Introduction to Luminal GI imaging

Question 1

Ionising radiation imaging types

Answer 1

Plain film/x-ray
CT
Fluoroscopy
Nuclear Medicine

Question 2

Non-ionising imaging types

Answer 2

MRI

US

Question 3

Planes

Answer 3

Coronal/Frontal (anterior posterior)
Sagittal (left right)
Transverse/Axial (perpendicular to length)

Question 4

Plain Film

Answer 4

X-ray

Question 5

Fluoroscopy

Answer 5

Uses contrast
Barium swallow
Double contrast - from ingested (white areas) and air (dark)

Question 6

CT

Answer 6

Porto-venous phase - inject contrast and wait 60secs for it to reach portal vein to go to liver
Also non-contrast
Arterial phase CT - reached arteries but not portal vein

Question 7

When not to give renal contrast

Answer 7

Creatinine >140 in women or >160 women then do not

Question 8

Portovenous CT

Answer 8

Standard CT contrast

Abdominal viscera

Question 9

CT none contrast use

Answer 9

CT KU

Question 10

Angiogram

Answer 10

CT arterial contrast

Aorta and arteries

Question 11

Nuclear Medicine

Answer 11

Functional Imaging
Metabolism of structures vs anatomical position
Inject with radioisotope
Look at tracer uptake depending on metabolic activity

Question 12

MRI

Answer 12

Biliary tree
Kidneys
Spleen
Small bowel

Question 13

US

Answer 13

Liver
Kidney
Appendix

Question 14

GI Anatomy components

Answer 14

oropharynx
Larynx
Oesophagus and stomach
Small bowel = jejunum and ileum
Large bowel = colon and appendix
Accompanying mesenteries

Question 15

large bowel vs. small bowel differentials

Answer 15

haustrations - large bowel
small bowel majority on right of abdomen and mesentery atatches to posterior
jejunum more frequent folds and less than ileum

Question 16

Which parts of duodenum are in the retroperitoneum?

Answer 16

D2 and D3

Question 17

Retroperitoneal Structures

Answer 17

Duodenum - D2,3
Ascending colon
Descending colon
Rectum
Adrenal Glands
Aorta
IVC
Pancreas except tail
ureters
Kidneys

Question 18

Intraperitoneal Structures

Answer 18

Stomach
Duodenum = D1,D4
Jejunum
Ileum
Transverse colon
Sigmoid colon

Question 19

What does the choice of imaging depends on?

Answer 19

Clinical question
Clinical status of patient
Body habitus
Availability
Expertise
Pregnancy

Question 20

Common acute pathologies requiring scans

Answer 20

Bowel obstruction
bowel ischaemia
Perforation
Diverticulitis
Appendicitis
IBD
GI haemorrhage
Ruptured AAA
Pancreatitis
Biliary colic
Renal colic

Question 21

Bowel obstruction/perforation imaging

Answer 21

CT

Then abdominal imaging

Question 22

Ruptured AAA imaging

Answer 22

CT acutely

US for surveillance

Question 23

IBD imaging

Answer 23

US/MRI enterography

Question 24

Renal colic imaging

Answer 24

CT KUB

Question 25

When is CT KUB used?

Answer 25

Only for renal/ureteric calculi

Question 26

Anastomatic leaks

Answer 26

CT contrast
upper GI = omnipaque contrast swallow or chest CT and oral contrast
lower GI = contrast CT and oral contrast if tolerated

Question 27

Malignant common pathologies

Answer 27

Colorectal cancer
Gastric and oesophageal cancer

Endoscopic assessment is gold standard for both first!!

Question 28

Colorectal cancer imaging

Answer 28

CT (outside rectum) and MRI (inside rectum)

Question 29

Gastric and oesophageal cancer imaging

Answer 29

CT, PET, CT, laparoscopy