CT scans take up to 20 minutes for a plain CT and more than 40 minutes for a contrast CT. The extra time for contrast CT is to allow for the dye to reach the desired vessel or part that we wish to visualize on the CT scan. If there is more than one part of the body that is being scanned, it can take even longer.

There are no serious risks associated with the CT scan as the amount of radiation used is low. Still, in a contrast CT scan, it is important to test for sensitivity to the contrast before conducting the test to prevent any allergic reactions due to the contrast. It is, therefore, important to tell the doctor if you have had an allergy to the contrast in a previous CT scan.

There is no specific preparation required for a CT scan. Some tips that might be useful are as follows:

• Remove all your metal ornaments and metal-containing accessories before going into the machine.
• Fast for at least 3–6 hours before a contrast CT scan.
• Follow the instructions provided by the radiologist and CT technician.

CT scans are not prescribed for pregnant women as they can damage the developing fetus, which is very sensitive to radiation. Therefore, do not take a CT scan during pregnancy.

Reports are usually available within 24 hours. In urgent cases, same-day results can be provided.