Diagnostic Imaging

Question 1

give the size, shape, number, location, position, and opacity of the kidneys on radiographs

Answer 1

size:
dog: 2.5-3.5x the length of L2 on VD
cat: 2-3x the length of L2 on VD

shape:
dog: elongated bean
cat: more rounded and may see fat in renal sinus at hilus level

number: 2

location: retroperitoneal

position: right is more cranial than left

opacity: homogenous soft tissue opacity

Question 2

why is the right kidney of dogs often difficult to see on radiographs in VD?

Answer 2

it sits in the renal fossa of the liver and the liver and kidney touch, leading to effacement and loss of margins

Question 3

are normal ureters seen in plain radiographs? what can often be confused for ureters?

Answer 3

no! the deep circumflex iliac arteries are often a fake out for the ureters

Question 4

describe the urinary bladder on radiographs, including one limitation to radiography (4)

Answer 4

1. homogenous soft tissue opacity
2. ligamentous supports and adjacent mesentery contain fat that allows for visualization of bladder margins
3. thickness of bladder wall cannot be visualized since urine has the same opacity; need contrast to visualize wall thickness
4. size is highly variable based on amount of urine

Question 5

what are the 3 portions of the bladder?

Answer 5

apex: cranial
body: middle
neck: caudal

Question 6

what is special about feline urethra thanks to their large amount of abdominal fat?

Answer 6

can see a relatively long pre-pelvic part of the urethra on radiographs

Question 7

describe the urethra in females

Answer 7

short and wide

Question 8

describe the urethra in males

Answer 8

3 parts:
prostatic, membranous, and penile (beginning at os penis)

Question 9

how do you radiograph the entire urethra?

Answer 9

make sure to include a caudally collimated radiograph (butt shot)

Question 10

what are the 2 types of contrast studies for the urinary system and which parts are they used for?

Answer 10

1. kidneys: excretory urography (IV) or visualize via ultrasound
2. ureters: excretory urography
3. urinary bladder: retrograde urethrocystogram (catheter) or visualize via ultrasound
4. urethra: retrograde urethrocystogram

Question 11

give synonyms, contraindication, complications, type of contrast, and phases of excretory urography

Answer 11

synonyms: intravenous pyelogram or urogram

contraindication: dehydration

complications: very rare

contrast type: iodinated, nonionic

phases:
vascular: during injection of contrast, visualize renal vessels
nephrogram: 10-30 seconds post injection, visualize renal parenchyma
urethrogram: 3 minutes post injection, visualize renal diverticular regions, pelvis, and ureters

Question 12

what is a paddle study?

Answer 12

using a compressive devise like a wooden spoon or a paddle to improve visualization of the urinary bladder, uterus, or masses in the caudal abdomen by spreading the structures out

Question 13

give the size, echogenicity, position, margin, and shape of the bladder on ultrasound

Answer 13

size: depends on amount of urine
echogenicity: anechoic (no echo) thin echogenic wall
position: caudal abdomen
margin: smooth
shape: tear drop with blind apex and pointed trigone

Question 14

what are ureteral papillae?

Answer 14

a normal ureteral insertion in the dorsal trigone area of the bladder; hard to visualize but can use dopplar to see jets of urine from ureteral peristalsis

Question 15

be able to identify the cortex, medulla, and renal pelvis on long and short axis ultrasound pictures

Answer 15

see ppt