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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 Portal vein Diaphragm 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 Splenic Hilus Normal 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 & caudomedial 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