A narrow x-ray beam is quickly rotated around a patient's body during a computerized x-ray imaging method known as a CT scan. This produces signals that are analysed by the machine's computer to create cross-sectional images, or "slices," of the patient's body. These sections, which are known as tomographic pictures, can provide a referring physician with more diagnostic clinical data than traditional x-rays. When multiple sequential slices are gathered by the machine's computer, they can be digitally combined to create a three-dimensional (3D) image of the patient, making it easier to identify the patient's basic structures.  A CT scan is particularly helpful when imaging complex bone fractures, severely eroded joints, or bone tumours since it typically produces more detail than would be available with a standard x-ray