Cisternogram Scan

What is a cisternogram scan?

A cisternogram scan is a diagnostic procedure that evaluates how cerebrospinal fluid (CSF) flows around your brain and spinal cord. This protective fluid:

• Delivers nutrients to your brain and spine.
• Helps your central nervous system (CNS) work.
• Removes toxins from tissues in your CNS.
• Acts like a cushion to protect your brain from concussion.

Cisternography is a type of nuclear medicine imaging. That’s why providers also call this scan a radionuclide cisternogram. During this test, you receive an injection of radioactive material in your spine. Radioactive substances allow certain body parts or functions to show up better on imaging scans. Your healthcare provider can see how the CSF flows around your brain and spinal cord.

When is a cisternogram needed?

Your healthcare provider may order a cisternogram if they think you have a CSF leak (too little pressure on your brain or spine) or a buildup of CSF (too much pressure on your brain or spine). Symptoms of either can include:

• Balance problems.
• Dizziness.
• Headaches.
• Hearing loss.
• Nausea and vomiting.
• Neck pain.
• Sensitivity to light or sound.
• Trouble thinking clearly or concentrating.

How do I prepare for a cisternogram scan?

Most people don’t need to do anything to prepare for a cisternogram. In some cases, your healthcare provider may give you special instructions about eating or drinking before the procedure. You should plan to have someone drive you home after your test.

It’s important to tell your healthcare provider about:

• Allergies to local anesthetic (medicine to numb certain areas of your body) or anesthesia.
• Any possibility that you might be pregnant.
• Medications you take, including vitamins and supplements. Some medications increase your risk of bleeding, so you might need to stop taking these before the procedure.

What happens during a cisternogram?

The first step of a cisternogram is a spinal tap (lumbar puncture):

• You receive an injection of a local anesthetic to numb your spine. Some people may also need a sedative to stay calm or, in rare cases, general anesthesia.
• You lie face down on a table, or on your side with your knees pulled up toward your chest.
• Your healthcare provider inserts a thin, hollow needle into your spine. Fluoroscopy (real-time X-ray) helps guide the needle between your vertebrae (spinal bones) and into the space around your spinal cord.
• The needle injects a radioactive substance into your cerebrospinal fluid (CSF).
• Your healthcare provider removes the needle.

After the lumbar puncture, you lay very still for about an hour while the radioactive substance moves through your CSF. Between one and six hours after the lumbar puncture, your healthcare provider performs imaging scans of your spine. They use a special camera that detects radioactive material. A CT scan or MRI creates the images.

You can go home after your imaging scan but will need to return 24 hours later for another imaging scan. It can take a full day for the radioactive substance to reach all the cavities in your brain. Some people also get scans 48 and 72 hours after the procedure. You don’t need additional lumbar punctures before each imaging scan.

Does a cisternogram scan hurt?

You might feel some stinging or discomfort during the injection of local anesthetic. When the needle goes into your spine, you may notice some pressure but shouldn’t feel any pain. The imaging scans are painless.

Does a cisternogram have side effects?

The most common side effects after a cisternogram are pain where you received your injection and headache. Spinal headaches can occur after a lumbar puncture because CSF fluid may leak out of the injection site. This temporary leak causes the pressure in your brain to drop, which can lead to an intense headache. It should go away on its own within a few hours or days.

Are there any risks with a cisternogram?

Complications after a cisternogram are rare, but potential risks include:

• Allergic reactions to the radioactive substance or anesthesia.
• Brainstem herniation (pressure inside the skull moves brain tissue).
• Hemorrhage (bleeding) in the brain or spine.
• Infection.
• Nerve damage.

There is some radiation exposure during a cisternogram, but it’s a very low dose.

When will I know the results of the cisternogram scan?

You may need to wait several days or a week after your last scan for results. Ask your healthcare provider when you can expect them.

What do cisternogram results mean?

If your cisternogram is normal, it means CSF is flowing around your brain and spinal cord normally. There are no leaks or blockages.

Abnormal results could indicate:

• CSF leak, which is often the result of a traumatic brain injury, skull fractures or damage to the dura mater (outermost covering of the spinal cord). CSF leaks can also occur after certain surgeries or procedures.
• CSF shunt problems, which can occur if a shunt (tiny drainage tube) in the brain stops working properly. Shunts are the most common treatment for hydrocephalus.
• Hydrocephalus, which is pressure on the brain caused by a buildup of CSF.
• Normal-pressure hydrocephalus (NPH), which is a buildup of CSF that doesn’t increase pressure on the brain.
• Pseudotumor cerebri, or “false brain tumor,” which is pressure on the brain with no known cause. It’s also called idiopathic intracranial hypertension.

A note from Cleveland Clinic

A cisternogram scan is a procedure to test how the cerebrospinal fluid (CSF) flows around your brain and spinal cord. Your healthcare provider might order this test if they suspect you have a CSF leak or a buildup of CSF. A cisternogram requires a lumbar puncture and a series of imaging exams.