Computed tomography (CT) scanning is a rapid, painless diagnostic examination that combines x-rays and computers. A CT scan allows the radiologist to see the location, nature and extent of many different diseases or abnormalities inside your body.
Multiple low-dose x-rays are taken in sequence by a rotating x-ray tube. All you need to do is lie on a table for less than 5-10 minutes. The table top will move you through a gantry (shaped like a big donut) which houses the x-ray tube and a set of detectors. Images are acquired by detectors that pick-up the x-ray that passes through your body. The computer processes this information to form an image that the radiologist will review and interpret.
Some CT studies require oral contrast and/or intravenous contrast which help the radiologists see things more clearly. You will receive special instructions if your exam requires you to consume an oral contrast agent (barium sulphate) in advance. If your test requires IV contrast, you may be asked to have a blood test to evaluate kidney function. Diabetics may be asked to stop their medication after the exam.