urogenital

3 types of imaging to eval kidneys

• survey rads

• EU

• compression studies

Which view best separates the kidneys

right lateral

which view is best for eval of SIZE and shape of kidneys

VD

where are right and left kidney located

R kidney - 13th rib where cr. pole touches caudate lobe of liver

L kidney - more cd. than right kidney. Just behind gastric fundus, cd/med to splenic head

how are cat kidneys located differently from dog

more cd (same thing with right kidney more cr.)

dog kidney size vs cat kidney size

dog - 2.5-3.5 x length L2

cat - 1.9-3.2 x length L2

shape of kidneys dog vs cat

dog - bean

cat - oval

what might you see in the renal pelvis region of cat that is different from dog kidneys

peripelvic fat

5 reasons why we see less than 2 kidneys (don’t think dz)

• pyelonephrectomy

• lack of RP fat

• summate with RP fluid

• superimpose with GI and other viscera

• poor exposure technique

3 reasons why we see more than 2 kidneys

• congenital anomaly

• artifact/interp error

• renal transplant

4 reasons we see abnormal position of kidneys

• incidental

• lots of RP fat, distended stomach, postural changes

• ectopic kidneys

• masses (liver, spleen, adrenal, ovaries)

6 reasons for generalized increase in kidney size

• comp hypertrophy

• hydronephrosis - can be severe

• acute inflam

• toxic renal

• neoplasia

• PSS

3 reasons for focal multifocal increase of kidney size

• neoplasia

• large renal cysts/PCRD

• FIP

5 reasons for decreased kidney size

• chronic inflam

• end stage renal disease

• infarcts

• familial dysplasia, congenital disease 

• renal hypoplasia 

5 focal irregular shape changes kidneys

• infarcts

• neoplasia

• end stage renal or chronic inflam

• renal cysts/PCRD

• FIP

5 reasons for weird margination around kidneys

• acute inflam

• toxicity

• acute obstruct

• trauma

• aggressive neoplasia

3 causes of focal increased opacity of kidneys

• renal calculi

• dystrophic calcification

• mineralized cyst, calcified tumors

2 reasons for diffuse increased opacity of kidneys

• IV contrast administration

• diffuse calcification (nephrocalcinosis)

2 reasons for decreased renal opacity

• vesiculoreteral ureflux

• infection with gas bacteria

4 indications of EU

• incontinence

• indistinct RP space

• renal/ureteral calculi

• cannot find kidneys on rads

4 contraindications for EU

• clinical dehydration

• sensitive to contrast media

• multiple myeloma

• combined renal and hepatic failure

6 reasons for Diffuse increase in cortical echogenicity kidneys

• Normal in cats – fat deposition in the tubules

• inflam disease -  glomerulonephritis, interstitial nephritis

• End-stage renal disease – kidneys also small and irregular

• Toxic - ethylene glycol tox

• Renal dysplasia – kidneys also small and irregular

• Neoplasia

what are the 3 ways to describe CM junction distinction

• retained - both equally bright

• enhanced - medulla normal, cortex bright

• decreased -medulla also bright

is the medullary rim sign something to be worried about

no! can see in both normal small dogs and diseased kidneys

2 reasons for decreased CM junction distinction

• chronic renal disease

• renal dysplasia

3 things that are abnormal and anechoic in kidneys

• cysts

• abscess

• neoplasia

4 things abnormal and hypo/hyperechoic in kidney

• neoplasia

• infarct

• abscess, granuloma

• hematoma

2 reasons you might see mineralization in kidneys

• dystrophic

• calculi 

what are 2 reasons for mild and severe distension of renal pelvis

mild - full bladder, diuresis/PU

severe - pyelonephritis, obstruction

YOUNG animal with renal disease that results in 2 small kidneys

hypoplastic/dysplastic kidneys

condition where one kidney becomes enlarged to compensate for a down kidney

compensatory hypertrophy

• kidney preserved architecture

• decreased CM distinction

when in the disease process can you see pyelonephritis on rads

chronic or healed

2 causes of pyelonephritis

hematogenous or ascending infxn

acute vs chronic pyelonephritis rad and ultrasound findings

acute

• slight enlargement of kidneys ± RP effusion

• smooth contours and diffusely hyperechoic

• ↓CM distinction

• pus/echogenic content in pelvis

• pyelectasia

Chronic

• small to normal sized kidneys with irregular shape

• pelvis distorted

• ↓CM distinction

small, irregularly lumpy, bumpy shaped kidneys, ↓CM distinction ± mineralization 

end stage kidneys

hydronephrosis is caused by

partial or complete obstruction of urine outflow in renal collecting system or ureters

4 causes of congenital vs acquired hydronephrosis

Congenital

• kinking or partial obstruction of ureters 2° to kidney or ureteral malposition

• Stenosis

• compression from ureterocele

• associated with ectopic ureters or other congenital malformations without true obstruction

Acquired

• Obstruction from urinary calculi, neoplastic or inflam masses

• accidental ligation

• ureteral stricture

• parasites (dioctophyma renale)

enlarged smooth kidneys with distended pelvis ± distended ureters

hydronephrosis

polycystic renal disease (PCRD) is heritable in what species and breed

persian cats - autosomal dominant

what organ likes to accumulate cysts with PCRD

kidneys and liver

what is the sequela of severe PCRD

chronic renal failure - parenchyma distorted and non-fxn 

bilateral renomegaly with irregular margins with many cysts in the cortex that are anechoic with distal acoustic enhancement

PCRD

What is dog and cat #1 kidney neoplasia

dog = carcinoma

cat = LSA

cat renal carcinoma

• focal enlargement

cat renal lymphoma

• generalized enlargement

which is more characteristic of lymphoma vs mets

lymphoma = left

mets = right

what is going on with this kidney

mass - neoplasia

• focal/multifocal nodules with renal enlargement

what is going on with this kidney

mass - cystic carcinoma

• hypo/iso/hyperechoic ill defined mass ± cysts and mineralization 

what types of stones are typically nephroliths

• calcium oxalate

• struvite

nephrolith and ureterolith 

what is creating this shadow

nephrolith

on lateral radiographs you find these mineral opacities in the kidneys and ureters. You probe an ultrasound over it and find a mineral opacity that has a distal acoustic shadow

Nephrolith

what is the best mode of imaging for a ruptured kidney

EU

fluid opacity in the RP region that makes it hard to make out the kidneys. EU has leakage of contrast into RP space and a hematoma is seen on ultrasound

ruptured kidney

normal location of the ureters

arise from renal pelvis —> dorsal to mid point to trigon level of bladder as enter peritoneal cavity —> turn ventrally and empty bladder at trigon

what is a structure often confused for ureteral mineral (PITFALL)

end on deep circumflex iliac vessel

ureters are not normally visible on rads, what do you need to see ureters

EU/IVP

rad and ultrasound findings of ureteroliths

Rad findings - Can be seen

Ultrasound findings

• hyperechoic structures with distal acoustic shadowing

• Variable size

• If obstruction—> hydronephrosis and hydroureter prox. and a normal ureter distally

degree of distension of renal pelvis and ureter depend on what 2 factors

• degree of severity

• chronicity of obstruction

preferred method to ID ureteral rupture

EU/IVP

dog with trauma hx has decreased RP detail and leakage of contrast material into both the peritoneal and RP space

ruptured ureter

• avulsion — peritoneal space

• rupture — RP space

how would you be able to differentiate a ruptured kidney vs ureter

kidney rupture - injured kidney with opacify inhomogenous

ureter rupture -only one ureter will light up with contrast and deposit into bladder

congenital defect that affects females more and results in urinary incontinence since birth

ectopic ureters

2 common locations for ectopic ureters

• prox urethra - after sphincter (IUS)

• vaginal vault

**can have multiple or fenestrated openings

what combo of imaging modalities is the best way to view ectopic ureters

negative contrast cystogram (make bladder black) + EU (highlight ureters)

female dog with history of incontinence since birth 

ectopic ureters

• normal non-distended bladder

• hydroureter

• accumulation of contrast not in bladder

• abnormal termination location of ureters

• ureters and kidneys may appear normal - trace to abnormal termination site

• ± hydroureter/hydronephrosis if cause obstruction

3 ways to do contrast cystography on bladder

• Positive Contrast Cystogram -bright

• Negative Contrast Cystogram –dark/gas

• Double Contrast Cystogram –both

T/F bladder changes are seen on rads normally

FALSE - need cystogram or ultrasound for dx

what are the 3 parts of the bladder

• The vertex-blunt cr. Aspect (round)

• The body- middle

• The neck (trigone) – cd. aspect

what 4 things that could make the bladder hard to see on rads

• insufficient fat

• not distended

• superimposed intestinal loops

• pelvic muscles

what organs border the bladder dorsally in female and male

male = colon

female = uterus

how does a cat bladder look different from dog

further into abd and longer neck than dog

what are the 3 distensible organs

• bladder

• stomach

• uterus

describe opacity of normal bladder

less opaque at periphery (less fluid), thicker looking in the center

3 abnormalities that will make the bladder disappear

• empty bladder

• lack visceral contrast 

• displacement of bladder

what 2 organs can displace the bladder

colon and uterus

4 places the bladder can be displaced to abnormally

• perineal hernia

• inguinal hernia

• abdominal wal hernia

• entire bladder into pelvic canal (not always clinically significant)

3 reasons for distended bladder and small bladder

distended

• normal

• obstruction

• neurogenic

small bladder

• empty bladder

• cystitis

• ectopic ureters

what 2 things can alter shape/margin of bladder

• adjacent mass/structure

• primary bladder abnormality

**eval at complete distention with contrast

4 reasons for increased opacity of bladder

• radiopaque calculi

• IV contrast admin for something else

• dystrophic mineral of neoplasia

• dystrophic mineral of chronic inflam

2 reasons for decreased opacity in the bladder

• air opacity in bladder wall - emphysematous cystitis (diabetes mellitus)

• air opacity in lumen - gas bact diabetes, iatrogenic cath/cysto

positive contrast cystography best highlights

position and wall integrity

negative conrast cystography in combination with EU highlights what 3 conditions

• ectopic ureter

• localize bladder we not seen on rads

• non-opaque bladder calculi

double contrast cystography highlights

mural diseases and intramural filling defects

what are 9 indications to use cystography

• Suspect urinary bladder rupture**

• Localization of urinary bladder relative to suspected hernia**

• Non-observable urinary bladder and differentiation of bladder from caudal abdominal mass lesions*

• Stranguria, dysuria*

• Hematuria

• Pyuria

• Proteinuria

• Crystalluria

• Persistent or recurrent UTI

what 3 lab values will contrast effect

• USG

• sediment

• inhibition of growth of culture pathogen

what are 4 things to eval when looking at cystography

• wall thickness > 2 mm

• wall integrity

• mucosal surface

• intraluminal filling defects

5 examples of attached intraluminal defects bladder

• neoplasia

• blood clot

• polyps

• hematoma

• ureterocele

3 types of free intraluminal defects bladder

• calculi

• hematoma, blood clot

• gas bubbles

6 complications of cystography

• air embolism

• trauma

• bladder rupture

• hemorrhage from distention of diseased bladder wall

• catheter kinking/knot

• bacterial contamination

3 etiologies that might distort bladder wall

• neoplasia

• artifact due to small bladder size

• cystitis

bladder

A = cystitis

B = emphysematous cystitis

C= polypoid cystitis

key ultrasound feature of cystitis

irregular thickened hypoechoic urinary bladder wall

what part of the bladder is most affected by cystitis

cranioventral aspect

neoplasia of the bladder likes to affect what region

trigon and dorsal wall

OLD DOG bladder

TCC/neoplasia

key feature of bladder neoplasia on ultrasound

mass or polyp lesion in the trigon or dorsal wall

when dx urinary bladder rupture, what artifact often looks like a hole in the wall

refraction artifact at apex of bladder

5 etiologies that can distort bladder content

• pseudosludge

• sediment

• iatrogenic gas bubbles

• calculi

• blood clot

bladder

sandy calculi