CT scans (also known as CAT scans or computed axial tomography scans) are advanced x-ray procedures. When a person has a CT scan, they are having many x-rays taken of their body (or part of their body) at nearly the same time. The computer in the CT scanner then combines all of these x-rays to create cross-sectional views and three dimensional images of a patient's internal organs. When a person has a CT scan, they are being exposed to more radiation than when they have a "regular" or conventional x-ray.
CT scans are useful because they help doctors diagnose problems by creating very clear images of internal organs. The detailed images help identify problems inside the body, like tumors or damage to organs. CT scans can also help doctors prepare for surgery by providing a map of the disease or injury that surgeons can follow when operating.