Kidney and Bladder Kidney and Bladder USUS

Mike AckerleyMike Ackerley

KidneyKidney

Advantage over other modalities?Advantage over other modalities? What do you see normally?What do you see normally? What can we diagnose?What can we diagnose?

AdvantagesAdvantages Ease with which the extent of the disease Ease with which the extent of the disease

can be determined within the kidney for can be determined within the kidney for focal diseasefocal disease

Ease of assessment of renal pelvic or Ease of assessment of renal pelvic or ureteral dilation when fluid distendedureteral dilation when fluid distended

The location and relevance of renal The location and relevance of renal mineralization can also be assessedmineralization can also be assessed– When radiographically ID focal renal pelvic or When radiographically ID focal renal pelvic or

ureteral mineral opacities and the question of ureteral mineral opacities and the question of whether hydronephrosis is presentwhether hydronephrosis is present

Biopsy or fine-needle aspiration can be Biopsy or fine-needle aspiration can be expedited by ultrasonographic guidance, expedited by ultrasonographic guidance, improving the margin of safety as well. improving the margin of safety as well.

NormalsNormals Length in saggital planeLength in saggital plane

– Dog: variable with size of dogDog: variable with size of dog– Cat: 2.8 – 4.2 cmCat: 2.8 – 4.2 cm

CortexCortex– In dogs more bright than the liver, but less bright than In dogs more bright than the liver, but less bright than

spleenspleen– In cats variable, may be equal brightness to that of liver In cats variable, may be equal brightness to that of liver

and approach that of the spleenand approach that of the spleen Medullary PapillaeMedullary Papillae

– The renal medulla in dogs and cats is less echogenic The renal medulla in dogs and cats is less echogenic than the cortex. than the cortex.

Arcuate vessels Arcuate vessels Pelvic recess Pelvic recess Renal vessels Renal vessels Renal pelvis Renal pelvis

– If high resolution (7.5 – 10 MHz) transducer is usedIf high resolution (7.5 – 10 MHz) transducer is used

Capsule

Pelvis

Cortex

Medulla

PathologyPathology DistensionDistension

– Diuresis: bilaterally symmetrical and usually mildDiuresis: bilaterally symmetrical and usually mild– Hydronephrosis: pelvic dilation may become very gross, Hydronephrosis: pelvic dilation may become very gross,

with only a think rim of surrounding parenchymal tissue with only a think rim of surrounding parenchymal tissue (idiopathic, or secondary to ureteric obstruction)(idiopathic, or secondary to ureteric obstruction)

– Renal calculus: strongly reflective surface with distal Renal calculus: strongly reflective surface with distal acoustic shadowing also present.acoustic shadowing also present.

– Chronic pyelonephritis: the pelvis may dilate while the Chronic pyelonephritis: the pelvis may dilate while the diverticula remain smalldiverticula remain small

– Renal neoplasia: secondary dilation of the renal pelvis Renal neoplasia: secondary dilation of the renal pelvis and proximal ureter, or mechanical obstruction of the and proximal ureter, or mechanical obstruction of the pelvispelvis

– Ectopic ureter: due to stenosis of the ureter ending Ectopic ureter: due to stenosis of the ureter ending and/or ascending infectionand/or ascending infection

– Renal pelvic blood clot: following renal biopsy, Renal pelvic blood clot: following renal biopsy, coagulopathy, bleeding neoplasm, idiopathic renal coagulopathy, bleeding neoplasm, idiopathic renal hemorrhage, or traumahemorrhage, or trauma

HydronephrosisHydronephrosis

HydronephrosisHydronephrosis

PathologyPathology

Focal parenchymal abnormalitiesFocal parenchymal abnormalities– Well circumscribed, anechoic Well circumscribed, anechoic

parenchymal lesionparenchymal lesion– Hypoechoic parenchymal lesionHypoechoic parenchymal lesion– Hyperechoic parechymal lesionHyperechoic parechymal lesion– Heterogeneous/complex parenchymal Heterogeneous/complex parenchymal

lesionlesion– Medullary rim signMedullary rim sign– Acoustic shadowingAcoustic shadowing

PathologyPathology

Well circumscribed, anechoic Well circumscribed, anechoic parenchymal lesionparenchymal lesion– Thin smooth wall: single or multiple Thin smooth wall: single or multiple

cystscysts– Thick/irregular wall: Thick/irregular wall:

CystCyst HematomaHematoma AbscessAbscess neoplasianeoplasia

PathologyPathology

Hypoechoic parenchymal lesionHypoechoic parenchymal lesion– NeoplasiaNeoplasia

LymphosarcomaLymphosarcoma

Hyperechoic parenchymal lesionHyperechoic parenchymal lesion– NeoplasiaNeoplasia

11º: chondrosarcoma, hemangiomaº: chondrosarcoma, hemangioma Metastatic: hemangiosarcoma, thyroid Metastatic: hemangiosarcoma, thyroid

adenocarcinomaadenocarcinoma

PathologyPathology

Heterogeneous/ Complex Heterogeneous/ Complex parenchymal lesionparenchymal lesion– NeoplasiaNeoplasia– AbscessAbscess– HematomaHematoma– GranulomaGranuloma– Acute infarctAcute infarct– Polycystic diseasePolycystic disease

Polycystic KidneysPolycystic Kidneys

Renal InfarctRenal Infarct

PathologyPathology

Medullary rim signMedullary rim sign– Normal in catsNormal in cats– NephrocalcinosisNephrocalcinosis– Ethylene glycol toxicityEthylene glycol toxicity– Chronic interstitial nephritisChronic interstitial nephritis– Cats - FIPCats - FIP

PathologyPathology

Acoustic ShadowingAcoustic Shadowing– Deep to pelvic fatDeep to pelvic fat– Renal calculusRenal calculus

NephrolithNephrolith

PathologyPathology

Diffuse parenchymal abnormalitiesDiffuse parenchymal abnormalities– Increased cortical echogenicityIncreased cortical echogenicity– Decreased corticomedullary definitionDecreased corticomedullary definition

PathologyPathology Increased cortical echogenicityIncreased cortical echogenicity

– Normal catsNormal cats– Inflammatory diseaseInflammatory disease

GlomerulonephritisGlomerulonephritis Interstitial nephritisInterstitial nephritis FIPFIP

– Acute tubular necrosis/nephrosis (toxins)Acute tubular necrosis/nephrosis (toxins)– Renal dysplasiaRenal dysplasia– NephrocalcinosisNephrocalcinosis– NeoplasiaNeoplasia

Diffuse lymphosarcomaDiffuse lymphosarcoma

PathologyPathology

Decreased corticomedullary Decreased corticomedullary definitiondefinition– End-stage kidneysEnd-stage kidneys– Multiple small cystsMultiple small cysts

What can we diagnose?What can we diagnose?

InfarctsInfarcts Cysts/Abscess/HematomaCysts/Abscess/Hematoma Renal calculusRenal calculus Big neoplasiaBig neoplasia Pelvic DilationPelvic Dilation

BladderBladder

Advantage over other modalities?Advantage over other modalities? What do you see normally?What do you see normally? What can we diagnose?What can we diagnose?

AdvantagesAdvantages

Able to evaluate bladder wall Able to evaluate bladder wall thicknessthickness

Able to visualize non-radiopaque Able to visualize non-radiopaque stones/cyrstals (C U)stones/cyrstals (C U)

CystocentesisCystocentesis

NormalsNormals

Best when bladder moderately full Ovoid in Best when bladder moderately full Ovoid in shape, with slight elongation caudally at shape, with slight elongation caudally at trigonetrigone

Don’t normally see uretersDon’t normally see ureters Three layers (Three layers (∆∆ with size) with size)

– Mucosa: HyperechoicMucosa: Hyperechoic– Muscular: Hypo-Muscular: Hypo-– Serosal: Hyper-Serosal: Hyper-

Normal wall thickness (cat): 1.7 mm Normal wall thickness (cat): 1.7 mm ± 0.56± 0.56 Normal wall thickness (dog): 1.6 mmNormal wall thickness (dog): 1.6 mm

PathologyPathology

CalculiCalculi– acoustic shadows are observed deep to acoustic shadows are observed deep to

calculi that exceed the diameter of the calculi that exceed the diameter of the beam.beam.

– echogenicity and acoustic shadow echogenicity and acoustic shadow generation are independent of chemical generation are independent of chemical composition (doesn’t matter struvite VS composition (doesn’t matter struvite VS cystine)cystine)

– Ballottement doesn’t move calculi, but let Ballottement doesn’t move calculi, but let animal stand and calculi will fall. animal stand and calculi will fall. Helps differentiate from mineralized bladder wall Helps differentiate from mineralized bladder wall

and colonic shadowingand colonic shadowing

Cystic CalculiCystic Calculi

PathologyPathology

Gas bubblesGas bubbles– Will float to the top, to differentiate from Will float to the top, to differentiate from

calculicalculi Blood clotsBlood clots

– non-shadowingnon-shadowing Crystalline sedimentCrystalline sediment

– Vigorous ballottementVigorous ballottement– Swirling pattern when standingSwirling pattern when standing

Blood ClotBlood Clot

PathologyPathology

Mural changesMural changes– CystitisCystitis– NeoplasiaNeoplasia

PathologyPathology

CystitisCystitis– Chronic cystitis results in diffuse Chronic cystitis results in diffuse

thickening of the bladder wall thickening of the bladder wall – bladder wall becomes abnormally bladder wall becomes abnormally

hypoechoic, and the normal layering hypoechoic, and the normal layering becomes less parallel becomes less parallel

– normal sonographic appearance of the normal sonographic appearance of the bladder does not rule out the presence of bladder does not rule out the presence of mild or acute cystitis or idiopathic lower mild or acute cystitis or idiopathic lower urinary tract disease in cats urinary tract disease in cats

Chronic CystitisChronic Cystitis

PathologyPathology

NeoplasiaNeoplasia– TCC: irregularly shaped, broad-based, TCC: irregularly shaped, broad-based,

hypoechoic masses protruding into the hypoechoic masses protruding into the bladder lumen bladder lumen

– echo pattern depends on if if fibrosis, echo pattern depends on if if fibrosis, mineralization, and necrosis have mineralization, and necrosis have developed developed

– An abrupt transition often observed An abrupt transition often observed between neoplastic mass & adjacent between neoplastic mass & adjacent bladder wall bladder wall

NeoplasiaNeoplasia

PathologyPathology Sonographic appearance of polypoid cystitis, Sonographic appearance of polypoid cystitis,

adherent blood clots, and mural hematomas is adherent blood clots, and mural hematomas is similar to that of neoplasia similar to that of neoplasia

Observation of ureter dilation adjacent to the Observation of ureter dilation adjacent to the bladder wall mass & focal medial iliac bladder wall mass & focal medial iliac lymphadenopathy tends to support the lymphadenopathy tends to support the diagnosis of neoplasiadiagnosis of neoplasia

Need aspirate, but must weigh that benefit Need aspirate, but must weigh that benefit against the possibility of seeding the needle against the possibility of seeding the needle tract with tumor cells tract with tumor cells

Traumatic catheterization is useful to retrieve Traumatic catheterization is useful to retrieve cells from the masscells from the mass

What can we diagnose?What can we diagnose?

Crystalline sedimentCrystalline sediment CalculiCalculi Blood clots?Blood clots? GasGas