ultrasonography dr. leeann pack dipl. acvr. normal anatomy - liver size of liver –assessed...
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Ultrasonography
Dr. LeeAnn Pack
Dipl. ACVR
Normal Anatomy - Liver
Size of liver– Assessed subjectively (rads are superior)
Parenchyma – Homogenous, uniform– Interrupted only by portal & hepatic veins
Portal veins have echogenic walls Hepatic veins = black tubes Hepatic arteries are not seen
Normal Anatomy - Liver
Echogenicity– Dog: Spleen > liver > kidney– Cat: Spleen = liver > kidney
Texture– More coarse texture than spleen
Normal Anatomy
Diaphragm
Portal vein
Normal
Abnormal
Vasculature Portal veins
– More echogenic than hepatic veins due to surrounding fibro-fatty tissue
– Less visible with PSS, fibrosis, & cirrhosis
Hepatic veins
– Best seen cranially near diaphragm (emptying into vena cava)
– Walls not visible
Vasculature
Indications for US - GB
Thickened wall Stones Mucoceles Cholestasis Cholecystitis “Sludge” Icterus
US Technique - GB
How to find it? Anechoic, round to
oval structure to right of mid-line
Normal Anatomy - GB
Wall is thin echogenic line
Size of GB is variable
Cat GB is bi-lobed
Feline Bi-lobed GB
Enhancement
Pathology - GB
Kiwi-shaped extensions– GB mucocele
Hyperechoic areas in wall– Edema– Acute inflammation
Large, hyperechoic sediment– Sludge vs Cholelith
Cholelith – usually cause acoustic shadowing
GB Mucocele
GB Mucocele
GB Mucocele + perf
Cholelith
Sludge in GB
Thickened GB Wall
Normal Anatomy Spleen
Normal
Splenic Hilus
Abnormal
Ultrasound Technique - Spleen
Left side of body Head of spleen
– Under border of rib cage on left
Body & tail of spleen– Along left body wall– Ventral or lateral to left kidney
Scan sagittal & transverse
Anatomy
Size of normal spleen variable– Assessed subjectively– Enlarged spleen may cross midline or
extend caudally to the bladder Parenchyma
– Homogenous, finely textured Echogenicity
– Dog: Spleen > liver > kidney– Cat: Spleen = liver > kidney
Normal Spleen
Anatomy
Capsule– Smooth, regular, VERY echogenic
Splenic veins– Only other structure normally visualized– Poorly visualized except near hilus
“Whale tail”
– Enlargement subjective Hilus
– Check for lymphadenopathy
Splenic Hilus
Non Homogenous
Splenic Mass
Neoplasia
Lymphosarcoma– Diffuse or focal/multifocal– Hypoechoic or hyperechoic– Can appear normal
Hematoma, hemangioma, hemangiosarcoma– Unable to differentiate– Focal– Hypoechoic, hyperechoic or mixed
Lymphosarcoma
Hemangiosarcoma
Thrombosis
Splenic Thrombus
Myelolipoma
U/S Technique - Bladder
Use high-resolution transducers (7-12 MHz)
Located very superficially Pressing too hard distorts the image
Normal Anatomy - Bladder
Bladder wall thickness (1-2mm)– Dog: 1.6 mm– Cat: 1.7 mm
Wall thickness changes with bladder size
Ureters & urethra not visible unless filled with urine
Pathology Intraluminal changes
– Urinary calculi – Gas bubbles – Cellular and crystalline debris– Blood clots
Bladder wall changes– Cystitis– Neoplasia– Polyps
Urinary Calculi Calculi very hyperechoic Large calculi can cause acoustic
shadowing Ballotment doesn’t usually make calculi
move, but standing the animal will
Urinary Calculi
Calculi
Cystic Calculi
Cystic Calculi
Debris
Variable echogenicity Can become thick enough to form
confluent layer with bladder wall Vigorous ballotment will cause a
swirling pattern – looks like snow globe
Cystitis Chronic cystitis leads to diffuse thickening
of wall Small mucosal masses sometimes present Muscular hypertrophy caused by chronic
partial lower urinary tract obstruction Emphysematous cystitis
Cystitis
Chronic Cystitis
Neoplasia Single or multiple masses Irregularly shaped, broad-based hypo or
hyperechoic masses protruding into bladder lumen
Transitional cell carcinoma most common
Neoplasia
Neoplasia
Indications for U/S - Kidneys
U/S very useful for evaluating:– Size, shape, position, echogenicity
In some cases, has replaced EU’s– Provides more info regarding morphology
Does NOT provide information about renal function
U/S Technique - Kidneys
The left kidney is found just medial to the head of the spleen – Usually close to the body wall so start at body wall
and pull transducer medial
The right kidney resides in the renal fossa of the liver– Start at liver and proceed caudal along body wall
– Can be more difficult to find and more difficult to make a “pretty image”
– May be under the rib cage
Normal Anatomy - Kidney Location
– Left kidney:caudal to stomach & caudo-medial to spleen
– Right kidney: within caudate process of caudate lobe of liver
Length (in sagittal plane): – Dog: depends on size & weight of the dog – Cat: 2.8-4.2 cm
Echogenicity– Cortex hyperechoic to the medullary portion
Normal Anatomy - Kidney The cortex and medulla should be of equal
thickness and clearly defined Capsule is slightly hyperechoic Best to see renal pelvis on the transverse
view
Normal Anatomy - Kidney
Note the Capsule
Lymphosarcoma
Renal Infarct
Polycystic Kidneys
Polycystic Kidneys
Lymphosarcoma
Interstitial Nephritis
Ethylene Glycol
Large Renal Cyst
Nephrolith
Normal Sagittal
Hydronephrosis
Hydronephrosis
Hydronephrosis
Hydroureter
Normal Transverse
Hydronephrosis