Contrast imaging of the lower urinary tract Flashcards Preview

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Flashcards in Contrast imaging of the lower urinary tract Deck (24)
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1
Q

Which views to take on xray of urethra and urinary bladder?

A
  • orthogonal view of abdomen

- lateral view of caudal/perineal region (male dog)

2
Q

Radiographic appearance - urinary bladder

A
  • variable size
  • pear shaped
  • soft tissue opacity
  • smooth margin- cuadoventral abdomen: ventral to colon, ventral to uterus/uterine stump, cranial to prostate, normally cranial to pubis
3
Q

What are the different contrast studies of urinary bladder?

A
  • retrograde (vagino-) urethrography
  • positive contrast cystography
  • double contrast cystography
  • negative contrast cystography (pneumocytography)
4
Q

Outline patient prepartion of contrast studies

A
  • survey radiographs (colon empty? –> enema)
  • GA
  • urine sampling prior to contrast administration
    +/- 2-5ml 2% lidocaine
  • contrast media (CO2, nitrous oxide vs. water soluble I2 based contrast media)
5
Q

Outline a pneumocytsogram

A
  • foley catheter inserted retrograde into the urinary bladder
  • 4-11ml/kg gas (CO2, NO, room air)
  • lateral (L and R) and VD
6
Q

Why be careful doing a pneumocytsogram of animal with inflamed bladder

A

inflamed bladders don’t distend as much as normal bladders so care not to rupture!

7
Q

Risks of overdistending bladder on pneumocytsogram

A
  • rupture

- gas retrograde into ureters and renal pelvis (can bring infection up)

8
Q

What contrast media should you use if you suspect a ruptured blader?

A

positive contrast

9
Q

Describe contrast medium for cystogram

A
  • 4-11ml/kg water soluble I2 based
  • undiluted contrast if suspected rupture
  • dilute to 25% concentration with saline for other indications
  • prefill catheter with contrast medium
  • VIEWS: lateral (L and R) and VD views
10
Q

Procedure - double contrast cystogram

A
  • empty urinary bladder
  • small volume non-diluted I2 based contrast medium
  • add gas (CO2, NO) at 4-11ml/kg
  • reposition patient (‘roll’)
  • VIEWS: L and R lateral, VD, +/- oblique views
11
Q

Ddx - double contrast studies

A
  • urolith (in middle of contrast puddle)
  • blood clot (at rim of contrast puddle, give odd shape to edge)
  • air bubble/ mural lesions (rim of contrast, bubbles - smal, regular outline; mural lesion - small to large, irregular outline)
12
Q

Uses - positive contrast retrograde (vagino-) urethro-cystogram

A
  • urethra
  • vagina
    +/- urinary bladder
13
Q

Method - positive contrast study, retrograde (vagino-) urethro-cystogram

A
  • catheter (foley for females with balloon tip)
  • clamps
  • 10-15ml water soluble contrast medium (dogs), 5-10ml in cats
  • VIEWS: lateral views when injecting the last 2-3ml
14
Q

Radiographic findings - positive contrast retrograde (vagino-) urethro-cystogram

A
  • FILLING DEFECTS: lesion - intraluminal, mural, extramural
  • EXTRAVASATION OF CONTRAST: rupture, fistula, diverticula
  • ABNORMAL SHAPE, POSITION, NUMBER: strictures, displacement, duplications
15
Q

How do you keep bladder full with positive contrast retrograde (vagino_) urethro-cystogram

A
  • ideally prefill with contrast or saline
  • 25% diluted water soluble I2 based contrast (dilute with saline)
  • dynamic study )ideally fluoroscopy guided)
  • Lateral views (+/- oblique)
16
Q

What is a positive contrast regtrograde (vagino-) urethrocystogram called?

A

retrograde urethro-cystogram

17
Q

What is the ‘urinary extravaganza’?

A
  • full urinary work up for incontinence
    1. IVU
    2. cystogram (negative –> double –> positive)
    3. retrograde vagino-urethrocystogram
18
Q

Ddx - obstruction of urethra

A
  • air bubble
  • urinary calculi
  • haematoma
  • blood clot
  • tumour
19
Q

How to differentiate air bubbles from urolithiasis?

A
  • BUBBLES: easy to move, ovoid

- CALCULI: favourite locations are penile urethra and pelvic flexure of urethra

20
Q

Main locations of TCC

A
  • trigone
  • urethra
  • males - prostatic urethra
21
Q

What is the shape of the uterine stump on retrograde vagino-urethrogram?

A

spoon-shaped

22
Q

Describe ultrasound of urinary bladder

A
  • wall
23
Q

How do you differentiate urinary stones from blood clots on ultrasound?

A
  • STONES: gravity dependent side, hyperechoic, have a dark shadow ‘below’ them d/t mineralisation of stones preventing ultrasound waves passing through properly
  • BLOOD CLOT: off to side, appearance of soft tissue, not on wall but separate from it
24
Q

Indications - diagnostic imaging of urethra and urinary bladder

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