Urinary Tract Imaging Flashcards
radiographic kidney evaluation
- size
- border/shape
- mineral opacities
- skeletal abnormalities
normal kidney size in dogs on radiographs
2.5 - 3.5x L2
normal kidney size in cats on radiographs
2-3x L2
DDX for enlarged kidneys
hydronephrosis
polycystic kidney disease
perinephric pseudocysts
neoplasia
acute nephritis
compensatory hypertrophy
portosystemic shunts
FIP
ddx for small kidneys
chronic renal disease
agenesis/aplasia
dysplasia
urethrogram
positive contrast retrograde study used to ID luminal filling defects, extraluminal compressive lesions, or leakage
single contrast cystography
injection of iodinated contrast into the bladder
best for bladder rupture
double contrast cystography
injection of iodinated contast followed by air
IV pyelography
iodinated contrast injected IV to evaluate renal perfusion
components to evaluate kidneys on ultrasound
- size
- border
- echogenicity
- corticomedullary interface
- renal pelvic dilation
- subcapsular fluid/cell infiltrate
- retroperitoneal fluid
- masses/nodules
kidney size in dogs
3-9 cm depending on body size
kidney size in cats
3.5-4.4 cm long
echogenicity of US structures in young dogs
medulla < cortex < liver < spleen
echogenicity of US structures in dogs > 3 yo
medulla < liver < cortex < spleen
what does renal mottling suggest
inflammation vs neoplasia vs infarction
what does decreased corticomedullary distinction suggest
CKD vs AKI
ckd = more echogenic (hyperechoic fibrosis)
aki = less echogenic (edema)
pyelectasia
renal pelvic dilation
- LOW pressure
best viewed in transverse
ddx: pu/pd, pyelonephritis, IV fluids
hydronephrosis
dilation of the kidney and pelvis
- high pressure event
ddx: obstruction
subcapsular fluid ddx
perinephric pseudocysts
ureteral obstruction
hematoma
subcapsular cellular infiltrate ddx
lymphoma
what does retroperitonal fluid look like on US
angular margins
unlike subcapsular fluid which creates smooth margins
DDX: AKI, coagulopathy, retroperitonitis
thick bladder wall at the apex DDX
polyps
inflammation
cystitis
thick bladder wall at the trigone ddx
neoplasia
- trigone mass
- mineralization
what is the gold standard for diagnosing ureteral obstructions + ureteroliths
non contrast enhanced CT
can use in combination with ultrasound to increase sensitivity
