imaging the small and large intestine

Question 1

what other structure can pancreatic cancer grow into

Answer 1

the duodenum

Question 2

what landmarks are the beginning and end of the small intesting

Answer 2

beginning - DJ flexure
end - ileocaecal valve

Question 3

what is the small intestine attached to the posterior wall by

Answer 3

mesentery

Question 4

what is the blood supply to the small intestine

Answer 4

Superior Mesenteric Artery

Question 5

what organs are in the foregut (7)

Answer 5

1. oesophagus
2. stomach
3. liver
4. gallbladder
5. bile ducts
6. pancreas
7. proximal duodenum

Question 6

indications for intestinal imagining (4)

Answer 6

1. previous small bowel obstruction admission
2. unexplained iron deficiency anaemia w normal colonoscopy and OGD
3. malabsoption
4. unexplained pain/diahorrea/weight loss (+ raised inflammatory markers)

Question 7

what imaging can be done for suspected crohn’s disease (4)

Answer 7

1. barium studies
2. ultrasound
3. CT enterography
4. MR enterography

Question 8

what is “fat wrapping” in crohn’s disease

Answer 8

abdominal fat migrates to the wall of the inflamed small intestines - can be seen on imaging

Question 9

what contrast is given in MR eneterography

Answer 9

mannitol - it is hyperosmolar and so pulls fluid into the bowels

Question 10

inidications for large bowel imaging (5)

Answer 10

1. change in bowel habits
2. PR bleeding
3. immunodeficency
4. palpable mass
5. carcinoma/ polyps found

Question 11

what are bowel polyps

Answer 11

benign hyperplastic growth in the bowel (can occur in any hollow organ)

Question 12

polyp size and risk of malignancy

Answer 12

1cm - 10% risk of malignancy
2cm - 50% risk of malignancy

Question 13

evolution of colon cancer phases (5)

Answer 13

can take years to develop
1. normal epithelium
2. early adenoma
3. intermediate adenoma
4. late adenoma
5. carcinoma

Question 14

at what age is colon cancer screened for

Answer 14

55yro

Question 15

what is seen on a colitis colonoscopy

Answer 15

1. purulent exudate
2. loss of vascular pattern
3. ulceration
4. erosions
5. pseudopolyps

Question 16

what is diverticular disease

Answer 16

muscle spasm in the colon in the presence of diverticula causes abdominal pain and disturbance of bowel function without inflammation

Question 17

common cause for diverticular disease

Answer 17

low fibre diets (e.g. western diets) -> results in bowel weakening

Question 18

4 imaging options for suspected colon cancer

Answer 18

1. colonoscopy
2. flexible sigmoidoscopy
3. colon CT
4. CT abdo + pelvis

Question 19

3 imaging options for suspected colitis

Answer 19

1. rigid sigmoidoscopy
2. colonosocpy
3. CT

Question 20

colonoscopy (4) vs CTC (5)

Answer 20

colonoscopy:
1. requires bowel prep
2. failure to complete
3. able to perform biopsies
4. gold standard

CTC:
1. minimal preparation
2. usually able to visualise caecum
3. no biopsy possible
4. technique can be widely disseminated
5. images can be reviewed

Question 21

sigmoidoscopy vs colonoscopy

Answer 21

colonoscopy - entire length of colon
sigmoidoscopy - only examines the lower third

Question 22

small bowel obstruction radiological findings (3)

Answer 22

1. central stacked bowels 3.5-6cm in diameter
2. markings cross lumen diameter
3. little gas in large bowel

Question 23

5 causes of small bowel obstruciton

Answer 23

1. adhesions/bands
2. hernias
3. crohn’s disease
4. infiltrating neoplasms
5. intussusception (when one part of the intestine slides into another part, like a collapsible telescope)

Question 24

large bowel obstruction radiological findings

Answer 24

1. peripheral air filler loops >7cm in diameter
2. haustra do not cross lumen diameter
3. dilated small bowel (not always, depends on competency of ileo-caecal valve

Question 25

causes of large bowel obstruction

Answer 25

1. tumours
2. volvulus (twisting)
3. diverticular strictures