A radionuclide cisternogram is a nuclear scan test. It is used to diagnose problems with the flow of spinal fluid.
CSF flow scan; Cisternogram
How the Test is Performed
A lumbar puncture
(spinal tap) is done first. Small amounts of radioactive material, called a radioisotope, are injected into the fluid within the spine.
You will then be scanned 4 to 6 hours after getting the injection. A special camera takes images that show how the radioactive materials travel with the cerebrospinal fluid through the spine. The images also show if the fluid leaks outside the spine.
You will be scanned again 24 hours after injection. You may need additional scans possibly at 48 and 72 hours after injection.
How to Prepare for the Test
Most of the time you do not need to prepare for this test. Your doctor may give you a medicine to calm your nerves if you are very anxious. You will sign a consent form before the test.
You will wear a hospital gown during the scan so the doctors have access to your spine. You will also need to remove jewelry or metallic objects before the scan.
How the Test will Feel
Numbing medicine will be put on your lower back before the lumbar puncture. However, many people find lumbar puncture somewhat uncomfortable. This is often due to the pressure on the spine when the needle is inserted.
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
The test is performed to detect problems with flow of spinal fluid and spinal fluid leaks.
A normal value indicates normal circulation of CSF through all parts of the brain and spinal cord.
What Abnormal Results Mean
An abnormal result indicates disorders of CSF circulation. These may include:
Risks associated with a lumbar puncture include pain at the injection site, bleeding, and infection. There is also a very rare chance of nerve damage.
The amount of radiation used during the nuclear scan is very small. Almost all of the radiation is gone within a few days. There are no known cases where the radioisotope has caused the patient harm. However, as with any radiation exposure, caution is advised if you are pregnant or breastfeeding.
Very rarely, a person may have an allergic reaction
to the radioisotope used during the scan. This may include a serious anaphylactic reaction
You should lie flat after the lumbar puncture. This can help prevent headache from the lumbar puncture. No other special care is necessary.
Silberstein S, Young W. Headache and Facial Pain. In: Goetz, CG, eds. Textbook of Clinical Neurology. 3rd ed. Philadelphia, PA: Saunders Elsevier; 2007:chap 53.
Jason Levy, MD, Northside Radiology Associates, Atlanta, Georgia. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.