contrast studies

Question 1

contrast studies

Answer 1

-contrast agent instilled into an organ to see it better
-agent at either extreme
of 5 radiographic opacities eg gas or metal opacity

Question 2

metal opacity

Answer 2

-positive contrast
-radiopaque
-iodine-based iohexol solution (omnipaque), used everywhere (IV, myelogram)
-OR barium liquid (GIT only)

Question 3

gas opacity

Answer 3

-negative contrast
-radiolucent
-agent = room air or CO2
-eg Pneumocolonogram

Question 4

biggest problem is not following directions

Answer 4

-not right dose
-not enough radiographs
-not the right indication
-remember the 6 P’s - proper prior planning prevents poor performance

Question 5

4 indications for contrast study

Answer 5

1) locaton - where is organ eg colon - pneumocolonogram
2) rupture - is contrast leaking out (called ‘extravasation’) eg ureter- excretory urogram
3) filling defect - something displacing the contrast? eg calculus in urethra- urethrogram
4) function - is organ functioning normally eg oesophagram

Question 6

cystograms

Answer 6

-3 types of but only positive contrast cystogram used today
-pneumocystogram (-ve, air) and double contrast (+ve & -ve, air & iohexol) replaced by ultrasound

Question 7

positive contrast cystogram

Answer 7

-2 indications - location (find out if bladder is part of a large caudal abdominal mass when
US not available) and rupture
-agent - iohexol
-via urinary catheter (Foley), w balloon just inside bladder

Question 8

bladder rupture

Answer 8

-large rupture - small bladder, contrast leaking into abdomen
-eg empty bladder on US, rupture can’t be seen but catheter extending cranially from bladder confirming atrogenic rupture, free fluid (urine) in the abdomen

Question 9

urethrogram

Answer 9

-2 indications - filling defect causing obstruction (calculus obstructing urethra? air bubbles
+ blood clots can look the same) and rupture (trauma)
-agent - iohexol
-instilled via Foley w balloon in the tip of the penis

Question 10

normal urethrogram

Answer 10

-prostatic, membranous, penile
-male - narrowed at prostatic urethra unless fully distended, membranous urethra distends
-female - contrast first instilled into the vagina as well

Question 11

excretory urogram

Answer 11

-iohexol injected IV
-radiographs (or CT) to watch contrast excreted in the ureters
-does not fill bladder well, so not used to assess the bladder
-kidneys seen but US replaced EU for assessment of kidneys
-3 indications - location (ectopic
ureter), rupture (trauma > haemorrhage or ruptured ureter causing fluid), filling defect (calculus obstruction may cause renal pelvis distension)

Question 12

ectopic ureter

Answer 12

-puppies w this have incontinence
-difficult to see on radiographs - referral for CT excretory urogram (CT-EU) recommended

Question 13

upper gastrointestinal barium study

Answer 13

-2 indications - function (obstruction or linear FB that can delay transit of contrast), filling defect - FB in stomach/SI
-NOT used to assess the colon
-agent - barium, iohexol can be used but $$$ & less opaque
-often look for linear FB in cats
-instilled via gastric tube or diluted and via nasogastric tube
-radiograph made 3 hrs post-barium (contrast should’ve reached colon and stomach should be empty of contrast)
-not syringed into mouth - large V and stressful

Question 14

linear foreign body

Answer 14

-most common in cats
-one end (eg yarn) anchors (often under tongue) while rest causes intestines to bunch “plicate” and tear

Question 15

pneumogastrogram - stomach

Answer 15

-2 indications - filling defect (FB), location (small amount air or barium used to determine location of an empty stomach)
-most of the time it can be seen on survey radiographs
-instilled via gastric tube or nasogastric tube

Question 16

pneumocolonogram - colon

Answer 16

-1 indication - location
-agent - room air
-instilled via a tube in the rectum

Question 17

oesophagram

Answer 17

-2 indications - function (transporting ingesta quickly to stomach), filling defect (FB)
-NOT for diffuse megaoesophgus! - dysfunction is assumed when diffusely dilated
-agent - barium, iohexol can be used but less opaque
-syringed into the mouth