vision is the art of seeing what is basic invisible to

BASIC ABDOMINAL ULTRASOUND

• “VISION IS THE ART OF SEEING WHAT IS

INVISIBLE TO OTHERS.”- JONATHON SWIFT

• AMY BOSSUNG DVM, IVUSS CERT

• MOBILE SONOGRAPHER

MY EXPERIENCE - HOW I STARTED

• Small Animal Practitioner for 21 years

• Ultrasound was in it’s beginnings

• Fortunate to have an employer/mentor

• Started with a used machine

• Went to my first seminar – 3 people

• Started scanning

• Radiologist reviews of exams -VHS

BLAST FROM THE PAST

• Eventually we upgraded machine

• Continued to take advantage of education

packages with each upgrade

• Read everything I could

• Put the probe on anything I could.

MY EXPERIENCE – HOW I STARTED

• Started scanning in 1995.

• In 2006 expanded to mobile ultrasound work by starting

Animage, Inc to meet a growing need in the area.

• Completed IVUSS Certification program in 2010.

• IVUSS – International Veterinary Ultrasound Society -

Website IVUSS.org

• Today I work part time in general practice and part time

performing mobile ultrasound exams for local veterinarians.

REFERENCES/RESOURCES

• Nyland and Matton

• Penninck and d’Anjou

• Sonopath.com

• VIN

• ACVR Ultrasound Society

• Journal - Veterinary Radiology and

Ultrasound

• Conference Notes

A GROWING FIELD

“Today, ultrasonography is an

integral part of the

diagnostic approach in

academic institutions as well

as in private practice.”- Atlas

of Small Animal

Ultrasonography,Penninck/d'

Anjou

BASIC PRINCIPLES OF SOUND

Diagnostic ultrasound is the use of high frequency sound waves to produce an image from within the

body.

Diagnostic sound waves are above the range of

human hearing.

Audible sound - < 0.2 mHz

Ultrasound waves - 2-10 mHz (10-100 x more)

Human hearing has a limited range of 20 Hz to

20 kilohertz (kHz). Ultrasound is

considered those frequencies greater than 20 kHz, while diagnostic

ultrasound utilizes frequencies greater than 1

megahertz (MHz).


• Sound energy is a form of

mechanical energy that travels

in a longitudinal wave in cycles

of compressions and

rarefactions.

• Sound transmission requires

medium such as air, liquid or

tissue.

• Each wave has a wavelength,

speed of travel and frequency.


• A cycle is the time required for one

complete compression and rarefaction

• Frequency is the # of cycles per second

• Frequency measured in Hertz where 1

Hz = 1 cycle/sec

• Wavelength is distance in millimeters

that the sound wave travels in one

cycle

BASIC PRINCIPLES OF ULTRASOUND

• Speed of sound depends on the density and stiffness of the

medium through which it travels.


• Speed of travel of sound in

soft tissue is fairly constant

value at 1540 m/s which

means wavelength and

frequency are inversely

related.

• As such the higher the

frequency of the sound

waves produced the

shorter the wavelength.

• Higher frequencies =

shorter wavelengths

• Lower frequency = longer

wavelengths


Velocity of sound is independent of frequency and does not change through a homogenous structure.

Sound travels at the same speed (1540 m/s) through soft tissue whether you use a 2.0 mHz or 10 mHz probe

Velocity is calibrated into the machine which calculates the distance to the imaged structure based on how long it takes to receive reflected echos.


• Acoustic Impedance – opposition or resistance to the flow of sound

through a medium


• The difference in acoustic impedance

between tissues is important.

• The greater the difference between

acoustic impedance between adjacent

tissues the greater the reflection of sound

waves at the interface.

• If there is no acoustical impedance

difference between adjacent tissues (i.e.

they have the same acoustical impedance)

their boundary will not produce an echo

and the tissue will appear the same. (Ex

liver lobes)


• Though it sounds contradictory the higher the density and

greater the velocity of sound through a medium the greater

the resistance to sound transmission

• Example bone: Speed of sound through bone is 4080 m/s

but it has a high density (inability to compress and rarefact)

and therefore has a high acoustical impedance and a high

degree of sound reflection thus creating a shadow.


• In contrast air has a low speed of sound (330 m/sec) and a

low impedance. However there is 99% reflection of sound

at soft tissue-air interfaces

• Why? Reflection of sound depends on an acoustical

mismatch. The greater the difference in acoustical

properties the greater the reflection.

• This is why you need coupling gel between the transducer

and skin and why you cannot image aerated lungs.

BASIC PRINCIPLES OF SOUND-TISSUE INTERACTION/IMAGE PRODUCTION

• Basis of ultrasound imaging is sound waves are generated

and travel through tissue.

• The interaction of the sound with the tissues determines

what we see on the screen.

• The sound waves as they travel through tissue undergo

either reflection, refraction or absorption.

• The reflected waves that return to the probe are

responsible for the image.

REFLECTION

• Responsible for the image

• Depends on the acoustical

mismatch (ie bone-soft tissue and

air-soft tissue interface)

• Depends on angle of incidence

(sound striking perpendicular will

have more sound reflected back

to the transducer)

• Depends on the reflecting

structures size (higher frequency

transducers can reflect sound

from smaller structures)

Structures that are small and

irregular with respect to the

sound wave cause scatter of

the sound

REFRACTION

• Change in direction of

sound as it travels from

one medium to another

where the speed of travel

is different.

• Usually occurs where

there is a fluid filled or

rounded structure such as

the gall bladder or kidney.

REFRACTION

ABSORPTION

ABSORPTION

• Sound waves that are absorbed by

the tissue and converted to heat by

frictional forces in the tissue.

ATTENUATION

• Decrease in the intensity or

loss of energy of the

ultrasound beam due to

absorption, reflection,

refraction and scatter

• High frequency sounds

attenuate to a higher degree

thus have less energy for

deeper structures to reflect

GENERATING THE IMAGE

• Machine

-Holds the computer and amplifier

• Transducer

-pizoelectric crystals in special housing,

connects to the machine with cable

• Monitor screen

-displays the image

GENERATING THE IMAGE

• Transducer (Probe)

• Pizoelectric crystals within

transducer converts electrical

energy into sound energy

• Multi frequency – 5-8 or 3-8 mHz

most common

• Voltage applied intermittently so

crystals produce sound 1% of time

and 99% is spent receiving echos

TRANSDUCER TYPES

• Linear array

• -rectangular image

• -usually higher frequency 7.5-12

mHz

• -used for superficial structures

that need higher resolution

• -feline abdomen, thyroid glands

TRANSDUCER TYPES

• Sector probes

-curvilinear

-pie shape image

-multifrequency

-most commonly used;

work horse

• Phased array probe

-used in cardiac imaging

SECTOR PROBES

REMEMBER

TRANSDUCER FREQUENCY RELATION

HIGHER FREQUENCY=INCREASED RESOLUTION

AND DECREASED DEPTH

LOWER FREQUENCY=DECREASED RESOLUTION

AND INCREASED DEPTH

HIGH RES LOW DEPTH

LOW RES MORE DEPTH

RESOLUTION

• Spatial Resolution

–ability to distinguish two points as separate in space.

- sub categorized to axial and lateral

• Axial resolution – ability to differentiate two points along

the length of the beam

-improves image quality and detail

-higher frequency probes have better axial resolution

RESOLUTION

• Lateral Resolution

-ability to differentiate

two points lying side by

side perpendicular to the

sound beam

-higher frequencies have

higher lateral resolution

-best at the focal zone

ULTRASOUND MODES

• B mode (Brightness Mode)

-uses principle that each

returning echo is displayed on

the screen as a dot

-brighter the dot the higher the

intensity of the returning echoes

-real time ultrasound

uses this mode and

still images

ULTRASOUND MODES

• M mode (Motion mode)

-single ultrasound beam in a fixed position and records

how the dimensions of the section being interrogated

change with time

-used with cardiac

imaging

VOCABULARY

• Normal relative echogenicity of organs

Spleen Most hyperechoic

Liver

Renal Cortex

Renal Medulla Least hypoechoic

VOCABULARY -ARTIFACTS

• Acoustic Shadow – most

common with bone,

calcification and gas

-structures reflect and/or

absorb about 100% of

ultrasound beam

-dark area distal to structure

(anechoic-black)

- see most commonly with rib

shadows; skin air interface

ACOUSTIC SHADOW

BLADDER CALCULI

VOCABULARY - ARTIFACTS

• Acoustic Enhancement (through transmission)

-hyperechoic (bright area) distal to a structure that has

lower attenuation than the surrounding structure

-most common with cysts and gall bladder or fluid filled

viscus

ACOUSTIC ENHANCEMENT

GALL BLADDER


• Reverberation

-reflection of ultrasound beam back and forth between two reflective

surfaces

-most common with lung wall interfaces, GI gas, metallic foreign bodies

-comet tail or ring down is special form of reverberation. Seen with gas

bubbles intestines or in lungs

REVERBERATION


• Mirror image artifact

-illusion of a duplicate image on the other side of a reflective

surface

-caused by altered echoes

- that are “late” returning to the transducer

-transducer interprets these as coming from a deeper area

because the echoes take longer to return

-most common with liver at diaphragm (looks like liver is in

the thorax)

MIRROR IMAGE ARTIFACT

MIRROR IMAGE ARTIFACT EXAMPLE

VOCABULARY ARTIFACTS

• Side lobe artifact

-causes anatomy outside the main beam to show up as if

in the main beam

-a highly reflective surface outside the main beam can

result in echoes returning to the transducer

-slice thickness or grating is another type of this artifact

-common with gall bladder or urinary bladder, mimics

sediment or colon looks like it is in the bladder

SIDE LOBE AND SLICE THICKNESS

VOCABULARY ARTIFACTS

• Refraction

-bending of sound beam

along margin of rounded

organ or structure

-common with kidney

edge of kidney or gall

bladder

REFRACTION

DOPPLER

• color flow Doppler ultrasound - a form of pulse wave

Doppler in which the energy of the returning echoes is

displayed as an assigned color.

Red=towards probe; Blue=away from probe

• continuous wave Doppler ultrasound - a technique in

which the transducer emits and receives the ultrasound

beam continuously, enabling the measurement of high

velocity blood flow, such as occurs through heart valve

stenoses. Measures continuously.

DOPPLER

• spectral Doppler ultrasound - a form of ultrasound

image display in which the spectrum of flow velocities is

represented graphically on the Y-axis and time on the X-

axis; both pulse wave and continuous wave doppler are

displayed in this way

• pulse wave Doppler ultrasound - a technique in which

the transducer emits ultrasound in pulses. Measures

velocity at a certain point in time.

• continuous wave Doppler ultrasound - a technique

in which the transducer emits and receives the ultrasound

beam continuously, enabling the measurement of high

velocity blood flow, such as occurs through heart valve

stenoses. Measures continuously.

QUESTIONS????CLEAR AS MUD???

ULTRASOUND EXAM

• Patient Prep

-Fasting 10-12 hours, do not withhold water.

-dorsal or lateral recumbency. I start dorsal and then shift

to lateral as I need to for certain views.

-V trough is helpful, patient comfort

-quiet dark room without interruptions

-sedation as needed; don’t be afraid to sedate; motion,

panting, tense abdominal wall all can decrease image quality.

ULTRASOUND EXAM

• Patient Prep

-Clip hair, decrease air trapping (air

decreases exam quality)

-coupling gel, improves contact and

sound transmission; should use for

high quality exam

-no enemas or barium (decreases

quality of exam)

ULTRASOUND EXAM

• Always have a standard starting point.

-some start at bladder some at liver.

• Always follow same routine so you don’t forget any organs.

-resist the temptation to go right to the lesion

• Usually work in a clockwise fashion around abdomen

• Keep a list of organs and image views by machine

HEPATOBILIARY • Liver

-place probe subxiphoid

-liver size is subjective; no standard

measures for liver.

-radiographs superior to ultrasound

for mild changes in liver size but

extreme hepatomegaly or

microhepatica can subjectively be

assessed.

-falciform fat ventral to liver. Usually

iso or hyperechoic to liver but can

mimic liver parenchyma.

LIVER SCAN

PROBE PLACEMENT

LIVER VIEWS

• Right liver

• Right caudal liver with right kidney

• Mid liver – midline (CBD, PV, CVC, AO maybe visible) plus cineloop

• Left liver

• Transverse mid liver (with gall bladder)

• Transverse right and left liver (optional)

• Liver spleen comparison (either in same image if possible or on split

screen)

HEPATOBILIARY

• Liver parenchyma

-normal echogenicity - equal to (isoechoic) or slightly more

echogenic (hyperechoic) than the renal cortex of right kidney and

less than (hypoechoic) to the spleen. Always compare with these

views.

-Cats compare echogenicity of liver to falciform fat and not spleen.

-homogenous, coarser than spleen

• Liver capsule

-smooth, hyperechoic, caudoventral borders are sharp.

NORMAL LIVER

HEPATOBILIARY

• Liver

-anechoic/hypoechoic tubular structures are portal and

hepatic veins and caudal vena cava

-intrahepatic portal vein branches have hyperechoic walls

(fatty and fibrous tissue) that distinguish them from hepatic

veins

-Note: hepatic veins can appear to have a hyperechoic wall if

sound beam is perpendicular to the wall. Portal veins will be

hyperechoic throughout.

NORMAL LIVER

HEPATOBILIARY

• Gallbladder

-lies to right of midline

-generally only portion of normal biliary tract seen

on ultrasound in dogs. Cats can see CBD with higher

frequencies. GB to cystic duct to CBD to duodenal

papilla to duodenum

-variably shaped, larger with fasting, usually ovoid tear

dropped shaped. Cats can be bilobed.

-wall is thin, smooth uniform

-usually anechoic due to fluid bile with distal acoustic

enhancement

-biliary sludge can be echogenic and have variable

consistency (fluid, inspissated, mucocele)

GALLBLADDER

GALL BLADDER SLUDGE

GALL BLADDER PATHOLOGYMUCOCELE

GALL BLADDER PATHOLOGY

CHOLECYSTITIS CALCULUS

FOCAL HEPATIC LESIONS

• classify by size, shape, number, margination, relative

echogenicity and texture.


• Cysts, abscesses, primary or metastatic neoplasia, hematomas,

granulomas, infarts, extramedullary hematopoiesis, nodular

hyperplasia.

• Cysts will be anechoic with distal acoustic enhancement.

• Other lesions can all appear similar on ultrasound. Needle

biopsy can help to distinguish. Correlate with history, exam,

blood work etc

• Target lesion: hyperechoic nodule with surrounding hypoechoic

rim. High correlation with metastatic lesion.

FOCAL HEPATIC LESIONSREGENERATIVE NODULES


MULTIFOCAL

NODULES CYST

FOCAL HEPATIC LESIONSHEPATOCELLULAR CARCINOMA

DIFFUSE HEPATIC DISEASE

• Diffuse parenchymal abnormalities can be a little more

difficult to detect.

• Compare echogenicity to right kidney and spleen: Is it

hyperechoic, hypoechoic, isoechoic?

• Echotexture : Is it homogenous or heterechoic?

• Subjective size assessment.


HYPERECHOIC LIVER HYPOECHOIC LIVER

Significantly darker than the

spleen.

Portal vessels would stand

out.

Leptospirosis and

cholangiohepatitis or

hepatitis

DIFFUSE LIVER DISEASE

HETERECHOIC/MIXED

ECHOGENICITY

DIFFUSE LIVER DISEASE

HEPATOCUTANEOUS

SYNDROME TARGET LESION


DIFFUSE

HYPERECHOIC• Steroid hepatopathy

• Lipidosis

• Other vacuolar hepatopathies

• Chronic hepatitis

• Fibrosis

• Cirrhosis

• Lymphoma

• Mast Cell Tumor

DIFFUSE HYPOECHOIC• Passive Congestion

• Acute hepatitis or cholangiohepatitis

• Lymphoma

• Leukemia

• Histiocytic neoplasms

• Amyloidosis


MIXED ECHOGENICITY

• Steroid hepatopathy +/- benign

nodular regeneration or other

processes

• Hepatitis

• Lymphoma

• Hepatocellular carcinoma

• Metastasis

• Necrosis

• Amyloidosis

SPLEEN

• Left cranial abdomen, usually tongue shaped and triangular on

transverse views

• Position can be variable but head is usually dorsal and have to scan

under ribs in this area to visualize

• Echogenicity – homogenous normally with a finer texture than the

liver

• Thin hyperechoic capsule, should be smooth

• Hyperechoic to liver and renal cortex

• Splenic veins can be seen exiting at the hilus (clue to distinguishing

from liver)

SPLEEN

• Images to acquire

Longitudinal Splenic head

Transverse Splenic head

Longitudinal Mid-Body Spleen

Transverse Mid-Body Spleen

SPLEEN

• Cat spleens are small

homogenous and smooth

but don’t compare to

liver.

• Splenomegaly with normal

echogenicity is often

caused by sedation.

SPLENOMEGALY

• Subjective assessment

• Dogs may be more rounded and organs may extend further caudal

and to the right.

• Cats look fat like a sausage; may fold on itself

• Can be due to sedation (normal echogenicity) but also can be seen

with extramedullary hematopoiesis, infectious disease, splenic torsion

or malignant infiltration (lymphoma or mast cell disease.

• Mast cell disease can be a common cause of splenic enlargement in

the cat.

SPLEEN

• May have diffuse or focal disease

• Note shape of spleen and appearance of capsule

• Describe lesions similar to focal liver lesions

-size, shape, number, relative echogenicity, margination,

texture if lesion breaks capsule continuity.

SPLEEN LESIONS

DIFFUSE DISEASE

• Hypoechoic

-Lymphoma

-Mast cell disease

-multiple myeloma

-splenic torsion (diffuse lacy

appearance)

-congestion

DIFFUSE DISEASE

• Heterechoic (mixed echogenic)

-Hemangiosarcoma

-Hemangioma

-Hematoma

-Nodular hyperplasia

-Extramedullary hematopoiesis

SPLEEN LESIONS

FOCAL LESIONS• Hypoechoic

-Metastatic neoplasia

-Primary neoplasia

-Nodular hyperplasia

-Extramedullary hematopoiesis

-Abscess

-Infarction

-Cyst

FOCAL LESIONS• Heterechoic (mixed echogenic)

-Hemangiosarcoma

-Hemangioma

-Hematoma

• Complex lesions

-anechoic, hypoechoic and

hyperechoic

-often what hemangiosarcomas

look like

SPLEEN LESIONS

Hyperechoic Focal Lesions

• Nodular hyperplasia

• Extramedullary hematopoiesis

• Dystrophic mineralization

• Fibrosis of chronic inflammation

• Myelolipomas – perivascular fat/fibrous capsular invaginations. Can get

very large.

Important to note benign and malignant disease can account for

similar lesions on ultrasound.

SPLEEN FOCAL LESIONS

HYPERPLASIA BENIGN LESION

FOCAL SPLENIC LESION AND MASSHIGH GRADE SARCOMA

FOCAL SPLENIC LESIONS MASS HEMATOMA

FOCAL SPLENIC LESIONMYELOLIPOMA

COMPLEX SPLENIC MASS

FELINE SPLEEN

KIDNEY IMAGING

• Image both longitudinally

and transversely

• Transverse image to see

renal pelvis and look for

renal pelvic dilation.

• Feline: 2 –5 mm (length)

• Canine: 3 – 8 mm (Length)

weight dependent

KIDNEY IMAGES

Longitudinal Midline

Longitudinal cineloop

Transverse mid kidney for renal pelvis

KIDNEY IMAGING

• Left kidney

•Lies caudal to the last rib directly behind the spleen

•Retroperitoneal location

•Usually easy to find

• Right kidney

•Lies partially under the rib cage

•Can be obscured by bowel gas

•Located dorsally below the epaxial muscles

•Tip: will be caudal to the right caudate liver lobe

KIDNEY IMAGING

• Indications:

•Abnormal size

•Altered shape and contour

•Azotemia (except pre-renal from dehydration)

•Hematuria

•Abnormal urinalysis

•Unable to palpate or visualize kidneys in a patient with suspected renal

disease.

KIDNEY IMAGING

• Renal cortex more echogenic

than the medulla

• Renal cortex (left) hypoechoic

to the spleen

• Renal cortex (right) hypo or

isoechoic to the liver

• Renal cortex

-coarsely stippled

-arcuate arteries are bright

echoic spots in cortex

• Renal Pelvis

- not seen usually

-peripelvic fat is hyperechoic

and can shadow

NORMAL KIDNEY

NORMAL KIDNEY

NORMAL FELINE KIDNEY

KIDNEY IMAGING

• Diffuse renal parenchymal disease may result in changes in

renal size, shape, and/or echogenicity, or may show no

changes at all.

• Most commonly seen ultrasound change of diffuse renal

disease is increased cortical echogenicity, with enhanced

cortico-medullary definition

• Loss of corticomedullary definition can also be seen

especially in severe cases.

DIFFUSE RENAL DISEASE

RENAL LYMPHOMA

KIDNEY IMAGING

• Chronic renal disease may result in a decrease in size, irregular

capsule, increased cortical thickness, loss of corticomedullary

definition

• Differentials for diffuse chronic renal disease -

nephrocalcinosis, glomerulonephritis, chronic pyelonephritis,

congenital renal dysplasia, end stage kidney disease, and

chronic interstitial nephritis.

• Enlarged, hyperechoic kidneys may indicate FIP, amyloidosis,

acute tubular necrosis (as seen with ethylene glycol toxicity),

and lymphosarcoma

CHRONIC KIDNEY DISEASE

CORTICAL

THICKENING RENAL INFARCT

KIDNEY IMAGING

• Medullary rim sign - a hyperechoic line at the cortico-

medullary junction is visible. This is now considered a non-

specific finding, and can be seen in patients without renal

disease.

KIDNEY IMAGING

• Focal renal disease may be due to cysts, abscesses, hematomas,

primary and metastatic neoplasia, and infarcts.

• Reduced cortical echogenicity or multifocal hypoechoic nodules or

masses have been described with lymphoma as well diffuse

hyperechogenicity.

• Other renal neoplasia such as carcinoma usually result in focal mass

lesions of mixed echogenicity.

• Entire renal structure can be infiltrated by neoplasia making it difficult

to recognize as a kidney

• Can’t differentiate tumor type on ultrasound exam alone, consider

other differentials such as abscess, hematoma, and necrosis as well.

KIDNEY PATHOLOGYRENAL MASS FOCAL

KIDNEY PATHOLOGYPOLYCYSTIC KIDNEY

KIDNEY IMAGING

• Hydronephrosis

•Gradual dilation of ureters, pelvis and medulla due to

obstruction.

•Progressive dilation and replacement of kidney with an

anechoic fluid-filled structure

•Cortex becomes compressed and thin

• Perinephric pseudocysts

•Normal appearing kidney with anechoic cyst surrounding the

cortex

KIDNEY IMAGING

HYDRONEPHROSIS/HY

DROURETER CANINE

HYDRONEPHROSIS

FELINE

KIDNEY IMAGING

Ureter Calculus

KIDNEY IMAGING

Perinephric pseudocyst

KIDNEY IMAGING

• Pyelonephritis

•Dilation to renal pelvis and ureter (more echogenic fluid)

•Hyperechoic renal cortex and medulla

• Renolithiasis

•Almost always in the renal pelvis

•Look for acoustic shadowing of stone

KIDNEY IMAGINGRENOLITH

KIDNEY IMAGING

• Neoplasia can usually be diagnosed with a fine needle

biopsy

• Diffuse disease needs a wedge biopsy

URINARY BLADDER

• Anechoic fluid-filled structure in the caudal

abdomen

• Size is dependent on volume of urine in the

lumen

• Sometimes falls back into the pelvis

• Should be imaged transversely and longitudinally

• Acoustic window for the caudal aorta, caudal vena cava,

sublumbar lymph nodes, and uterus.

URINARY BLADDER IMAGING

• Images to acquire

Longitudinal Midline Body

Longitudinal Midline Trigone

and Proximal Urethra

(still image and cineloop)

Transverse Mid-body

Urinary Bladder

URINARY BLADDER

• Sonographic appearance

-Outer hyperechoic serosa

-Hypoechoic smooth muscle and mucosa

-Wall image should be uniform

-Normal thickness 1-2 mm when distended; appears more thickened when

empty

-Colon may impinge and distort the wall

• Ureters should not be seen entering trigone; may see ureter papilla or ureter jet

• Anatomy – Apex, body, trigone, proximal urethra

NORMAL BLADDER

LONGITUDINAL BODY

LONGITUDINAL BODY

WITH URETHRA

NORMAL BLADDER

Transverse

Mid Body

URINARY BLADDER LESIONS

• Calculi (stones)

•Highly echogenic with have acoustic shadowing

•Gravity-dependent (turn the patient)

• Neoplasia

•Project from the wall into the lumen

•Can also cause diffuse irregular thickening

•Usually mixed echogenicity

FNA of TCC is not recommended due to tumor seeding

• Blood clots

•Irregular, hypo/hyperechoic masses

•May be mobile or adhered to bladder wall

• Can use color doppler to help distinguish clot from neoplasia


MULTIPLE CALCULI

PROBALE AMM. URATE MULTIPLE CALCULI


FOCAL TRANSITIONAL

CELL CARCINOMA

TRANSITIONAL CELL

CARCINOMA

URINARY BLADDER TCC


• Cystitis may cause thickening or irregularity of the mucosa, mainly

involving the cranioventral bladder wall. Blood clots may be associated

with cystitis, as are calculi and echogenic urine sediment.

• Can see polypoid cystitis

-more of a stalk versus wide attachment

-can mimic neoplasia

• Bladder rupture is not reliably diagnosed on ultrasound exam alone.

although the presence of free abdominal fluid is easily seen. If saline or

sterile water is injected into the bladder while scanning, flow may be seen

through a defect in the bladder wall. Positive contrast cystography is more

reliable for the diagnosis of bladder rupture, however.


CYSTITIS CYSTITIS


BLADDER RUPTURE

URINARY BLADDER RUPTURE

FEMALE REPRODUCTION

• Uterus

-Tubular structure with layering

-Dorsal to urinary bladder – good place to start

-Follows up to kidneys

-Typically not seen well except if diseased or during estrus cycle

• Ovaries

-Located caudal and medial to caudal pole of kidney

-small oval; varying appearance dependent on cycle; may look cystic

FEMALE REPRODUCTION

• Pyometra

-large tubular fluid filled structure

-fluid is usually echogenic and “swirly”

• Hydrometra

-anechoic fluid smaller diameter of uterus

• Neoplasia

FEMALE REPRODUCTION

HYDROMETRA PYOMETRA

MALE REPRODUCTION

Prostate

• Found caudal to urinary bladder along

midline/ urethra

• Use urinary bladder as landmark

• Scan in transverse and longitudinal fashion

• Neutered male prostate will be small well marginated and

hypoechoic

MALE REPRODUCTIONPROSTATE

MALE REPRODUCTION

Normal

Prostate

MALE REPRODUCTION

• Benign Prostatic Hypertrophy

•Increase echogenicity

•Small anechoic cavitations are normal

•Almost always symmetrical, well defined.

• Prostatitis

•Hyperechoic – like BPH

•Multiple anechoic cavitary lesions

•Usually painful

MALE REPRODUCTION

PROSTATE - BPH

MALE REPRODUCTION

BENIGN PROSTATIC

HYPERPLASIA PARAPROSTATIC CYST

MALE REPRODUCTION

• Prostatic Abscess

-often a sequelum to prostatitis or BPH

-irregular echogenic fluid filled area

-fluid is echogenic due to blood, WBC’s and bacteria accumulation

• Paraprostatic Cyst

-”one to many bladders”

-finding two or more anechoic structures in the caudal abdomen. Can

become infected.

MALE REPRODUCTION

• Prostatic Neoplasia (Adenocarcinoma)

-often coexists with and is thought to be a sequelum to

infection.

-may see periprostatic effusion

-increased size, irregular margin, multiple hyperechoic foci

-may see dystrophic calcification (shadows)

-image sublumbar lymph nodes (common area to

metastasize)

MALE REPRODUCTION

• Testes Normal Anatomy

-coarse to medium stippled eco pattern

-rete testes: 0.2 mm wide linear structure on long axis

-epididymus: hypoechoic and stippled relative to testes

-testicular tunic: bright echogenic covering

MALE REPRODUCTIONNORMAL TESTES

MALE REPRODUCTION

• Testicular neoplasia

-Sertoli cell tumor: hyperechoic/mixed echogenic mass,

extensive organ distortion

-Interstitial Cell Tumor: focal hypoechoic, well marginated

mass

-Seminoma: coarse hypoechoic mass (variable), disrupt testes

architecture, may have fluid

• Other testicular disorders: orchitis/epididymitis, retained

testicles, granulomatous infiltrates

GASTROINTESTINAL IMAGING

• Patient prep important

• Gas will cause artifact and limit imaging

• Cannot “run” the whole bowel

• Normal sonographic appearance

● 5 sonographic layers

Serosa (hyperechoic)

Muscularis (hypoechoic)

Submucosa (hyperechoic)

Mucosa (hypoechoic)

Lumen - often filled with gas (hyperechoic)

• Duodenum, jejunum, ileum, and colon can be

individually distinguished


• Normal wall thickness:

Canine Feline

Stomach 3-5 mm Stomach 2 mm

Small Intestine 2-4 mm Small Intest 2 mm

Colon 2.5-3 mm Ileum 3 mm

Duodenum 3-5 mm Colon 1.5 mm

(usu about .1mm thicker than SI)

• Stomach 3-5 contractions/min

• Small Intestine 1-3 contractions/min

GI IMAGING STOMACH

NORMAL STOMACH ADENOCARINOMA


NORMAL INTESTINES DUODENUM


NORMAL ILEUM NORMAL ILEUM


Most common pathology I see

• Mass lesions: neoplasia – lymphoma, mast cell tumor,

adenocarcinoma; less common granulomatous lesions

• Thickened bowel wall associated with IBD or lymphoma

(mostly see in cats)

• Intussusception

• Jejunal lymphadenopathy

• Foreign bodies


THICKENED SM

INTESTINE IBD OR LYMPHOMA


• Stomach

-5 layers as intestines; limited by luminal gas

-rugal folds can be visible

-measure wall between rugal folds

-wall thickness 3-5 mm

-large fluid distended stomach concerns for obstruction or possible

motility disorder

-stomach and duodenum should have 4-5 peristaltic contractions per

minute; jejunum contracts 1-3 times minute

GI IMAGING STOMACH

NORMAL STOMACH ADENOCARCINOMA


Mass lesions

• expansive area with loss of intestinal wall layering

• May be symmetrical (more common with lymphoma) or

asymmmetrical (more common with adenocarcinoma)

• Lymphoma can have an infiltrative pattern that causes wall

thickening but retains clear wall layering


ILEUM MASS

LYMPHOMA


Intussusception

• Telescoping of bowel within itself

• Can occur anywhere along intestinal tract

• Characteristic ultrasound appearance

• Cross section shows a multilayered, concentric, target like lesion due to

multiple layers of bowel “stacked” on top of each other

• Often has hyperechoic mesentery within the center due to mesentery

telescoping with the intestine.

• Inflammation and edema may distort the image however


INTUSSUSCEPTION

LONGITUDINAL


INTUSSUSCEPTION

TRANSVERSE


Foreign Bodies

• Linear foreign bodies

-plication of bowel; sometimes can see the hyperechoic linear line

within the lumen

• Other foreign bodies will have a variable appearance and depends on

the type and acoustic impedance of the material

-hyperechoic with strong shadow or “dirty” shadow

• Dilated fluid filled intestines proximal to the suspected foreign body


FOREIGN BODY


Jejunal lymphadenopathy

• Ovoid to elongated homogenous; can see them with newer machines

• Reactive nodes get a mild heterechoic look but still remain ovoid

shaped

• Neoplastic infiltration node will get larger and often as wide as they

are long and are often hypoechoic or have a mixed echogenic

appearance.

• Maybe able to find lymphoma here if the intestines are thickened but

there isn’t a mass to aspirate


REACTIVE JEJUNAL LN

JEJUNAL LNS

LYMPHOMA


REACTIVE - LN FLUID IN CECALAREA

THE END

“Man cannot discover new oceans unless he has the courage to

lose sight of the shore.”- Andre Gide

vision is the art of seeing what is basic invisible to

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