Focused Ultrasound Techniques for the Small Animal Practitioner E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 800

Veröffentlichungsjahr: 2013

Beschreibung

Focused Ultrasound Techniques for the Small Animal Practitioner offers a highly practical guide to incorporating abbreviated ultrasound exams into the veterinary practice. Focused point-of-care exams are an effective way to quickly detect conditions and complications not readily apparent through the physical exam, laboratory diagnostics, or radiographic findings. Encompassing all the information needed to begin performing these techniques, Focused Ultrasound Techniques for the Small Animal Practitioner is a useful tool for improving patient outcomes in clinical practice. Covering focused exams in all body systems, the book also outlines the principles of interventional radiology, medical documentation, and the basic fundamentals of using an ultrasound machine. A companion website offers 87 video clips of AFAST, TFAST, and Vet Blue examinations with normal, abnormal, and incidental findings at www.wiley.com/go/lisciandro/ultrasound. Focused Ultrasound Techniques for the Small Animal Practitioner is an essential purchase for veterinary practitioners and specialists wanting to implement these techniques in their veterinary practice.

Leseprobe

Contents

CONTRIBUTORS

ACKNOWLEDGEMENTS

INTRODUCTION TO FOCUSED ULTRASOUND FOR THE SMALL ANIMAL PRACTITIONER

Terminology

Reference

ABOUT THE COMPANION WEBSITE

CHAPTER ONE: FOCUSED—BASIC ULTRASOUND PRINCIPLES AND ARTIFACTS

Introduction

Basic Ultrasound Principles

Basic Artifacts

Basic Scanning

Deciding on an Ultrasound Machine

Image Optimization Using the Big 4 Knobs

Presets, Abdominal, Cardiac, Small Parts, etc.

Alternate Imaging Tools

On The Horizon

Recording Ultrasonographic Findings, Labeling Still Images

Ultrasound Machine and Probe Care

Setting up an Ultrasound Program

Pearls and Pitfalls, the Final Say

References

CHAPTER TWO: THE ABDOMINAL FAST3 (AFAST3) EXAM

Introduction

What AFAST3 and AFS Can Do

What AFAST3 and AFS Cannot Do

Indications for the AFAST3 and AFS Exam

Objectives of the AFAST3 and AFS Exam

How to Do an AFAST3 Exam

Naming and Order of the AFAST3 Views

AFAST3 Diaphragmatico-Hepatic View

The AFAST3 Spleno-Renal View

The AFAST3 Cysto-Colic View: The Little Fib

The AFAST3 Hepato-Renal View: The Big Lie

The AFAST3-applied Abdominal Fluid Scoring System

Use of AFAST3 and Abdominal Fluid Score in Non-Traumatic Bleeding Subsets of Patients

The Use of AFAST3 and Abdominal Fluid Score in Non-Bleeding Subsets of Patients

Use of AFAST3 and Abdominal Fluid Score in Penetrating Trauma

The Use of AFAST3 for Anaphylaxis in Dogs

The Use of AFAST3 and its DH View for Pericardial Effusions

Incidental Findings During AFAST3

Documenting AFAST3 Findings in Medical Records

Pearls and Pitfalls, the Final Say

References

CHAPTER THREE: FOCUSED OR COAST3—LIVER AND GALLBLADDER

Introduction

What the Focused Liver and Gallbladder Exam Can Do

What the Focused Liver and Gallbladder Exam Cannot Do

Indications for the Focused Liver and Gallbladder Exam

Objectives of the Focused Liver and Gallbladder Exam

Ultrasound Settings and Positioning

How to Do the Focused Liver and Gallbladder Exam

Ultrasonographic Findings in a Normal Focused Liver and Gallbladder Exam

Clinical Significance and Implications of Abnormal Focused Liver and Gallbladder Findings

The Routine Add-on of AFAST3 and its Abdominal Fluid Scoring System

Pearls and Pitfalls, the Final Say

References

CHAPTER FOUR: FOCUSED OR COAST3—SPLEEN

Introduction

What the Focused Spleen Exam Can Do

What the Focused Spleen Exam Cannot Do

Indications for the Focused Spleen Exam

Objectives of the Focused Spleen Exam

Patient Positioning and Probe Selection

How to Do the Focused Spleen Exam

Ultrasonographic Findings in a Normal Spleen

Clinical Significance and Implications of Abnormal Findings

The Routine Add-on of AFAST3 and its Abdominal Fluid Scoring System

Pearls and Pitfalls, the Final Say

References

CHAPTER FIVE: FOCUSED OR COAST3—KIDNEYS

Introduction

What the Focused Kidney Exam Can Do

What the Focused Kidney Exam Cannot Do

Indications for the Focused Kidney Exam

Objectives of the Focused Kidney Exam

Patient Positioning and Probe Selection

Patient Preparation

How to Do the Focused Kidney Exam

Ultrasonographic Findings in a Normal Kidney

Clinical Significance and Implications of Abnormal Kidney Findings

The Addition of the Focused Urinary Bladder Exam

The Routine Add-on of AFAST3 and its Abdominal Fluid Scoring System

Pearls and Pitfalls, the Final Say

References

CHAPTER SIX: FOCUSED OR COAST3—URINARY BLADDER

Introduction

What the Focused Urinary Bladder Exam Can Do

What the Focused Urinary Bladder Exam Cannot Do

Indications for the Focused Urinary Bladder Exam

Objectives of the Focused Urinary Bladder Exam

Patient Positioning and Probe Selection

How to Do the Focused Urinary Bladder Exam

Ultrasonographic Findings in a Normal Urinary Bladder

Artifacts Associated with the Focused Urinary Bladder Exam

Clinical Significance and Implications of Abnormal Urinary Bladder Findings

The Addition of the Focused Kidney Exam

The Routine Add-on of AFAST3 and its Abdominal Fluid Scoring System

Pearls and Pitfalls, the Final Say

References

CHAPTER SEVEN: FOCUSED OR COAST3—GASTROINTESTINAL AND PANCREAS

Introduction

What a Focused Gastrointestinal Tract and Pancreas Exam Can Do

What a Focused Gastrointestinal Tract and Pancreas Exam Cannot Do

Indications for the Focused Gastrointestinal Tract and Pancreas Exam

Objectives of the Focused Gastrointestinal Tract and Pancreas Exam

Patient Positioning and Probe Selection

Scanning Technique

Focused Gastrointestinal Tract and Pancreas Findings and their Significance

Pearls and Pitfalls, the Final Say

References

CHAPTER EIGHT: FOCUSED OR COAST3—REPRODUCTIVE

Introduction

What the Focused Reproductive Exam Can Do

What the Focused Reproductive Exam Cannot Do

Indications for Focused Reproductive Exam

Objectives of the Focused Reproductive Exam

Reproductive Conditions of the Female

Patient Positioning and Probe Selection for the Female

Imaging the Normal Uterus

Dystocia

Cystic Endometrial Hyperplasia—Pyometra Complex

Reproductive Conditions of the Male

Pearls and Pitfalls, the Final Say

References

CHAPTER NINE: THE THORACIC FAST3 (TFAST3) EXAM

Introduction

What TFAST3 Can Do

What TFAST3 Cannot Do

Indications for the TFAST3 Exam

Objectives of the TFAST3 Exam

Ultrasound Settings and Probe Preferences

How to Do a TFAST3 Exam

Performing the TFAST3 Exam

Performing the TFAST3 Chest Tube Site Part of the Exam

Findings at the TFAST3 Chest Tube Site View

Diagnosis of Pneumothorax

The Search for the “Lung Point” and the Degree of Pneumothorax Historically

The Wet Lung vs. Dry Lung Concept

The Presence of Subcutaneous Emphysema and TFAST3 Imaging

Performing the TFAST3 Pericardial Part of the Exam

Performing the TFAST3 Diaphragmatico-Hepatic (DH) Fifth View

Findings at the TFAST3 Pericardial Site View

Determining Pleural from Pericardial Effusion

Determining the Presence of Cardiac Tamponade

The Use of the Diaphragmatico-Hepatic View for Pericardial Effusions

Characterization of Pleural and Pericardial Effusions

The Use of the Diaphragmatico-Hepatic View for Types of Diaphragmatic Herniation

Determining Volume Status and Contractility by the Left Ventricular Short-Axis View

The Use of M-mode for Lung Ultrasound

TFAST3 Revised to Now Include the Vet BLUE Lung Scan

TFAST3 Summary of Views and their Clinical Utility

Documenting TFAST3 Findings in Medical Records

Pearls and Pitfalls, the Final Say

References

CHAPTER TEN: THE VET BLUE LUNG SCAN

Introduction

What Vet BLUE Can Do

What Vet BLUE Cannot Do

Indications for the Vet BLUE Exam

Objectives of the Vet BLUE Exam

Ultrasound Settings and Probe Preferences

How to do a Vet BLUE Exam

Performing the Vet BLUE

Lung Ultrasound Findings: Dry Lung, Wet Lung, Shred Sign, Tissue Sign, and Nodule(s) Sign

Pneumothorax, A-lines Without a Glide Sign

Recording Vet BLUE Findings

Case-Based Vet BLUE Patterns and Their Clinical Relevance

Dry Lung vs. Wet Lung Concept and Basic Lung Ultrasound Signs and Differentials

The Clinical Relevance of Vet BLUE and Left-Sided Heart Failure and Volume Overload

The Use of M-mode and Power Doppler for Lung Ultrasound

The Future of Lung Ultrasound in Small Animals

Pearls and Pitfalls, the Final Say

References

CHAPTER ELEVEN: FOCUSED OR COAST3—ECHO (HEART)

Introduction

What Focused ECHO Can Do

What Focused ECHO Cannot Do

Indications for the Focused ECHO Exam

Objectives of the Focused ECHO Exam

Ultrasound Settings and Probe Preferences

How to do a Focused ECHO Exam

Performing the Focused ECHO Exam and the Three Main ECHO Windows

Focused ECHO Findings in Common Cardiac Diseases

Pearls, Pitfalls, the Final Say

References

CHAPTER TWELVE: FOCUSED OR COAST3—CENTRAL VENOUS AND ARTERIAL LINE PLACEMENT, BIG ARTERIES, AND VEINS

Introduction

What the Focused Central Venous and Arterial Line Placement, Big Arteries, and Veins Can Do

What the Focused Central Venous and Arterial Line Placement, Big Arteries, and Veins Cannot Do

Indications for Focused Central Venous and Arterial Line Placement, Big Arteries, and Veins

Objectives for Focused Central Venous and Arterial Line Placement, Big Arteries, and Veins

Placement of an US-Guided Central Venous Jugular Catheter (CVC)

How to Place an US-guided Central Venous Jugular Catheter

Placement of Ultrasound-Guided Femoral Arterial Catheters and Sampling

How to Place an Ultrasound-Guided Femoral Arterial Catheter or Obtain an US-Guided Femoral Artery Sample

General Comments Regarding Transverse vs. Longitudinal Orientation

Arterial Thromboembolism and Deep Venous Thrombosis

Pearls and Pitfalls, the Final Say

References

CHAPTER THIRTEEN: FOCUSED OR COAST3—PEDIATRICS

Introduction

What Focused Pediatrics Can Do

What Focused Pediatrics Cannot Do

Indications for Focused Pediatrics Exam

Objectives for Focused Pediatrics Exam

Equipment

Patient Preparation

Ultrasound of the Normal Pediatric Abdomen

Common Pediatric Abdominal Disorders

Metabolic Conditions of the Pediatric Patient

Genitourinary Disorders

Pearls and Pitfalls, the Final Say

References

CHAPTER FOURTEEN: FOCUSED OR COAST3—EYE

Introduction

What the Focused Eye Exam Can Do

What the Focused Eye Exam Cannot Do

Indications for the Focused Eye Exam

Objectives of the Focused Eye Exam

Ultrasound Settings

Patient Eye Preparation

How to Do the Focused Eye Exam

Ultrasonographic Findings in a Normal Eye

Clinical Significance and Implications of Abnormal Findings

Pearls and Pitfalls, the Final Say

References

CHAPTER FIFTEEN: FOCUSED OR COAST3—MUSCULOSKELETAL

Introduction

What the Focused Musculoskeletal Exam Can Do

What the Focused Musculoskeletal Exam Cannot Do

Indications for the Focused Musculoskeletal Exam

Objectives of the Focused Musculoskeletal Exam

Patient Positioning and Probe Selection

How to Do the Focused Musculoskeletal Exam

Ultrasonographic Normal Findings in a Focused Musculoskeletal Exam

Clinical Significance and Implications of Abnormal Findings

Pearls and Pitfalls, the Final Say:

References

CHAPTER SIXTEEN: FOCUSED OR COAST3—CARDIOPULMONARY RESUSCITATION (CPR), GLOBAL FAST (GFAST3), AND THE FAST-ABCDE EXAM

Introduction

What the Focused CPR (GFAST3) and the FAST-ABCDE Can Do

What the Focused CPR (GFAST3) and the FAST-ABCDE Cannot Do

Indications for Focused CPR (GFAST3) and the FAST-ABCDE Exam

Objectives of the Focused CPR (GFAST3) and the FAST-ABCDE Exam

Ultrasound Settings, Probe Preferences, and Patient Positioning

How to do the Focused CPR and the FAST-ABCDE Exam

Clinical Significance and Implications of Abnormal Focused CPR (GFAST3) and FAST-ABCDE Exam Findings

Pearls and Pitfalls, the Final Say

References

CHAPTER SEVENTEEN: INTERVENTIONAL ULTRASOUND-GUIDED PROCEDURES

Introduction

Pericardiocentesis

Thoracocentesis

Abdominocentesis

Modified Ultrasound-Guided Diagnostic Peritoneal Lavage (MUG-DPL)

Pearls and Pitfalls, the Final Say

References

APPENDIX I SETTING UP AN ULTRASOUND PROGRAM

Introduction

APPENDIX II GOAL-DIRECTED TEMPLATES FOR MEDICAL RECORDS

Abdominal Focused Assessment with Sonography for Trauma, Triage, and Tracking (AFAST3)

Chapter 3: Focused or Cageside (COAST3)–Liver and Gallbladder

Chapter 4: Focused or Cageside (COAST3)—Spleen

Chapter 5: Focused or Cageside (COAST3)—Kidney

Chapter 6: Focused or Cageside (COAST3)—Urinary Bladder

Chapter 7: Focused or Cageside (COAST3)–Gastrointestinal and Pancreas

Chapter 8: Focused or Cageside (COAST3)—Reproductive

Chapter 9: Thoracic FAST3 (TFAST3)

Chapter 10: The Vet Blue Lung Scan (VBLS or Vet Blue)

Chapter 11: Focused or Cageside (COAST3)—Echo (Heart)

Chapter 13: Focused or Cageside (COAST3)—Pediatrics

Chapter 14: Focused or Cageside (COAST3)—Eye

Chapter 16: Focused CPR—Global FAST3 (GFAST3) and FAST-ABCDE

APPENDIX III ABBREVIATIONS, TERMINOLOGY, AND GLOSSARY

Abbreviations

Terminology and Glossary

APPENDIX IV QUICK REFERENCES OF NORMAL VALUES AND RULES OF THUMB

Chapter 2: Abdominal FAST3 (AFAST3)

Chapter 3: Focused or Cageside (COAST3)—Liver and Gallbladder

Chapter 4: Focused or Cageside (COAST3)—Spleen

Chapter 5: Focused or Cageside (COAST3)—Kidney

Chapter 6: Focused or Cageside (COAST3)—Urinary Bladder

Chapter 7: Focused or Cageside (COAST3)— Gastrointestinal and Pancreas

Chapter 8: Focused or Cageside (COAST3)—Reproductive

Chapter 9: Thoracic FAST3 (TFAST3)

Chapter 10: Vet BLUE

Chapter 11: Focused or Cageside (COAST3)—ECHO (Heart)

Chapter 13: Focused or Cageside (COAST3)—Pediatrics

Chapter 16: Focused or COAST3—CPR and the FAST-ABCDE Exam

Reference

APPENDIX V ULTRASOUND RESOURCES AND COMPANIES

Online Resources for Ultrasound Training

Online Access to the General Practitioner Ultrasound Group

Veterinary Ultrasound Companies

Index

This edition first published 2014 © 2014 by John Wiley & Sons, Inc

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Library of Congress Cataloging-in-Publication Data

Focused ultrasound techniques for the small animal practitioner / edited by Gregory R. Lisciandro.        p. cm.    Includes bibliographical references and index.

    ISBN 978-1-118-36959-3 (cloth : alk. paper) – ISBN 978-1-118-40388-4 (epdf) – ISBN 978-1-118-40389-1 (epub) – ISBN 978-1-118-40390-7 (emobi) – ISBN 978-1-118-76077-2 1. Veterinary ultrasonography. I. Lisciandro, Gregory R., editor of compilation.    [DNLM: 1. Ultrasonography–methods. 2. Ultrasonography–veterinary. 3. Animal Diseases–ultrasonography. 4. Pets. 5. Veterinary Medicine–methods. SF 772.58]    SF772.58.F63 2013    636.089′607543–dc23

2013026487

A catalogue record for this book is available from the British Library.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Cover image: top left image and bottom left image © Alice MacGregor Harvey, Medical Illustrator, North Carolina State College of Veterinary Medicine.

Cover design by Matt Kuhns

DEDICATION

To my grandparents Sam and Bernice Long and John and Mary Lisciandro; my parents Richard and Judy and siblings Denise, Kim, Kelly, and John; and most especially my lovely wife Stephanie and our children Noah, Hannah, Sarah, and Joshua for their patience, encouragement, and inspiration; and lastly the good Lord for making the textbook and all its many variables miraculously fall in place to its completion.

CONTRIBUTORS

Andrea Armenise, DVMWINFOCUS Veterinary Care Section Coordinatorwww.winfocus.orgOspedale Veterinario Santa FaraBari, Italy

Tomas W. Baker, MSDepartment of Surgery and Radiological SciencesSchool of Veterinary MedicineUniversity of CaliforniaDavis, California

Søren Boysen, DVM, Dipl. ACVECCAssociate Professor, Faculty of Veterinary MedicineDepartment of Veterinary Clinical and Diagnostic SciencesUniversity of CalgaryCalgary, Canada

Scott Chamberlin, DVM Resident, Emergency and Critical CareCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort Collins, Colorado

Jane Cho, DVM, Dipl. ACVOVeterinary Eye Specialists, PLLCArdsley, New York

Autumn P. Davidson DVM, MS, Dipl. ACVIMDepartment of Medicine and EpidemiologySchool of Veterinary MedicineUniversity of CaliforniaDavis, California

Teresa DeFrancesco, DVM, Dipl. ACVECC, Dipl. ACVIM (Cardiology)Professor, College of Veterinary MedicineNorth Carolina State UniversityRaleigh, North Carolina

Robert M. Fulton, DVMResident, TheriogenologyBetty Baugh’s Animal ClinicRichmond, Virginia

Jennifer Gambino, DVMClinical InstructorDepartment of Diagnostic Imaging, Animal Health CenterMississippi State University College of Veterinary MedicineStarkville, Mississippi

Gregory R. Lisciandro, DVM, Dipl. ABVP, Dipl. ACVECCConsultant, Hill Country Veterinary SpecialistsChief of Emergency Medicine and Critical Care, Emergency Pet Center, Inc.San Antonio, [email protected]

Stephanie Lisciandro, DVM, Dipl. ACVIMConsultant, Hill Country Veterinary SpecialistsStaff Internist, Mission Veterinary SpecialistsSan Antonio, Texas

Sarah Young, DVMMobile UltrasonographerEcho Service for PetsOjai, California

ACKNOWLEDGEMENTS

Words cannot express my eternal gratitude to Drs. Mike Lagutchik, Kelly Mann, Geoffrey Fosgate, and Andra Voges for their efforts; doctors; technicians; Mr. Adrian Ford and Dr. Tom Hanna of the Emergency Pet Center, Inc., for enthusiastically helping complete novel clinical research in a private practice setting; and Robert Whitaker, who believed in the abbreviated ultrasound format and gave me a beginning in training veterinarians in these focused assessment with sonography for trauma (FAST) techniques.

The following individuals made significant contributions to the textbook: Nancy Place, MS, Association of Medical Illustrators, who provided much of the illustrative artwork in the Abdominal FAST, Thoracic FAST, and Vet BLUE chapters; Alice MacGregor Harvey, medical illustrator, North Carolina State College of Veterinary Medicine, who provided the illustrative artwork in Chapter 11; Dr. Maria Hey, who formatted and arranged all of the book’s images; Dr. Jennifer Gambino, who additionally helped with editing chapters 3 and 5; Dr. Sarah Young, who provided many of the excellent ultrasound images and reviewed portions of the manuscript; Guy Hammond of Veterinary Imaging, for ultrasound machine/equipment support and his leadership in creating the General Practice Ultrasound Group (GPUS) made up of Drs. John Mattoon, Marti Moon, Sarah Young, Ron Kelpe and myself; Dr. Warren “Sherm” Mathey who read nearly the entire manuscript; Dr. Søren Boysen, for his tireless support, encouragement, and constructive criticism from the very beginning of our FAST start in 2005; Erica Judisch, Susan Engelken, and the entire Wiley Blackwell team for their patience and support; and Dr. Stephanie Lisciandro for her additional time and efforts in the editing process.

Finally, thank you to each of the chapter authors, Andrea Armenise, Tomas Baker, Søren Boysen, Jane Cho, Scott Chamberlin, Autumn Davidson, Teresa DeFrancesco, Robert Fulton, Jennifer Gambino, and Stephanie Lisciandro, who not only believe in the potential for abbreviated ultrasound exams to make a significant positive impact on veterinary medicine, but who also generously gave their time and expertise in making this project possible. To them, I am forever grateful.

INTRODUCTION TO FOCUSED ULTRASOUND FOR THE SMALL ANIMAL PRACTITIONER

Gregory R. Lisciandro

The translational study from the human to the veterinary patient regarding the focused assessment with sonography for trauma (FAST) exam by Dr. Søren Boysen in 2004 has opened the veterinary imaging world’s eyes to legitimate non-radiologist use of abbreviated ultrasound exams. Such exams are of utmost importance because they are safe (no radiation) and non-invasive, allowing point-of-care evaluation of short-duration with limited patient restraint. These ultrasound interrogations also carry the potential to answer clinically important questions that remain enigmatic by using traditional means of physical examination, laboratory findings, and radiographic imaging. Moreover, by using abbreviated ultrasound exams, patients have the potential to survive because traditionally occult life-threatening disease was historically missed without using ultrasound. By using abbreviated ultrasound exams, disease may be detected on our terms rather than the disease’s in the midst of traditionally less sensitive means, and the delay of scheduling formal or complete ultrasound exams or other advanced imaging studies is avoided. In human medicine, the so-called turf wars between who should and should not be conducting ultrasound studies has been somewhat mitigated by the realistic impression that abbreviated exams not only detect disease in a more timely manner, but also keep patients alive by better directing care. As more patients survive, the need for formal or complete ultrasound studies or other advanced imaging techniques increases. In other words, the human and veterinary radiologist to the contrary may become even busier.

The readers of this text should review the following sections to optimize the didactic potential of our textbook. We welcome feedback ([e-mail]; www.fastvet.com) from your experiences as general practitioners and emergency and critical care veterinarians on the front lines of veterinary medicine.

Terminology

For a grasp of some of the concepts described below and throughout the subsequent chapters, let’s define a few things.

The Abbreviated Ultrasound Exam

With the sudden eruption of bedside ultrasound exams by non-radiologists in human medicine, terminology has become convoluted, but generally the term “bedside” seems to be winning out. For example, a bedside gallbladder exam will be called just that, with its objectives being to answer simple clinical questions to help expediently guide the clinical course and to trigger the possible need for more formal (or complete) ultrasound examinations or other advanced imaging. On the other hand, the veterinary bedside lung ultrasound exam (called Vet BLUE) is similarly performed, however, it has been given an acronym. For clarity and to prevent an onslaught of terminology in veterinary medicine, we will use a limited number of terms.

Abbreviated ultrasound exams may be termed either “focused X” or “focused Y” exams, as suggested by the General Practitioner’s Ultrasound Group (GPUS Group, www.gpultrasound.org) (see Appendix V for Internet access to the document). Such exams also may be referred to analogously as in the human literature, replacing “bedside” with “cageside.” Thus, a “cageside organ assessments for trauma, triage, and tracking” may be turned into the acronym “COAST3” and similarly used as a “COAST3 X” or “COAST3 Y” exam with the “T3” standing for trauma, triage, and tracking (monitoring) subsets of veterinary patients. The “T3” has been previously proposed in the veterinary literature regarding the use abdominal FAST (AFAST) and thoracic FAST (TFAST) exams (Lisciandro 2011). Thus, the terms AFAST3 and TFAST3 seem best suited for use in many non-trauma subsets of veterinary patients for triage and tracking.

Importantly, the standardization of veterinary terminology gives absolute clarity among colleagues as to the exact exam format being performed. The accepted use of these veterinary terms has been previously proposed for preventing an onslaught of terms in veterinary medicine (avoiding what has occurred in human medicine) (Lisciandro 2011).

The terminology for radiologist-performed exams in human medicine has generally taken on the term “formal” abdominal ultrasound or “formal” echocardiography. The use of “diagnostic” is not adequate and should be discouraged in veterinary medicine because any abbreviated ultrasound exam format may be “diagnostic.” Rather than use the term “formal,” consistent with human terminology, we use the term “complete,” as suggested by the GPUS Group. Thus, the terminology for veterinarians is as follows for the abdominal cavity and thorax, respectively: “complete abdominal ultrasound” and “complete echocardiography.”

Recording Findings of the Focused, COAST3 and FAST3 Exams

The authors of this textbook acknowledge that each of these abbreviated ultrasound exams will evolve over time as to the diagnostic abilities in terms of their sensitivity, specificity, and accuracy. At this time, the best way to study results seems to be through template, goal-driven, formatted entries for medical records. In a bold attempt, by using both our experiences and those of the GPUS Group, such examples have been listed in the Appendices (Appendix II) and should be reviewed (and we encourage their use) by our readers.

Echogenicity: The Whites, Grays, and Blacks of Ultrasound

The jargon of ultrasound can be intimidating to the novice non-radiologist ultrasonographer. Clarity may be accomplished through acknowledging that ultrasound is the opposite of what tissues appear as on radiographic studies (our brain needs to reformat itself). For example, and very simplistically, air is white on ultrasound and black on radiographs. Bone is black (shadows) on ultrasound and white on radiographs. The ultrasound terms describing whites, grays, and blacks are referred to as hyperechoic, hypoechoic, and anechoic, with the terms “relative to X” and “relative to Y” used to further describe ultrasound imaging when detail is somewhere in between (Figure 1). For example, the spleen is hyperechoic (brighter ) when compared to the left kidney. A few definitions:

Figure 1.Illustration of degrees of echogenicity, ranging from anechoic (darkest [black]) to hyperechoic (lightest [white]).

Anechoic (pure black): Occurs when no ultrasound waves are reflected back to the receiver. Thus, normal urine, normal bile, transudates, and blood all are purely anechoic (black).

Hypoechoic (shades of gray): Occurs when variable degrees of the ultrasound waves are reflected back to the receiver. Thus, all soft tissues that are not fully aerated are described relative to other distinct tissues; for example, the liver is hypoechoic (darker than) relative to the spleen.

Hyperechoic (whites, bright whites): Occurs when all or nearly 100% of ultrasound waves are reflected back to the receiver. Thus, bone, stone (metals), and air are strong reflectors, resulting in hyperechoic interfaces with either shadowing, comet-tail artifacts, ultrasound lung rockets, or reverberation artifact projected distally.

Isoechoic (same echogenicity): Occurs when tissues are the same shades of gray. For example, if the liver is isoechoic to the spleen, then they are the same echogenicity (same shades of gray).

Directional Terms for Orientation

Longitudinal and sagittal: The term longitudinal refers to orientation parallel to the spine or long-axis of the patient’s body. The term sagittal refers to the longitudinal axis of the respective deeper structure being evaluated. For example, the superficial jugular vein is imaged in longitudinal, whereas the deeply located right kidney (angled and not parallel to the body’s long-axis) is imaged in sagittal planes (parallel to the right kidney’s long-axis). The terms are often used interchangeably (or arguably misused); however, by appreciating that both terms are in their own right long-axis views, directional communication between veterinarians seems to be clear by use of either term. The probe marker is directed toward the patient’s head.

Transverse: The term transverse refers to orientation 90 degrees to the long-axis of the structure being evaluated. The probe marker is turned to the left (or counterclockwise) to the patient’s right side (if in dorsal recumbency or right lateral recumbency).

With that said, let’s get on with Chapter 1. And remember, focused and FAST3 saves lives.

Reference

Lisciandro GR. 2011. Abdominal and thoracic focused assessment with sonography for trauma, triage, and monitoring in small animals. J Vet Emerg Crit Care 21(2):104–122.

ABOUT THE COMPANION WEBSITE

This book is accompanied by a companion website:

www.wiley.com/go/lisciandro/ultrasound

The website includes a video bank containing more than 80 videos.

CHAPTER ONE

FOCUSED—BASIC ULTRASOUND PRINCIPLES AND ARTIFACTS

Robert M. Fulton

Introduction

Turn on the machine. Apply coupling gel. Start scanning. In the realm of the busy veterinary general practice, emergency clinic, or intensive care unit, that statement really sums up the basic use of ultrasound. Just as natural as it is for us to take the stethoscope from around our neck and place it on a patient’s thorax, so should be picking up the ultrasound probe and placing it on the patient. No wonder that ultrasonography has been appropriately dubbed both “an extension of the physical exam” and the “modern stethoscope” (Rozycki 2001; Filly 1988). Really, one doesn’t need a whole lot of instruction to start scanning; however, as for a lot of things in life, the devil is in the details. Proper imaging technique and understanding its limitations are the keys to accurate image interpretation of diagnostic ultrasound.

The focus of this chapter is a fairly brief review of the basic physics and principles of ultrasound including the more common problematic artifacts. For interested readers, there are more comprehensive textbooks dedicated to the physics and interpretation of ultrasound imaging (Nyland 2002; Penninck 2002).

What Focused Basic Ultrasound Principles and Artifacts Can Do

Provide a basic review of ultrasound physics, image formation, common artifacts, and ultrasound systematics

Provide a basic understanding of how artifacts are formed to allow better interpretation of the ultrasound image

What Focused Basic Ultrasound Principles and Artifacts Cannot Do

Cannot provide an in-depth discussion of ultrasound physics, principles, and artifacts

Indications

Provide a basic understanding of ultrasound physics, principles, and artifacts for the non-radiologist veterinarian

Objectives

Provide an understanding of the basic fundamentals of ultrasound physics and how they relate to image formation

Provide an understanding of how basic ultrasound artifacts are formed to avoid misinterpretation

Provide a review of basic ultrasound systematics including image orientation and storage and machine and probe care

Basic Ultrasound Principles

The ultrasound (US) machine consists of two main parts, the probe and the processor. The probe is the “brawn” and the processor the “brains” of the operation. The probe has two main functions: first, to generate a sound wave (acts as a transmitter); second, to receive a reflected sound wave (acts as a receiver). The processor, located within the mainframe, takes these incoming signals and turns them into a useful image.

The transmitter and receiver functions of the transducer do not occur simultaneously, but rather sequentially. When placed under mechanical stress the ceramic crystals in the transducer generate a voltage. This process, known as the piezoelectric effect, occurs during the receiving phase, which is when returning sound waves strike the transducer. When an external voltage is applied to the crystals they exhibit the reverse phenomenon and undergo a small mechanical deformation. The subsequent release of this energy generates the ultrasound wave. This is known as the reverse piezoelectric effect. World War I saw the first practical use of the piezoelectric effect in the development of sonar using a separate sound generator and detectors (Coltera 2010).