Imaging LUT bladder and urethra

Question 1

Indications for diagnostic imaging of the urethra and urinary bladder

Answer 1

• abnormal urinary profile
• altered urination (dysuria, pollakiuria, haematuria)
• abdo/pelvic trauma
• caudal abdo masses

Question 2

Which animals need a 3rd view of the LUT?

Answer 2

male dogs - caudal pelvic region to see urethra coursing ventrally

Question 3

What is seen with urolithiasis?

Answer 3

• Change in opacity

- Dorsal deflection of the colon

Question 4

4 main types of contrast studies?

Answer 4

• retrograde vagino-urethrogram
• • contrast cystography
• double contrast cystograpy
• • contrast cystography (pneumocystogram) air, CO2, nitrous oxide

Question 5

Pateitn preparation for LUT contrast studies?

Answer 5

> 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

Question 6

Outline pneumocystogram process

Answer 6

• foley catheter retrograde -> bladder
• 4-11ml/kg gas
• views obtained (lateral L and R) VD

Question 7

When is pneumocystogram contraindicated?

Answer 7

Potential ruptured bladder (use + contrast)

Question 8

Outline process of + contrast study

Answer 8

• 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

Question 9

How can under and over distension be noted?

Answer 9

• wimpy looking deflated balloon
  v. - overdistended round shape (loss of pear shape)
  (beware can ruptrue/retrograde fill kidneys gas in pelvis)

Question 10

What is negative contrast study particularly useeful for diagnosing?

Answer 10

> bladder location

• pelvic bladder (sitting on top of pubic bone not hanging over the edge)
• pdf inontinence
• could be herniation

Question 11

Outline process of double contrast cystogram

Answer 11

• 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

Question 12

What are double contrast cystograms helpful for?

Answer 12

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)

Question 13

What is the positive contrast retrograde vagino-urethrocystogram useful for?

Answer 13

• urethra
• vagina
• ± urinary bladder

Question 14

Procedure of retrograde vagino-urethro-cystogram

Answer 14

• 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

Question 15

What can be seen on + retrograde vagino-urethro-cystogram?

Answer 15

> filling defects
- intraluminal lesion
- mural lesion 
- extramural lesion 
> extravasation of contrast
- rupture
- fistula
- diverticula
> abnormal shape, position or number 
- strictures
- displacement
- suplication

Question 16

How cna you keep the bladder paritally full with a retrograde vaginourethrocystogram?

Answer 16

• prefil contrast/saline
• 25% dilute water soluble iodine based contrast medium (dilute with saline)
• dynamic study (fluoroscpy guided)
• lateral views ± oblique

Question 17

How do the male and female retrograde urethrocystogram keep contrast in the LUT?

Answer 17

• clamps!!

Question 18

Common causes of incontinence in female dogs?

Answer 18

• strictures in vaginal area

Question 19

What causes of urethral blockage cause anuria?

Answer 19

• stones (commonly in penile urethra or pelvic flexure)
• bubbles!! (can move by injecting contrast)
• haematoma
• tumour
  > look for filling defect

Question 20

What types of neoplasia are common in LUT

Answer 20

• tasnitional cell carcinoma
• commonly in trigone
• esp ureterovesicular junction
• can arise from urethra

Question 21

How would a urethral neoplasia appear?

Answer 21

Abnormal filling defect on retrograde vaginourethrocystogram

Question 22

How thick shoudl the baldder wall be on ultrasound?

Question 23

When would thickened bladder wall be seen?

Answer 23

• TCC

- cystitis

Question 24

What types of bladder neoplasia occours? What should also be assessed on ultrasound?

Answer 24

• TCC (trigone) most common
• LSA
• leiomyoma/sarcoma
  > assess medial iliac lymph nodes

Question 25

How are uroliths seen on ultrasound?

Answer 25

• proteinuria/crystaluria/haematuria -> starry sky speckled urine
• look for lumps on gravity dependent part of bladder (hypereachoic with dark shadow deep to them, indicates mineral cf. blood clots which look more soft tissue opacity and are not as closely adhered to the wall)