JC Block C - Diagnostic Radiology - Gastrointestinal

Question 1

Advantages and Limitations of AXR for GI imaging

Answer 1

Question 2

Compare small bowel and large bowel on AXR:

Placement 
Mucosa 
Content 
Caliber 
Bowel gas 
Fluid

Answer 2

Question 3

Normal GIT structures with gas within

Answer 3

Stomach
2-3 loops of non-distended small bowel
Rectum and sigmoid colon

Question 4

Describe picture

Answer 4

> 2-3 fluid levels in small bowel
DIlated small bowel >3.5cm

Indicates IO

Question 5

Abnormality?

Answer 5

Dilated Large bowel >5cm

Large bowel IO

Question 6

Abnormality?

Answer 6

Pneumoperitoneum:
 Free gas under diaphragm
 Rigler sign (can see both sides of the thin bowel wall clearly due to presence of intra- and extraluminal gas
 Falciform ligament sign (aka Silver sign): falciform ligament outlined with free abdominal gas

Question 7

Barium and contrast studies

Functions

Indications for different contrasts

Answer 7

Functions:
 Coat and show bowel mucosa
 Dynamic study (assess bowel motility)
 Demonstrate obstruction and leaks

Indications:
Barium double contrast studies - better visualization of the mucosal pathology e.g. IBD
Water-soluble contrast for perforation/ anastomotic leak (c/i barium peritonitis)

Question 8

4 types of barium studies

Answer 8

Question 9

Indications for barium swallow

Answer 9

1. Difficulty swallowing (dysphagia)
2. Suspect tumors, strictures, ulcers, esophagitis (inflammation)
3. Video fluroscopic swallowing exam - esophagus motility problems

Question 10

Label

Answer 10

Question 11

Label

Answer 11

Question 12

Indications for barium meal

Answer 12

Indications:
 Dyspepsia (indigestion)
 Weight loss (?malignancy)
 Upper abdominal mass
 Iron deficiency anaemia (GI hemorrhage)
 Partial upper GIT obstruction (e.g. gastric outlet obstruction)

Question 13

Compare SB follow through and SB enema

Procedure
Contrast
Pro
Cons

Answer 13

Question 14

Indications for barium enema

Answer 14

 Alteration in bowel habit
 Chronic diarrhea/ constipation
 Rectal bleeding
 Abdominal pain
 Suspected abdominal mass
 Obstruction

Question 15

Label

Answer 15

Question 16

CT abdomen

Advantages

Answer 16

1) Fast imaging
2) Extra-colonic assessment E.g. colorectal cancer staging
3) Multi-planar reconstruction
4) Excellent anatomical correlation

Question 17

Lesion

Answer 17

Colitis – ulcerative colitis

Marked thickening of mucosa,
reducing the normal haustra pattern

Question 18

Lesion

Answer 18

Enteritis secondary to ischemia:
small bowel wall abnormally
thickened and enhancing

Question 19

Lesion

Answer 19

Perforation: CT is sensitive for small pocket of gas in intraperitoneal cavity

Question 20

Lesion

Answer 20

Distended small bowel loops

Small bowel obstruction

Question 21

Lesion

Answer 21

Large bowel obstruction

Distended and filled with fecal
material

Question 22

Signs and causes of SB obstruction

Answer 22

Question 23

Indications for GIT angiogram

Modalities

Answer 23

 Acute/ chronic ischemia
 Aneurysm
 Crohn’s disease
 Gastrointestinal bleeding

Mesenteric CT angiogram
Angiography (allows intervention e.g. trans-arterial embolization)

Question 24

Indication of USG for GIT exam

Answer 24

Lack of radiation  useful in paediatric group

Selected conditions:
 Appendicitis
 Intussusception
 Pelvic abscess from bowel perforation

Question 25

Indications for MRI and PET/CT scans for GIT

Answer 25

MRI:
Cancer staging and treatment strategy
MR Enterography - for strictures and inflammatory enhancement

PET/CT:
Cancer staging, chemo treatment response

Question 26

Case 1:
 F/75
 Presented with weight loss and dysphagia
 Refused endoscopy
 FBC shows microcytic anaemia

Imaging? Features?

Answer 26

Barium swallow:
 Stricturing at distal esophagus before coming into stomach

Features suggesting a malignant stricture:
 Irregular outline
 ‘Shouldering’ sign
 Proximal dilatation of esophagus

should be followed up with endoscopy

DDx: achalasia (smooth tapering of distal esophagus)

Question 27

Role of imaging in oesophageal cancer:

Answer 27

 Staging
 Treatment planning (e.g. whether undergo upfront surgery or preoperative chemoirradiation)
 Surgical planning
 Follow-up/ assessment of treatment response (chemotherapy)

Question 28

Case 2:
 M/65
 Fresh PR bleeding and weight loss
 FBC shows microcytic anaemia
 Could not tolerate endoscopy (colonoscopy)

Imaging and features

Answer 28

Barium enema (double contrast – barium and air):
 Short segment of irregular stricturing - apple core appearance

Follow up with CT e.g. CT colonography (CTC), Staging with MRI

colorectal cancer

Question 29

Role of imaging in colorectal cancer

Answer 29

Screening (e.g. CT colonography (CTC)

Staging (e.g. MRI)

Treatment planning/ stratification

Surgical planning

Follow-up/ assessment of treatment response

Question 30

Case 3:
 F/75 presented to A&E
 Confused
 Poor historian
 Intermittent abdominal distension and pain

Imaging and feature?

Answer 30

AXR:
 Distended bowel loop in mid abdomen  obstruction and dilatation
 Dx: sigmoid volvulus

Question 31

Imaging features of sigmoid vs cecal volvulus

Answer 31

Question 32

Case 4:
 M/80
 Presented with 4 days history abdominal pain and distention
 PHx appendicitis. Nil else

Imaging and finding?

Answer 32

AXR:
 Multiple loops of distended small bowel
 Paucity of large bowel
 Multiple air-fluid levels (arrows)
 On the left, bowel gas extends beyond pelvic ring (important to include this area in radiology)

 Small bowel obstruction due to strangulated inguinal hernia

Question 33

Case 5:
 F/32 banker presented to A&E
 No PHx
 Sudden onset severe abdominal pain
 On examination: perintonitic

Imaging and Feature

Answer 33

AXR: pneumoperitoneum (recall falciform ligament sign, Rigler sign)

 Suspect perforation  follow up with water-
soluble contrast upper GI study:

Question 34

Case 6:
 M/30
 Previously fit and well
 A few days history of low grade fever and vague abdominal pain
 Presented with A&E with localised severe right iliac fossa pain

Answer 34

CT abdomen and pelvis:
 Appendicolith: calculus obstructing appendiceal orifice  distal
obstruction and dilatation of appendix
 Right para-colic gutter collection
 Dx: appendicitis

Question 35

Case 7:
 F/34 British
 Presented to A&E with bloody diarrhoea and fever (acute on chronic presentation)
 Intermittent diarrhoea and abdominal pain for a year
 Known history of UC

Imaging and feature

Answer 35

AXR on admission:
 Grossly distended and featureless colon (esp transverse, descending and sigmoid)
 Toxic megacolon (at risk of perforation)