GI: Imaging Flashcards Preview

ESA 3 > GI: Imaging > Flashcards

Flashcards in GI: Imaging Deck (14)
Loading flashcards...
1
Q

Why would you request an abdominal xray?

A
  • acute abdominal pain
  • small or large bowel obstruction
  • acute exacerbation of IBD
  • renal colic (although CT now first in line)
2
Q

What is a systematic approach to assessing an abdo xray?

A

A - air/gas
B - bowel
C - calcification (bones and stones)

3
Q

How do you differentiate the small bowel from the large bowel on an abdo xray?

A

The small bowel has a central position whereas the large bowel is at the periphery
The small bowel has valvulae conniventes that cross the entire wall whereas the large bowel just has haustra

4
Q

What is the 3 6 9 rule of identifying bowel obstruction?

A

Small bowel dilation is >3cm
Large bowel dilation is >6cm
Caecum is max 9 cm

5
Q

How does small bowel obstruction present?

A

Vomiting (early)
Mild distension
Absolute constipation (late)
Colicky pain

6
Q

What can cause small bowel obstruction?

A

Adhesions following surgery
Hernias
Tumours
Inflammation

7
Q

How does large bowel obstruction present?

A

Vomiting (late and faeculant)
Significant distension
Colicky pain
Absolute constipation

8
Q

What can cause large bowel obstruction?

A
Colorectal carcinoma 
Diverticular stricture
Hernia
Volvulus
Pseudo-obstruction
9
Q

What is a volvulus?

A

Twisting of the bowel around its mesentery - encloses the bowel loop which can become ischaemic or perforate
Sigmoid volvulus is common

10
Q

What is toxic megacolon?

A

Acute severe colonic distension
It is usually a result of acute deterioration of UC (sometimes crohns)
There is also oedema and pseudopolyps

11
Q

What is thumb printing?

A

(google a picture)

Due to oedematous thickened haustra caused by acute inflammation (often UC)

12
Q

What is pneumoperitoneum and what are the causes?

A

Abnormal presence of gas in the peritoneum

Caused by a perforated peptic/duodenal ulcer, tumour, perforated bowel from obstruction or trauma

13
Q

What are contrast studies used for? eg barium meal

A

Contrast is used to define hollow viscera

14
Q

What are the advantages and disadvantages of CT, MRI and USS?

A

CT: good spatial resolution but high dose radiation
MRI: no radiation, good resolution but time consuming
USS: no radiation, portable, cheap but highly user dependent

Decks in ESA 3 Class (96):