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 witn i.v. and oral contrast	1.5 mm B30f, 1.2 mm increment.	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