The patient moves through the gantry (circular donut shaped part of the scanner) on a movable table. At the same time, a rotating x-ray machine inside the gantry moves around the body. As the patient moves through the gantry, the detectors constantly collect data as the radiation passes through your body, and with the aid of a complex computer, a two -dimensional image is created.

 A completed scan may have as little as 20 images, such as CT of the brain, while others have several hundred images, as is the case with a CT of the abdomen. Each image represents a section of the body, which can be thick (10mm) or thin (0.5mm) depending upon the body part being examined. The CT examination fast and painless.