Radionuclide cisternogram

• Illustrations
• Alternative names
• Definition
• How the test is performed
• How to prepare for the test
• How the test will feel

• Why the test is performed
• Normal Values
• What abnormal results mean
• What the risks are
• Special considerations
• References

Alternative names    Return to top

Definition    Return to top

A radionuclide cisternogram is a nuclear scan test used to diagnose spinal fluid circulation problems.

How the test is performed    Return to top

First, a lumbar puncture (spinal tap) is performed. Small amounts of radioactive material, called a radioisotope, are then injected into the cerebrospinal fluid at the lower spine. 

You will be scanned 4 - 6 hours later. Medical scanners (such as an MRI or CT ) are used to see how much radiation is given off by the injected materials. The scanners create images that show how the radioactive materials travel with the cerebrospinal fluid through the spine, and if the fluid leaks outside the spine. There will be a series of scans, usually at 4 - 6 hours after injection, again at 24 hours after injection, and possibly again at 48 and 72 hours after injection.

You should lie flat after the lumbar puncture (to help prevent headache from the lumbar puncture). No other special care is usually necessary.

How to prepare for the test    Return to top

No preparation is usually necessary. However, if you are very anxious or agitated, sedation may be necessary. You must sign a consent form. You will wear a hospital gown to make the spine more accessible. Remove jewelry or metallic objects before the scan.

How the test will feel    Return to top

During lumbar puncture, the lower back over the spine is numbed with an anesthetic. However, many people find lumbar puncture somewhat uncomfortable, usually because of the pressure on the spine during insertion of the needle.

The scan is painless, although the table may be cold or hard. No discomfort is produced by the radioisotope or the scanner.

Why the test is performed    Return to top

The test is performed to detect problems with spinal fluid circulation and spinal fluid leaks.

Normal Values    Return to top

A normal value indicates normal circulation of CSF through all parts of the brain and spinal cord.

What abnormal results mean    Return to top

An abnormal study indicates disorders of CSF circulation, including:

• Hydrocephalus
• CSF leak
• Normal pressure hydrocephalus (NPH)
• Whether or not a CSF shunt is open or blocked

What the risks are    Return to top

Risks associated with a lumbar puncture include pain at the injection site and infection.

The amount of radiation used during the nuclear scan is very small, and virtually all of the radiation is gone within a few days. There have been no documented cases of injury or damage caused by the radioisotope used with this scan. However, as with any radiation exposure, caution is advised if you are pregnant or breastfeeding.

In extremely rare cases, a person will develop an allergic reaction to the radioisotope used during the scan. This may include a serious anaphylactic reaction.

Special considerations    Return to top

This procedure requires multiple scans, and the entire test may take 48 - 72 hours. You must be able to lie still during the scan.

References    Return to top

Spelle L, Boulin A, Tainturier C, Visot A, Graveleau P, Pierot L. Neuroimaging features of spontaneous intracranial hypotension.Neuroradiology. 2001 Aug;43(8):622-7.

Spieth ME, Kasner DL. Traumatic thoracic thecal sac laceration, leak, and pleural effusion diagnosed by radionuclide cisternogram. Clin Nucl Med. 2002 Nov;27(11):830-1.

Lund VJ, Savy L, Lloyd G, Howard D. Optimum imaging and diagnosis of cerebrospinal fluid rhinorrhoea. J Laryngol Otol. 2000 Dec;114(12):988-92.