Week 10 - imaging of the GI tract

Question 1

From which view should an AXR be taken?

Answer 1

-A->P

Question 2

What is the structure for interpreting an AXC?

Answer 2

• Air/gas
• Bowel
• Calcification and bones

Question 3

When would the bowel not be visible?

Answer 3

-If it was entirely full of fluid

Question 4

What are valvulae conniventes?

Answer 4

-Lines across the entire wall of the small intestine

Question 5

How is the small intestine differentiated from the large on AXR?

Answer 5

• large -> haustra do not go all the way across

- small -> valvulae conniventes go all the way across

Question 6

An obstruction is likely present when a small bowel loop is bigger than what size?

Answer 6

-3cm

Question 7

An obstruction is likely present when a large bowel loop is bigger than what size?

Answer 7

-9cm

Question 8

How does sigmoid volvulus often look on an AXR?

Answer 8

-Coffee bean sign in left iliac fossa

Question 9

What causes toxic megacolon? How does it present on AXR?

Answer 9

• Infection

- Chronically dilated with pseudopolyps

Question 10

Lead pipe colon is a sign of what?

Answer 10

-UC

Question 11

What is thumb printing?

Answer 11

-Odematous thickened haustra

Question 12

What soft tissues should be identified on an AXR except bowels?

Answer 12

-Liver, spleen, stomach, kidneys

Question 13

When would you do an erect CXR?

Answer 13

-Pneumoperitoneum

Question 14

Name 4 possible causes of pneumoperitoneum

Answer 14

• Peptic ulcer
• Diverticular
• Tumour
• Obstruction

Question 15

What is the major disadvantage to CT?

Answer 15

-Very high dose of radiation

Question 16

What does CT require?

Answer 16

-IV contrast and knowledge of anatomical levels

Question 17

MRIs have no radiation and give the best spatial resolution. Why is it then that they are not always used?

Answer 17

• Time consuming

- Anything which moved proves problematic eg small bowel, unwell patient

Question 18

What is the major disadvatage to abdominal USS?

Answer 18

-Highly user dependant

Question 19

What are the advatages to abdominal USS?

Answer 19

• Cheap
• Fast
• Portable

Question 20

What is indicative of chronic prancreatitis on AXR?

Answer 20

-Retroperitoneal calcificaton

Question 21

Describe a barium swallow

Answer 21

• Oesophagus visualised as barium is swallowed in upright and prone positions
• Allow visualisation of motility abnormalities and anatomical lesions

Question 22

When is a barium meal used?

Answer 22

-To visualise stomach and duodenum

Question 23

When is a barium follow through used?

Answer 23

-To visualise small bowel

Question 24

When is the best time to use USS?

Answer 24

-Fluid filled lesions

Question 25

Name the most common reasons for a request of AXR

Answer 25

• Acute pain
• Obstruction
• Renal colic