A CT scan (computed tomography) combines X-rays with computer technology to produce a more detailed, cross-sectional image of your body. You will be asked to lie on a narrow table that slides into the center of the CT scanner. Once you are inside the scanner, the machine’s x-ray beam rotates around you. (Modern “spiral” scanners can perform the exam without stopping.) A computer creates separate images of the body area, called slices. These images can be stored, viewed on a monitor, or printed on film. Stacking the slices together can create three-dimensional models of the body area. You must be still during the exam, because movement causes blurred images. You may be told to hold your breath for short periods of time.
It may be ordered if your doctor wants to evaluate spinal degenerative conditions such as spinal stenosis or disc herniation. Occasionally, there may be reason to suspects a tumor or a fracture that doesn’t appear on X-rays (such as in your collarbone or pelvis) or if you’ve had severe trauma to the chest, abdomen, pelvis or spinal cord. The process is painless. Most CT scans are performed without contrast. Contrast may be injected by a radiologist into the spine prior the scan in order to better enhance the spinal nerves on the images. This is called a CT myelogram. Tell your doctor if you are pregnant before undergoing a CT scan.