This cross-sectional imaging technology allows the radiologist to look at different levels, or slices, of the middle portion of the back using a rotating X-ray beam. The radiologist views each slice to check for injuries and bony abnormalities.

The exam may include injecting an iodine substance in the vein. Diabetic patients and those with allergies must inform the radiology staff and may need clearance from their doctor before the exam. Blood tests may also be required prior to the administration of contrast materials. Patients whose exam includes an injection will be instructed not to eat or drink anything four hours before the test. During the injection, the patient may experience a warm sensation throughout the body and a metal taste in the mouth. This is normal.

Patients lie on their backs with the arms positioned above the head for the procedure. A portion of the body is covered by the scanner, and the scanner is open at the back and the front, allowing the patient to see out. The technologist is always able to see and hear the patient during the 30-minute procedure.