Description | Indications | Mechanism | Limitations | Risks

CT Scans - Spinal diagnostic test

Description:

Computer assisted tomography or CT scan, involves a series of x-rays that are interpreted by a computer which generates images that appear as slices through the body. Both bones and soft tissue can be visualized, and the images can be computer generated into three dimensional views of the anatomical structures.

Indications:

CT scans produce very detailed images of bony structures visualized in each slice generated by the computer. Many conditions, such as fractures, cancer, infections, nerve root irritation related to bony compression, can be visualized on a CT scan.

Mechanism:

For approximately 30-60 minutes, the patient receiving a CT scan lies on a table that slides into an x-ray tube which rotates in a circular fashion. The patient is asked to lie very still while the pictures are actually taken.

Limitations:

The CT scan does not visualize soft tissue, such as ligaments or muscles, as well as an MRI scan, which is a better test to demonstrate spinal problems such as disc herniation. The CT scan can be more effective when a dye is utilized in the spinal sac, so that nerves can be more clearly visualized. This procedure is called a myelogram, and can be effective in demonstrating disc disease.

Risks:

The CT scan utilizes radiation, much as does a plain x-ray. In large quantities, radiation can increase cancer risk, though the vast majority of patients will never receive enough radiation for this to become problematic. Adults of child rearing age, children and pregnant women, should be protected from radiation through the use of a lead apron that protects the genital organs.