Radiographs: Lower Urinary Tract

Question 1

where is the bladder located on lateral and V/D projections

Answer 1

ventral to the colon
midline (covered by vertebral column) on V/D

Question 2

compression radiographs

Answer 2

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

Question 3

what stones are visible on radiographs

Answer 3

struvite or Ca oxalate

Question 4

positive contrast cystogram

Answer 4

injecting the bladder with iodinated contrast to evaluate bladder margins and leakage

Question 5

double contrast cystogram

Answer 5

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

Question 6

intraluminal filling defects

Answer 6

obstructions within the bladder lumen

ex. calculi, air bubbles, blood clots

Question 7

air bubble appearance on double contrast study

Answer 7

round radiolucencies
located on periphery

Question 8

calculi appearance on double contrast study

Answer 8

round radiolucencies
located in center

Question 9

blood clot appearance on double contrast

Answer 9

irregularly shaped radiolucencies
located in center

Question 10

intramural filling defects

Answer 10

obstructions extending from the mucosa

ex. mural masses

Question 11

intramural mass appearance on positive contrast

Answer 11

broad based filling defect; contrast does not completely fill the bladder

contrast surrounds the irregular margins of the mass

Question 12

extramural filling defects

Answer 12

obstructions from outside the urinary tract that compress the lumen

ex. neighboring organomegaly

Question 13

ruptured bladder appearance on radiographs

Answer 13

poor serosal detail
lack of definitive bladder margins

Question 14

ruptured bladder appearance on positive contrast

Answer 14

leakage of contrast into the peritoneal cavity

Question 15

where are sublumbar lymph nodes located

Answer 15

lateral to aortic bifurcation, dorsal to colon and bladder

Question 16

are normal sublumbar lymph nodes visible

Answer 16

yes/no - can be ID’d but difficult to find

Question 17

what causes enlarged sublumbar lymph nodes

Answer 17

neoplasia or hind limb draining defects

can be partially mineralized

Question 18

is the urethra normally visible on radiographs

Answer 18

NO - need contrast or presence of an irregular mineral opacity in the lumen to visualize

Question 19

urethrogram

Answer 19

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)

Question 20

female urethra

Answer 20

short, exits directly caudal into the vestibule

Question 21

vaginourethrogram

Answer 21

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)

Question 22

male urethra

Answer 22

long; extends caudally then wraps around cranial-ventrally to exit through os penis

Question 23

pelvic urethra

Answer 23

proximal part of the urethra located in pelvic canal

Question 24

membranous urethra

Answer 24

middle part of the urethra
curves over the pubis

Question 25

penile urethra

Answer 25

distal part of the urethra
travels through the perineum to os penis

Question 26

appearance of urethral calculi on urethrogram

Answer 26

discrete, round radiolucencies that distend the urethral wall

Question 27

appearance of neoplasia on urethrogram/vaginourethrogram

Answer 27

irregular, poorly defined mucosal margins

prostatic neoplasia - irregular pelvic urethra

Question 28

urethral strictures

Answer 28

narrowing of the urethral lumen causing partial obstruction

Question 29

causes of urethral strictures

Answer 29

previous stones or other inflammation that causes a focal area of fibrosis

Question 30

ruptured urethra - causes and appearance on urethrogram

Answer 30

caused by pelvic fractures

appears as contrast leakage from urethra