For plain CT scans no preparation is required. The scan is quick and may take a few minutes on the scan table. Getting prepared for the scan may take 15 to 20 minutes. If intravenous contrast is needed to be given the scan will be labelled as with contrast by your referring doctor. Blood urea and serum creatinine tests will be required for a contrast study. Please get this test done at a nearby pathological laboratory and bring the results with you when you come for scan. If these tests show that the kidney function is suboptimal then your referring doctor may decide to give premedication prior to the scan or decide to avoid the scan altogether.
Be sure to mention if you are allergic to the contrast taken during a prior test or to any other food or medicines as people with such allergies may also develop an allergy to this contrast. In such cases premedication with antiallergy medicines can be given prior to the scan or the scan can be avoided. These group of patients are usually scanned with a critical care expert doctor standing by in the scan room for expertly managing any allergic reaction.
Contrast scans take a little longer. So come with two hours of time in hand. Drink plenty of water the day before and on the day of the scan to keep yourself well hydrated so that the injected contrast will be flushed out of the system by the kidneys. This typically happens within 24 hours by normal kidneys. An intravenous cannula is placed in a forearm vein prior to the scan. During the scan the contrast is injected via this cannula. You may feel a sensation of flushing or odd taste in the mouth. Otherwise, this does not give any discomfort.
After the scan you may go back home and continue your regular day. Avoid heavy physical activity after the scan. Remain well hydrated. Report any rashes or other symptoms to your treating doctor without delay.