Gastrointestinal

Water loading: give 5 cups (about 800 ml) during the 15 minutes before getting on the CT scanner table. 3 of these cups should be given outside awaiting the scan and 2 cups of water in the scanner room. Do not give the water too early.

Indication	Brief description	Slice thickness and reconstruction kernel	Further details of contrast timing/explanation of what the radiographers do	Abbreviation
Cancer of oesophagus, stomach, duodenum, gallbladder, pancreas and colon/rectum	CT chest, abdomen & pelvis (contrast)	1.5 mm B30f, 1.2 mm increment.	65 seconds post contrast + oral water as above	CT CAP + c + oral water
Anal cancer	CT abdomen & pelvis (contrast)	1.5 mm B30f, 1.2 mm increment.	65 seconds post contrast	CT abdomen and pelvis + c
Colorectal Ca? Including if failed or refused colonoscopy	CT colonography	1.5 mm B30f, 1.2 mm increment.	See specific guidance	CT colonography
Active GI bleeding	Pre/arterial/delayed abdomen and pelvis	1.5 mm B30f, 1.2 mm increment.	Pre, arterial and 90 sec bolus tracked as described below	CT angio triple phase abdomen (90 second)
Mesenteric ischaemia	Pre/arterial/PV abdomen and pelvis	1.5 mm B30f, 1.2 mm increment.	Pre, arterial and 65 sec bolus tracked as described below	CT angio triple phase abdomen (65 second)
Acute abdominal pain (diverticulitis, appendicitis, perforation, obstruction, GB perforation, abdominal or pelvic collection, etc)	PV abdomen and pelvis	1.5 mm B30f, 1.2 mm increment.	65 seconds	CT abdomen and pelvis + c
Neuroendocrine tumour including carcinoid	CT Chest, abdomen and pelvis + arterial phase abdomen	1.5 mm B30f, 1.2 mm increment.		Arterial abdo + CAP in PV phase
Anastamotic leak	CT abdomen and pelvis with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	DEPRECATED SEE BELOW 65 seconds + 1% gastrografin (10 ml gastrografin/L water) timing depending on site e.g. 15-30 mins stomach and duodenum, 60 mins for small bowel, 4 hours for large bowel. PR contrast if distal colonic anastomosis.	CT abdomen and pelvis + i.v. + oral contrast
Oesophageal perforation	CT thorax with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 100 ml 4-6% water soluble contrast slowly over 3-5 minutes before scan	CT thorax/oesophagus with i.v. and oral contrast (100 ml 4-6% water soluble contrast slowly over 3-5 minutes before scan)
Oesophageal surgery (e.g. Ivo Lewis)	CT thorax and abdomen with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 200 ml 4-6% water soluble contrast slowly over 5-10 minutes before scan	CT thorax/oesophagus with i.v. and oral contrast (200 ml 4-6% water soluble contrast slowly over 5-10 minutes before scan)
Gastric surgery (e.g. gastrectomy)	CT abdomen and pelvis with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 300 ml 4-6% water soluble contrast slowly over 15 minutes before scan	CT abdomen and pelvis with i.v. and oral contrast (300 ml water soluble contrast slowly over 15 minutes before scan)
Small bowel with oral contrast	CT abdomen and pelvis with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 500 ml 4-6% water soluble contrast slowly over 30-60 minutes before scan	CT abdomen and pelvis with i.v. and oral contrast (500 ml water soluble contrast slowly over 30-60 minutes before scan)
Leak from roux-en-Y gastrectomy	CT abdomen and pelvis with i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 300 ml 4-6% water soluble contrast slowly over 30-60 minutes before scan then 100 ml slowly over 10 minutes before scan	CT abdomen and pelvis with i.v. and oral contrast (300 ml water soluble contrast slowly over 30-60 minutes before scan then 100 ml slowly over 10 minutes before scan)
Scans requiring rectal contrast	CT abdomen and pelvis with i.v. and rectal contrast	1.5 mm B30f, 1.2 mm increment.	65 seconds + 100 ml 4-6% water soluble contrast rectally before scan	CT abdomen and pelvis with i.v. and rectal contrast (100 ml 4-6% water soluble contrast rectally before scan)
Superior mesenteric artery (SMA) syndrome	CT abdomen & pelvis in arterial phase/angio	1.5 mm B30f, 1.2 mm increment.	CT angio abdomen or abdomen and pelvis (if more clinical questions)	CT angiogram abdomen and pelvis