What is CT ?
Computed Tomography scan (CT scan, previously known as a CAT scan) is a scan that uses x-rays and a computer to create images of the body in great detail. In hospitals it is used to image all sorts of medical and surgical problems, but for sports medicine, it is mostly used to look at bones that have been affected by arthritis, injury or surgery. It cannot distinguish soft tissues in as much detail as MRI or ultrasound but it is better for looking at certain conditions of bone (including fractures), and for finding loose material within joints.
Can everyone have a CT ?
Yes, there are no conditions that would stop anyone from having a scan, in fact CT is often used on patients who cannot have an MRI for any reason (see MRI section). A CT scan uses x-rays which are known to cause harm to the body in high doses. The x-ray doses encountered in most sports medicine CT scans are usually very low compared to other types of CT scan however, and well within legally set limits for exposure. The Radiologist (the doctor responsible for performing and reporting the scan) is specially qualified to minimise the x ray dose to the patient when performing the scan for maximum safety.
How is a CT performed ?
The scanner comprises of a mobile bench which moves the patient through a circular scanner. The scan is painless and takes only a few seconds. The patient may have to lie in particular position for the scan, and is required to stay still for the duration of the scan. In some types of scan, a dye is used to gain more information, but this is not often the case with sports imaging scans. Once the scan is over, the patient is free to go home and resume normal activities. The pictures are then looked at by a specially qualified doctor (Radiologist) and a report is made for the treating doctor to act upon.
CT scan of a shoulder joint (compare with the ultrasound and MRI pictures in the relevant pages). Bone is seen as bright white and is seen in great internal detail. Although muscles and tendons can be seen, this is not the best scan for these. CT is best for looking at bone fractures, and a fracture can be seen on this picture (black asterisk).