The CT scanner is a large machine with a hole in the center. Before the scan begins, you’ll need to remove jewelry from the area being scanned. (The metal in the jewelry can change the image of the scan.)
You will be asked to lie on a table that slides into the center of the machine. In some cases, you may need to lie on your stomach. Usually, you will lie on your back. The scan itself is painless.
Once you’re inside the scanner, the machine's X-ray beam rotates around you. You’ll need to be still during the exam. Any movement can blur the images. You may be asked to hold your breath for short periods of time. You will hear clicking and whirring noises.
Generally, scans take only a few minutes. The newest machines can scan your entire body, head to toe, in less than 30 seconds.
Some CT exams need to use a special dye called contrast. Contrast helps create a clearer image. You may need to swallow the contrast. Or it may be put into your body through an intravenous line (IV).
If you get contrast through an IV, you may get a slight metallic taste in your mouth. Some people also feel a warm flushing feeling. This is normal, and it usually go away in a few seconds.
If have a scan that needs to use contrast, you may have to stop eating and drinking four to six hours before the test.