Brain Scans

A brain scan takes about 45 minutes.

Before the scan:

• You’ll be checked for iodine allergy (if iodine will be mixed with the isotope).
• You may receive a blocking agent that will help control how the isotope is absorbed.

During the Scan:

• You’ll receive the isotope by injection.
• A technologist will help position you in front of a camera.
• You’ll stay very still (for about 3 minutes) while the scan records blood flow through the brain.

Another scan (lasting about ½ hour) will be done ½ hour to 2 hours later to check brain tissue.

After the Scan:

• Drink plenty of fluids to help clear your body of the isotope.

Nuclear brain scans can reveal problems such as tumors, aneurysms (ballooning of an artery) and hydrocephalus (water on the brain). Thyroid uptake and scan give important information about the thyroid (a gland in the neck). These procedures are generally done over a 2-day period.

Before these procedures:

• You may be asked to avoid food and water (starting the night before day 1).
• You may also need to avoid certain foods or medications in the weeks before the test.

On day 1: You’ll receive the isotope, usually by mouth (liquid or capsule). You may be asked to avoid eating or drinking for 1-2 hours afterwards.

On day 2: About 24 hours after receiving the isotope, you’ll sit or lie down for:

• The uptake – a probe is placed in front of your neck for 1 minute and then over your thigh for 1 minute. This measures your thyroid’s ability to absorb the isotope. This takes about 5 minutes.
• The scan – after receiving an injection into a vein in your arm, a gamma camera will take pictures to show your thyroid’s condition and ability to function. This takes about 45 minutes.

NOTE: You may need just one of these procedures done. You may also need one or both done on day 1, about 4-6 hours after receiving the isotope.

If you need a scan only (no uptake), you’ll usually receive the isotope by injection.