Diagnostic imaging - abdomen

Question 1

When is serosal detail poor?

Answer 1

If no fat
Young
Peritonitis
Fluid
Neoplasia

Question 2

Where is the spleen on radiograph?

Answer 2

Visible in dog on both progections, less visible on cat lateral
Head caudal to stomach on left
Tail usually mid ventral abdomen

Question 3

What is the most common cause of ventral midabdominal mass?

Answer 3

Splenic mass

Question 4

What can you use to assess liver size?

Answer 4

Gastric axis - usually parallel to ribs, perpendicular to spine

Question 5

What are the differentials for a small liver?

Answer 5

Portosystemic shunt
Cirrhosis - end stage liver disease
Chronic hepatitis

Question 6

What are the differentials of a large liver?

Answer 6

Acute hepatitis
Endocrine hepatopathy
Congestion
Focal mass lesion

Question 7

What conditions can you identify from the position of the stomach on plain radiographs?

Answer 7

Hiatal hernia
Gastro-oesophageal insussusception
Diaphragmatic rupture
Dilation and volvulus

Question 8

How do you tell if the small intestine is dilated?

Answer 8

Ratio of SI width to height of mid-body of L5
If ratio is less than 1.4 its no likely to be obstructed
If ratio is more than 2.4 it is very likely to be obstructed

Question 9

What does a gravel sign mean?

Answer 9

Sign of chronic partial SI obstruction

Question 10

Where are the colons anatomical positions?

Answer 10

Ascending - right mid-abdomen
Transverse - crosses caudal to stomach
Descending - left abdomen
Rectum - in pelvic canal

Question 11

In dogs what should the colonic width not exceed?

Answer 11

3x normal SI
Shouldnt be longer than the body of L7

Question 12

What is the definition of contrast media?

Answer 12

Agents that are more or less opaque than surrounding tissue

Question 13

What does contrast media do?

Answer 13

Delineate organs/cavities within the body
To see structures that arent usually visible
To gain more info about structures

Question 14

What is a positive contrast? What are some examples?

Answer 14

High atomic number
Eg. barium, iodine
Appear white on radiograph

Question 15

What is a negative contrast? What are some examples?

Answer 15

Low density
Eg. Gases - air, CO2
Black on radiograph

Question 16

When is barium used?

Answer 16

In the GI tract
Inert, cheap, palatable
NOT IV

Question 17

When is iodine used?

Answer 17

Urinary tract - renal excretion
Injected IV

Question 18

What are the two types of iodine contrast? Which is safer?

Answer 18

Ionic
Non ionic - safer

Question 19

What are the advantages of negative contrast media (air or CO2)?

Answer 19

Cheap
Simple to use
Relatively safe
Can combine with positive contrast agents eg. double contrast in bladder

Question 20

What are the disadvantages of negative contrast media?

Answer 20

Very small risk of air embolism
Poor mucosal detail, less contrast

Question 21

What are the indications for a barium swallow?

Answer 21

Shows pharynx and oesophagus:
Dysphagia
Regurgitation

Question 22

When do you not use barium?

Answer 22

If suspected rupture - use iodinated contrast instead
If risk of aspiration

Question 23

What is the normal appearance of a cat oesophagus?

Answer 23

Herringbone appearance to smooth muscle of lower oesophagus

Question 24

When should you only use liquid barium?

Answer 24

In a barium follow through study - by mouth or stomach tube

Question 25

How do you do a barium follow through study?

Answer 25

Radiographs taken immediately after liquid barium swallowed
Then at intervals
Final image at 24 hours or when all barium is in colon

Question 26

What are the indications for a barium GIT study?

Answer 26

Persistent recurrent vomiting
Or haematemesis
If palpable mass
If suspect anomaly on plain radiograph

Question 27

What complications can barium cause?

Answer 27

Granulomatous pneumonia if aspirated

Question 28

What are normal GI findings from contrast?

Answer 28

Duodenal pseudoulcers - indentations in lymphoid tissue
String of pearls appearance - from peristalsis

Question 29

What do you use to evaluate the large intestine?

Answer 29

Barium enema - liquid barium infused into rectum post enema
Messy
Difficult to interpret - just do endoscopy