CT imaging, also known as "CAT scanning" (Computed Axial Tomography), combines the use of a digital computer with a rotating x-ray device. This combination creates detailed cross sectional images or "slices" of the different organs and body parts such as the lungs, liver, kidneys, pancreas, pelvis, extremities, brain, spine and blood vessels. For most patients, CT can be performed on an outpatient basis.

Among the various imaging techniques such as MRI and X-ray, CT has the unique ability to image a soft tissue, bone and blood vessels. CT images of the head allow physicians to see soft-tissue structures like the brain's ventricles or gray and white matter. Physicians can selectively choose the digital CT images on the computer monitor to look at the soft tissue, then the bone and then the blood vessels, as needed.