﻿ Lumbosacral spine CT

Lumbosacral spine CT


A lumbosacral spine CT is a computed tomography scan of the lower spine and surrounding tissues.

Alternative Names

Spinal CT; CT - lumbosacral spine

How the Test is Performed

You will be asked to lie on a narrow table that slides into the center of the CT scanner. You will need to lie on your back for this test.




In some cases, an iodine-based dye, called contrast, may be injected into your vein before images are taken. Contrast can highlight specific areas inside the body, which creates a clearer image.

In other cases, a CT of the lumbosacral spine may be done after injecting contrast dye into the spinal canal during a lumbar puncture to further check for pressure on the nerves.

The scan will usually last a few minutes.

How to Prepare for the Test

You should remove all jewelry or other metal objects before the test, as they may cause inaccurate images.

How the Test Will Feel

The x-rays are painless. Some people may have discomfort from lying on the hard table.


Why the Test is Performed

CT rapidly creates detailed pictures of the body. A CT of the lumbosacral spine is an excellent tool for evaluating fractures and degenerative changes of the spine, such as those due to arthritis.

What Abnormal Results Mean

CT of the lumbosacral spine may reveal the following conditions or diseases:


The most common type of contrast given into a vein contains iodine. If a person with an iodine allergy is given this type of contrast, hives, itching, nausea, breathing difficulty, or other symptoms may occur.


CT scans and other x-rays are strictly monitored and controlled to make sure they use the least amount of radiation. CT scans do create low levels of ionizing radiation, which have the potential to cause cancer and other defects. However, the risk associated with any individual scan is small. The risk increases as numerous additional studies are performed.


Pregnant or breastfeeding women should consult their health care provider about the risk of CT scans to the baby.


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Grainger RG, Thomsen HS, Morcos SK, et al. Intravascular contrast media for radiology, CT and MRI. In: Grainger RC, Allison D, Adam A, Dixon AK, eds. Diagnostic Radiology: A Textbook of Medical Imaging. 4th ed. New York, NY: Churchill Livingstone; 2001:chap 2.

Mettler FA. Skeletal system. In: Mettler FA Jr, ed. Essentials of Radiology. 2nd ed. Philadelphia, Pa: Saunders Elsevier; 2005:chap 8.

Review Date: 8/11/2008