Radiographs: Lower Urinary Tract Flashcards
where is the bladder located on lateral and V/D projections
ventral to the colon
midline (covered by vertebral column) on V/D
compression radiographs
using a spoon/flat object to push down on caudal abdomen to move bowel loops away from bladder and flatten the abdominal wall to aid in visualizing radio-dense urinary stones
what stones are visible on radiographs
struvite or Ca oxalate
positive contrast cystogram
injecting the bladder with iodinated contrast to evaluate bladder margins and leakage
double contrast cystogram
injecting the bladder with air (negative contrast) and iodinated contrast to evaluate mucosal surface and radiolucent stones
air: outer margins of bladder
contrast: center of bladder
intraluminal filling defects
obstructions within the bladder lumen
ex. calculi, air bubbles, blood clots
air bubble appearance on double contrast study
round radiolucencies
located on periphery
calculi appearance on double contrast study
round radiolucencies
located in center
blood clot appearance on double contrast
irregularly shaped radiolucencies
located in center
intramural filling defects
obstructions extending from the mucosa
ex. mural masses
intramural mass appearance on positive contrast
broad based filling defect; contrast does not completely fill the bladder
contrast surrounds the irregular margins of the mass
extramural filling defects
obstructions from outside the urinary tract that compress the lumen
ex. neighboring organomegaly
ruptured bladder appearance on radiographs
poor serosal detail
lack of definitive bladder margins
ruptured bladder appearance on positive contrast
leakage of contrast into the peritoneal cavity
where are sublumbar lymph nodes located
lateral to aortic bifurcation, dorsal to colon and bladder
are normal sublumbar lymph nodes visible
yes/no - can be ID’d but difficult to find
what causes enlarged sublumbar lymph nodes
neoplasia or hind limb draining defects
can be partially mineralized
is the urethra normally visible on radiographs
NO - need contrast or presence of an irregular mineral opacity in the lumen to visualize
urethrogram
injection of contrast into the distal urethra
often causes air bubbles (normal artifact) - take sequential radiographs while filling with contrast to see if air bubble moves (if still there - could be radiolucent stone)
female urethra
short, exits directly caudal into the vestibule
vaginourethrogram
injects contrast into the vestibule to highlight the urethra and the vagina
fills the urethra to the bladder
fills the vagina to the uterine stump (spayed animals)
male urethra
long; extends caudally then wraps around cranial-ventrally to exit through os penis
pelvic urethra
proximal part of the urethra located in pelvic canal
membranous urethra
middle part of the urethra
curves over the pubis
penile urethra
distal part of the urethra
travels through the perineum to os penis
appearance of urethral calculi on urethrogram
discrete, round radiolucencies that distend the urethral wall
appearance of neoplasia on urethrogram/vaginourethrogram
irregular, poorly defined mucosal margins
prostatic neoplasia - irregular pelvic urethra
urethral strictures
narrowing of the urethral lumen causing partial obstruction
causes of urethral strictures
previous stones or other inflammation that causes a focal area of fibrosis
ruptured urethra - causes and appearance on urethrogram
caused by pelvic fractures
appears as contrast leakage from urethra
