Ct lumbar scan: definition, process, test results

Definition

What is ct lumbar scan?

A computed tomography (CT) scan, more commonly called a CAT scan, is a type of X-ray that produces cross-sectional images of specific parts of the body. In the case of a CT scan of the lumbar spine, the doctor can see a cross section of the lower back. The scan machine circles the body and sends the images to a computer monitor, where they are reviewed by the technician.

The lumbar spine is a common area where back problems occur. The lumbar spine is the lowest part of the spine, and is composed of 5 vertebrae, including the groin and coccyx. Large blood vessels, nerves, tendons, ligaments and cartilage are also part of the lumbar spine.

When do I need a lumbar CT scan?

CT quickly creates detailed images of the lower back. The test may be useful for looking for:

• birth defects in the child's spine
• lower back injury
• back problems if an MRI can't be used

This test can also be used during or after X-rays of the spine and spinal cord roots (myelography) or X-ray disks (discography).

Precautions & warnings

What should I know before undergoing a CT lumbar scan?

Sometimes your test results may differ from the results of other types of X-ray tests, MRIs, or ultrasound scans, because a CT scan provides a different view. Children who need a CT scan may need special instructions for the test. If the child is too young to survive or if he or she is afraid, the doctor may give a drug (sedative) to help the child relax. If your child is scheduled for a CT scan, talk to your pediatrician about the need for a scan and the risk of radiation exposure to your child. An MRI may provide more information than a CT scan about the spinal disc and spine. When a CT scan of the spine is done with a myelogram, it is called a CT myelogram. MRI of the spine is often performed instead of a CT myelogram.

Process

What should I do before undergoing a CT lumbar scan?

A CT scan of the lumbar spine is a non-invasive test. You can wear loose and comfortable clothing as you will have to lie on a table. You will also be asked to remove jewelry and other metal objects from your body. Tell your doctor if you have metal implants from a previous procedure.

Before a CT scan, tell your doctor if you have any of the following conditions:

• oral contrast (barium) allergy
• diabetes, because fasting might lower blood sugar levels
• pregnant

How is the lumbar CT scan process?

You will be asked to lie down on a narrow table that slides towards the center of the CT scanner. Once you're inside the scanner, the X-ray machine's rays rotate around you. (modern 'spiral' scanners can check without stopping). The computer creates images of separate areas of the backbone, called chunks. This image can be saved, displayed on a monitor, or printed on film. A three-dimensional backbone area model can be created by adding the pieces together. You have to stay still during the inspection. Movement can give a blurry image. You may be asked to hold your breath for short periods of time. After a few rounds of scans, you may be asked to wait while the technician reviews the images to make sure they are clear enough for the doctor to read them correctly. The scan only takes 10-15 minutes.

What should I do after a lumbar CT scan?

After the test, you can change into casual clothes and return to your activities. CT scans generally take a day to process. The doctor will schedule another appointment to discuss the scan results and advise how to proceed depending on the findings. Your doctor may order image scans, additional blood tests, or other diagnostic measurements to help you get an accurate diagnosis and start treatment.

Explanation of the Test Results

What do my test results mean?

Normal result

Results are considered normal if no problems are visible in the lumbar area image.

Abnormal results

Abnormal results may result from:

• birth defects of the spine
• bone problems
• cracked
• lumbar disk hernia
• lumbar spinal stenosis
• spondylolisthesis