Cervical, Thoracic, Lumbosacral Low Dose Intrathecal Contrast Enhanced CAT Scan

Peer Reviewed

What is a low dose intrathecal contrast enhanced CAT SCAN?

This is a study similar to a myelogram that utilizes contrast or x-ray dye to better visualize the spinal canal and nerve roots in the spine. A very low dose of intrathecal contrast (dye) is injected into a spinal sac (where the spinal fluid is located) and follow-up CAT SCAN pictures are taken. This is strictly a diagnostic test. Regardless of what area is to be studied, the contrast is injected in the low back and then the patient is moved into a position that enables the flow of contrast to reach the area of interest.
A medical equipment CAT scan machineThe patient is given a CAT SCAN and pictures are taken of the area of interest. Photo Source: 123RF.com.

What happens during the procedure?

An IV will be started so that relaxation medication can be given. Patients are placed on the x-ray table on their sides and positioned in such a way that the physician can best visualize the low back using x-ray guidance. The skin is scrubbed using 2 types of sterile scrub (soap). Next, the physician numbs a small area of skin with numbing medicine. This medicine stings for several seconds. After the numbing medicine has had time to take effect, the physician uses x-ray guidance to direct a small needle into the intrathecal sac. A small amount of contract (dye) is injected. The patient is then given a CAT SCAN and pictures are taken of the area of interest. This CAT SCAN takes approximately 46 - 60 minutes.

What happens after the procedure?

After the CAT SCAN, patients are taken back to the recovery area where they are monitored for 4 hours. Patients are encouraged to drink plenty of caffeinated beverages and be given instructions for strict bed rest for the next 24 hours. Patients are only allowed to get up to go to the bathroom. This is to prevent spinal headaches. It is important that patients have a ride home and that the car in which they will be riding has reclining seats so they can lie down for the trip home.

General Pre/Post Instructions

Patients can eat a light meal within a few hours before the procedure. Patient who are insulin dependent diabetics must not change their normal eating patterns prior to the procedure. Patients may take their routine medications (i.e. high blood pressure and diabetic medications).

Commentary by: Brian R. Subach, MD

In these articles, Dr. Dreyfuss carefully explains three diagnostic techniques available to spine surgeons. The first test is myelography with CT scanning. Not only does the method give excellent imaging of both the bones and the exiting nerves, but it is less likely to show the artifact associated with hardware placement when compared to a normal MRI. The second technique is considered a provocative test in which dye is injected slowly into a disc to learn about possible degeneration in the disc itself and the ability of the disc to cause or contribute to pain. The third technique is designed to alleviate pain originating in the region of the facet joints and therefore identify them as problem sites. Although the test may only have a temporary effect, the information gained often guides patient care.

These patient oriented articles illustrate how anatomic imaging, provocative testing, and pain alleviation techniques all contribute to a surgeon's ability to understand the spine and diagnose its disorders.

Updated on: 04/02/19
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Neurology Basics: Neurological Exams
Brian R. Subach, MD
Spinal Neurosurgeon
Subach Spinal Solutions, PLC
Arlington, VA
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