Imaging LUT bladder and urethra Flashcards
Indications for diagnostic imaging of the urethra and urinary bladder
- abnormal urinary profile
- altered urination (dysuria, pollakiuria, haematuria)
- abdo/pelvic trauma
- caudal abdo masses
Which animals need a 3rd view of the LUT?
male dogs - caudal pelvic region to see urethra coursing ventrally
What is seen with urolithiasis?
- Change in opacity
- Dorsal deflection of the colon
4 main types of contrast studies?
- retrograde vagino-urethrogram
- contrast cystography
- double contrast cystograpy
- contrast cystography (pneumocystogram) air, CO2, nitrous oxide
Pateitn preparation for LUT contrast studies?
> survey rads for baseline ALWAYS
- colon empty? enema
GA
Urine sampling before contrast admin (can be bacteriostatic too if trying to culture)
± 2-5ml 2% lidocaine (if expanding the bladder)
contrast media
- Co2 ,N2O (not room air as emboli can form)
- water soluble iodine based contrast media
Outline pneumocystogram process
- foley catheter retrograde -> bladder
- 4-11ml/kg gas
- views obtained (lateral L and R) VD
When is pneumocystogram contraindicated?
Potential ruptured bladder (use + contrast)
Outline process of + contrast study
- 4-11ml/kg water soluble iodine based
- undiluted contrast if rupture suspected
- dilute to 25% conc with saline for other indications
- prefill catheter with contrast medium
> orthogonal views
How can under and over distension be noted?
- wimpy looking deflated balloon
v. - overdistended round shape (loss of pear shape)
(beware can ruptrue/retrograde fill kidneys gas in pelvis)
What is negative contrast study particularly useeful for diagnosing?
> bladder location
- pelvic bladder (sitting on top of pubic bone not hanging over the edge)
- pdf inontinence
- could be herniation
Outline process of double contrast cystogram
- empty bladder
- small volume non-dilute iodine based contrast medium
- add gas (CO2, nitrous oxide) 4-11ml/kg
- reposition patient (ROLL!)
> L and R lateral, VD ± oblique views
What are double contrast cystograms helpful for?
Finding…
> uroliths
- sit in middle of contrast puddle (gravity dependent)
- circular
> blood clots
- not very heavy so swim on top of puddle
- more variable shapes
> air bubbles/mural lesions
- bubbles go towards rim/edges of pelvis on top of puddle
- mural lesions also cause filling defects in same position
- regular v irregular edges (bubble v mass)
What is the positive contrast retrograde vagino-urethrocystogram useful for?
- urethra
- vagina
- ± urinary bladder
Procedure of retrograde vagino-urethro-cystogram
- catheter (foley for females with balloon tip)
- clamps
- 10-15ml (dogs) 5-10ml (cats) water soluble contrast medium
> lateral views when injecting last 2-3mls - VD not very helpful
What can be seen on + retrograde vagino-urethro-cystogram?
> filling defects - intraluminal lesion - mural lesion - extramural lesion > extravasation of contrast - rupture - fistula - diverticula > abnormal shape, position or number - strictures - displacement - suplication