Preparation for a CT scan
For most scans, you have a drink or an injection of contrast medium, or both. This is a dye that shows up body tissues more clearly on the scan. You have the injection through a small thin tube (cannula) into your arm. The cannula stays in place until after your scan. This is in case you have any problems such as an allergic reaction after having the injection. CT scans of the tummy (abdomen) If you are having a CT scan of your abdomen, you might need to: drink a liquid contrast medium some time before the scan drink more of the liquid contrast or water in the x-ray department stop eating or drinking after midnight the night before the scan (this is for a CT scan of the inside of the large bowel, called CT colonography) You usually have the contrast medium by injection and also as a drink. This helps to show up the gut ( digestive system ) more clearly in the scan. CT scans of the head For some brain scans, you might have an injection of the contrast medium dye b...