96–97 videotape protocol for, 102–103 obese patient and, 93 renal pathology and, 78 rib shadows and, 93 right long axis view of, 79–82 short axis view of, 82–85 still image protocol for, 94–96 videotape protocol for, 100–102 Kidney stones, 78

L Left kidney long axis view of, 85–87 short axis view of, 87–91 still image protocol for, 96–97 videotape protocol for, 102–103 Left upper quadrant, 29 focused assessment sonography of trauma and, 37–39 still image protocol in, 46 videotape protocol in, 52 Long axis, 12–14 Long axis view in aorta scan, 181–182 coronal, 180 low, 178 mid, 177 superior, 176 in common bile duct scan, 66–67, 75 in first trimester scan endovaginal, 126–128 still image protocol and, 134–136 transabdominal, 124–126 videotape protocol and, 138 in focused assessment sonography of trauma female bladder and, 40 male bladder and, 39 subxiphoid area and, 32–34 in gallbladder scan, 60–63

still image protocol and, 69–70 videotape protocol and, 73–74 in renal scan bladder and, 98–99, 103–104 left kidney and, 85–87, 96 right kidney and, 79–82, 94–96 in testicle scan, 198–201, 209 coronal or sagittal, 209 inferior, 200–201 lateral, parasagittal, 207 lateral or medial, 200 medial, parasagittal, 207 middle, 198–199 sagittal, 206 superior, 199–200 Longitudinal axis view in aorta scan low view in, 167–169 superior view in, 162–166 in ocular scan, 214–215, 217 Lower extremity vascular scanning protocol, 183–192 anatomy and, 183–184 common femoral artery and vein, 186–189 essential images in, 185–186 patient position for, 184 still image protocol in, 189–191 transducer for, 184 videotape protocol in, 191–192 Lumbar puncture, 233–236

M Male bladder, focused assessment sonography of trauma and, 39–40 Mechanics of ultrasound, 9–26 axes and, 12–14 basic movements in, 9 fanning through image in, 16–18 initial orientation in, 10–12 pushing in probe in, 24–26 rocking of probe in, 19–21 rotating probe in, 22–23 sliding along image in, 14–16 Medial thigh, 183 Musculoskeletal ultrasound, 219

N Needle aspiration of abscess, 224 Non-protocol driven ultrasound, 219–220

O Obese patient, renal ultrasound and, 93 Oblique, term, 23 Oblique axis, 12–14 Oblique view of right kidney, 82 Ocular scanning protocol, 211–218 anatomy and, 211 longitudinal axis view in, 214 patient position for, 211

259

A03750-Index.qxd

260

9/8/05

1:30 PM

Page 260

Index

Ocular scanning protocol, (Cont’d) patient preparation for, 212 still image protocol in, 214–216 transducer for, 212 transverse axis view in, 212–213 videotape protocol in, 217–218 Ovarian cyst, 123, 142 Ovarian scanning protocol, 141–156 anatomy and, 142 endovaginal, coronal, 146–147 endovaginal, sagittal, 144–146 essential images in, 143 pathology and, 123, 142 pelvic cul-de-sacs and, 150–151 still image protocol in, 152–154 transabdominal sagittal, 148 transverse, 148–149 videotape protocol in, 155–156

P Paracentesis, 249–254 Parasternal area, 30 Parasternal long axis view, 44, 48, 114 Parasternal short axis view, 110–111, 115 Partial view probe positioning, 5 in aorta scan longitudinal, low, 167 longitudinal, superior, 162, 165 transverse, low, 173 transverse, middle, 171 transverse, superior, 169–170 in common bile duct scan, 67, 69 in first trimester scan uterus long axis, endovaginal, 127 uterus long axis, transabdominal, 125 uterus short axis, endovaginal, 131 uterus short axis, transabdominal, 129 in focused assessment sonography of trauma, 41 left upper quadrant and, 37 right upper quadrant and, 35 subxiphoid area and, 32 in gallbladder scanning, 61, 65 in ovarian scan endovaginal, coronal, 147 endovaginal, sagittal, 145–146 pelvic cul-de-sacs, 150–151 transabdominal, sagittal, 148 transabdominal, transverse, 148–149 in renal scan, 91 bladder and, 92 left kidney, long axis view, 86 left kidney, short axis view, 89 right kidney, long axis view, 80 right kidney, short axis view, 84 in testicle scan, 201, 204, 205 Partial view ultrasound images, 4 Patient disclosure, 7 Patient position for aorta scan, 161 for cardiac scan, 106

for chest wall ultrasound for pneumothorax, 230 for common femoral vein cannulation, 242 for first trimester scan, 123 for focused assessment sonography of trauma, 31 for gallbladder ultrasound, 58 for internal jugular vein cannulation, 237 for lower extremity vascular scan, 184 for ocular scan, 211 for ovarian scan, 142 for paracentesis, 249 for renal ultrasound, 78 for skin and soft tissue ultrasound, 221 for testicle scan, 196 for thoracentesis, 246 for ultrasound guided lumbar puncture, 234 Patient preparation for common femoral vein cannulation, 242 for first trimester scan, 123 for gallbladder ultrasound, 58 for internal jugular vein cannulation, 238 for ocular scan, 212 for ovarian scan, 142 for paracentesis, 249 for pericardiocentesis, 253 for renal ultrasound, 78 for skin and soft tissue ultrasound, 221 for testicle scan, 196 for thoracentesis, 246 for ultrasound guided lumbar puncture, 234 Pelvic cul-de-sacs, 150–151, 154, 156 Pelvic protocols, 119–156 first trimester scan and, 121–140 anatomy in, 121–122 essential images in, 124 pathology in, 123 still image protocol in, 134–137 transabdominal, uterus on top of bladder, 134 uterus long axis, endovaginal, 126–128 uterus long axis, transabdominal, 124–126 uterus short axis, endovaginal, 130–134 uterus short axis, transabdominal, 129–130 videotape protocol in, 138–140 ovarian scan and, 141–156 anatomy and, 142 endovaginal, coronal, 146–147 endovaginal, sagittal, 144–146 essential images in, 143 pathology and, 123, 142 pelvic cul-de-sacs, 150–151 still image protocol in, 152–154 transabdominal, sagittal, 148 transabdominal, transverse, 148–149 videotape protocol in, 155–156 Pericardial effusion, 106, 253 Pericardial space scan, 54 Pericardiocentesis, 252 Peritoneal blood, focused assessment sonography of trauma for, 29 Pneumothorax, 229–232 Popliteal artery, 184, 190–191 Popliteal fossa, 183 Posterior cul-de-sac, 30

A03750-Index.qxd

9/8/05

1:30 PM

Page 261

Index

Pregnancy, first trimester scan, 121–140 anatomy in, 121–122 essential images in, 124 pathology in, 123 still image protocol in, 134–137 transabdominal, uterus on top of bladder view, 134 uterus long axis view endovaginal, 126–128 transabdominal, 124–126 uterus short axis view endovaginal, 130–134 transabdominal, 129–130 videotape protocol in, 138–140 Prevertebral space, 160 Probe movements, 4, 10–26 axes and, 12–14 fanning through image, 16–18 initial orientation in, 10–12 pushing in probe, 24–26 rocking of probe, 19–21 rotating of probe, 22–23 sliding along image, 14–16 Profunda femoris, 184 Protocol, defined, 4 Pushing in probe movement, 24–26

R Rectouterine space, 30 Renal cyst, 78 Renal stones, 78 Renal ultrasound, 77–104 anatomy and, 77 bladder short axis view of, 92–93 still image protocol for, 98–99 videotape protocol for, 103–104 essential images in, 78–79 inferior pole obscured in, 94 left kidney long axis view of, 85–87 short axis view of, 87–91 still image protocol for, 96–97 videotape protocol for, 102–103 obese patient and, 93 patient position in, 78 patient preparation for, 78 renal pathology and, 78 rib shadows and, 93 right kidney long axis view of, 79–82 short axis view of, 82–85 still image protocol for, 94–96 videotape protocol for, 100–102 Rib shadow, 93 Right kidney long axis view of, 79–82 short axis view of, 82–85 still image protocol for, 94–96 videotape protocol for, 100–102 Right upper quadrant, 29

focused assessment sonography of trauma and, 34–36 still image protocol in, 44–45 videotape protocol in, 51 Rocking of probe movement, 19–21 Rotating, term, 4 Rotation of probe movement, 22–23

S Shallow, term, 4 Short axis, 12, 13 Short axis view in aorta scan, 182 low, 180 mid, 179 superior, 178 in common bile duct scan, 68–69, 76 still image protocol and, 72 videotape protocol and, 76 in first trimester scan uterus, endovaginal, 130–134, 137 uterus, transabdominal, 129–130, 136 videotape protocol and, 139 in focused assessment sonography of trauma female bladder and, 40 subxiphoid area and, 32–34 in gallbladder scan, 63–66 still image protocol and, 70 videotape protocol and, 74 in lower extremity vascular scan common femoral vein and artery, 189–190, 191 popliteal vein and artery, 190–191, 192 in renal scan bladder and, 92–93 left kidney and, 87–91, 96, 97 right kidney and, 82–85, 96 in testicle scan bilateral, 205–206, 208, 210 inferior, 204, 208 middle, 201–203, 207 superior, 203, 207 Skin and soft tissue ultrasound, 221–228 anatomy and, 221 foreign body removal and, 226–228 general technique in, 222–225 patient position for, 221 patient preparation for, 221 transducer for, 222 Sliding, term, 4 Sliding movement along image, 14–16 Sludge, 59 Soft tissue ultrasound, 221–228 anatomy and, 221 foreign body removal and, 226–228 general technique in, 222–225 patient position for, 221 patient preparation for, 221 transducer for, 222 Spinal cord, ultrasound guided lumbar puncture and, 233–236

261

A03750-Index.qxd

262

9/8/05

1:30 PM

Page 262

Index

Spinning through image movement, 22–23 Splenic artery, 161 Still image protocol for abscess, 225 for aorta scan, 176–180 for cardiac scan, 112–113 for chest wall ultrasound for pneumothorax, 231 for common femoral vein cannulation, 244 for first trimester scan, 134–137 for focused assessment sonography of trauma, 44–50 for foreign body removal, 228 for gallbladder ultrasound, 69–73 for internal jugular vein cannulation, 240 for ocular scan, 214–216 for ovarian scan, 152–154 for paracentesis, 252 for pericardiocentesis, 254 for renal scan bladder and, 98–99 left kidney and, 96–97 right kidney and, 94–96 for skin and soft tissue ultrasound, 225, 228 for testicle scan, 206–209 for thoracentesis, 248 for ultrasound guided lumbar puncture, 236 Subxiphoid area, 30 Subxiphoid/subcostal view in cardiac scan, 113 Subxiphoid view in cardiac scan, 107–109, 118 in focused assessment sonography of trauma, 32–34 still image protocol in, 46 videotape protocol in, 52 Superior, term, 4 Superior mesenteric artery, 160, 161 Suprapubic area, 29 bladder scan and, 104 focused assessment sonography of trauma and, 39–44 still image protocol in, 47–48 videotape protocol in, 53 Suprasternal notch view in cardiac scan, 117

T Testicle scanning protocol, 195–210 anatomy and, 196 essential images in, 197 long axis view in, 198–201 inferior, 200–201 lateral or medial, 200 middle, 198–199 superior, 199–200 pathology and, 197 patient position for, 196 patient preparation in, 196 short axis view in bilateral, 205–206 inferior, 204 middle, 201–203 superior, 203

still image protocol in, 206–209 transducer for, 196 videotape protocol in, 209–210 Thoracentesis, 245–248 Thoraco-abdominal protocols, 27–118 cardiac scan and, 105–118 anatomy and, 105 apical four chamber view in, 111–112, 116 apical two chamber view in, 112, 116 essential images in, 107 parasternal long axis view in, 114 parasternal short axis view in, 110–111, 115 pathology in, 106 still image protocol in, 112–113 subxiphoid short axis view in, 118 subxiphoid/subcostal view in, 113 subxiphoid view in, 107–109 suprasternal notch view in, 117 video image protocol in, 113 focused assessment sonography of trauma and, 29–55 anatomy and, 29–30 essential and optional images in, 31 left upper quadrant scan in, 37–39 patient position in, 31 right upper quadrant scan in, 34–36 still image protocol in, 44–50 subxiphoid scan in, 32–34 suprapubic scan in, 39–44 transducer in, 31 videotape protocol in, 51–55 gallbladder ultrasound and, 57–76 anatomy in, 58 essential and optional images in, 60 long axis view in, 60–63 pathology in, 59 short axis view in, 63–66 still image protocol in, 69–73 videotape protocol in, 73–76 renal ultrasound and, 77–104 anatomy and, 77 bladder scan, short axis, 92–93 bladder scan, still image protocol, 98–99 bladder scan, videotape protocol, 103–104 essential images in, 78–79 inferior pole obscured in, 94 left kidney, long axis, 85–87 left kidney, short axis, 87–91 left kidney, still image protocol, 96–97 left kidney, videotape protocol, 102–103 obese patient and, 93 patient position in, 78 patient preparation for, 78 renal pathology and, 78 rib shadows and, 93 right kidney, long axis, 79–82 right kidney, short axis, 82–85 right kidney, still image protocol, 94–96 right kidney, videotape protocol, 100–102 Transabdominal view in first trimester scan still image protocol and, 134, 136

A03750-Index.qxd

9/8/05

1:30 PM

Page 263

Index

Transabdominal view (Cont’d) uterus long axis, 124–126 uterus on top of bladder, 134 uterus short axis, 129–130 videotape protocol and, 138–139 in ovarian scan, 147–149 sagittal, 148 transverse, 148–149 Transducer for aorta scan, 161 for cardiac scan, 106 for chest wall ultrasound for pneumothorax, 230 for common femoral vein cannulation, 242 for first trimester scan, 123 for focused assessment sonography of trauma, 31 for gallbladder ultrasound, 58 for internal jugular vein cannulation, 238 for lower extremity vascular scan, 184 for ocular scan, 212 for ovarian scan, 142 for paracentesis, 249 for pericardiocentesis, 253 for renal ultrasound, 78 for skin and soft tissue ultrasound, 222 for testicle scan, 196 for thoracentesis, 246 for ultrasound guided lumbar puncture, 234 Transverse axis view in aorta scan low, 173–175 middle, 171–172 superior, 169–170 of bladder, 40, 99, 104 in ocular scan, 212–213, 216, 218

U Ultrasound guided central line placement, 220, 237 Ultrasound guided fluid drainage, 220, 245–254 in paracentesis, 249–252 in pericardiocentesis, 252–254 in thoracentesis, 245–254 Ultrasound guided lumbar puncture, 233–236 Ultrasound mechanics, 9–26 axes and, 12–14 basic movements in, 9 fanning through image in, 16–18 initial orientation in, 10–12 pushing in probe in, 24–26 rocking of probe in, 19–21 rotating probe in, 22–23 sliding along image in, 14–16 Uterine fibroids, 123 Uterus long axis view of endovaginal, 126–128, 135, 138 transabdominal, 124–126, 134, 138 pathology of, 123 short axis view of endovaginal, 130–134, 137 transabdominal, 129–130, 136

transabdominal view, uterus on top of bladder, 134

V Vascular procedure ultrasound, 237–244 in common femoral vein cannulation, 242–244 in internal jugular vein cannulation, 237–241 Vascular protocols, 157–192 aorta scan and, 159–182 anatomy and, 159–161 aorta versus vena cava and, 176 longitudinal, low view in, 167–169 longitudinal. superior view in, 162–166 pathology and, 161 still image protocol in, 176–180 transverse, low view in, 173–175 transverse, middle view in, 171–172 transverse, superior view in, 169–170 videotape protocol in, 181–182 lower extremity scan and, 183–192 anatomy and, 183–184 common femoral artery and vein, 186–189 essential images in, 185–186 patient position for, 184 still image protocol in, 189–191 transducer for, 184 videotape protocol in, 191–192 Vena cava versus aorta, 176 Venous cannulation, 237–244 common femoral vein, 242–244 internal jugular vein, 237–241 Vesicouterine space, 30 Videotape protocol for abscess, 226 for aorta scan, 181–182 for cardiac scan, 113 for chest wall ultrasound for pneumothorax, 232 for common bile duct scan, 75–76 for common femoral vein cannulation, 244 for first trimester scan, 138–140 for focused assessment sonography of trauma, 51–55 for foreign body removal, 228 for gallbladder scan, 73–74 for internal jugular vein cannulation, 241 for ovarian scan, 155–156 for paracentesis, 252 for renal scan bladder and, 103–104 left kidney and, 102–103 right kidney and, 100–102 for skin and soft tissue ultrasound, 226–227, 228 for testicle scan, 209–210 for thoracentesis, 248 for ultrasound guided lumbar puncture, 236

263

Emergency Ultrasound: Principles and Practice

Emergency Ultrasound

Emergency Echocardiography: Principles and Practice