Introduction to Luminal GI imaging Flashcards
Ionising radiation imaging types
Plain film/x-ray
CT
Fluoroscopy
Nuclear Medicine
Non-ionising imaging types
MRI
US
Planes
Coronal/Frontal (anterior posterior)
Sagittal (left right)
Transverse/Axial (perpendicular to length)
Plain Film
X-ray
Fluoroscopy
Uses contrast
Barium swallow
Double contrast - from ingested (white areas) and air (dark)
CT
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
When not to give renal contrast
Creatinine >140 in women or >160 women then do not
Portovenous CT
Standard CT contrast
Abdominal viscera
CT none contrast use
CT KU
Angiogram
CT arterial contrast
Aorta and arteries
Nuclear Medicine
Functional Imaging
Metabolism of structures vs anatomical position
Inject with radioisotope
Look at tracer uptake depending on metabolic activity
MRI
Biliary tree
Kidneys
Spleen
Small bowel
US
Liver
Kidney
Appendix
GI Anatomy components
oropharynx Larynx Oesophagus and stomach Small bowel = jejunum and ileum Large bowel = colon and appendix Accompanying mesenteries
large bowel vs. small bowel differentials
haustrations - large bowel
small bowel majority on right of abdomen and mesentery atatches to posterior
jejunum more frequent folds and less than ileum
Which parts of duodenum are in the retroperitoneum?
D2 and D3
Retroperitoneal Structures
Duodenum - D2,3 Ascending colon Descending colon Rectum Adrenal Glands Aorta IVC Pancreas except tail ureters Kidneys
Intraperitoneal Structures
Stomach Duodenum = D1,D4 Jejunum Ileum Transverse colon Sigmoid colon
What does the choice of imaging depends on?
Clinical question Clinical status of patient Body habitus Availability Expertise Pregnancy
Common acute pathologies requiring scans
Bowel obstruction bowel ischaemia Perforation Diverticulitis Appendicitis IBD GI haemorrhage Ruptured AAA Pancreatitis Biliary colic Renal colic
Bowel obstruction/perforation imaging
CT
Then abdominal imaging
Ruptured AAA imaging
CT acutely
US for surveillance
IBD imaging
US/MRI enterography
Renal colic imaging
CT KUB
When is CT KUB used?
Only for renal/ureteric calculi
Anastomatic leaks
CT contrast
upper GI = omnipaque contrast swallow or chest CT and oral contrast
lower GI = contrast CT and oral contrast if tolerated
Malignant common pathologies
Colorectal cancer
Gastric and oesophageal cancer
Endoscopic assessment is gold standard for both first!!
Colorectal cancer imaging
CT (outside rectum) and MRI (inside rectum)
Gastric and oesophageal cancer imaging
CT, PET, CT, laparoscopy
