Single photon emission computed tomography

A SPECT scan is done to:

• Check to see how well treatments are working.
• Examine bones for signs of cancer and sometimes for fractures or degenerative bone diseases such as osteoporosis.
• Evaluate brain conditions. These may include Alzheimer's disease and other types of dementia, Parkinson's, transient ischemic attack (TIA), and stroke.
• Help diagnose some psychological conditions, such as schizophrenia.
• Help determine brain death.
• Find out what's causing seizures, including for epilepsy.
• Find poor blood flow to the heart, which may mean coronary artery disease or other heart conditions.
• Assess heart attack risk or find damaged heart tissue after a heart attack.
• Diagnose gallbladder disease.
• Evaluate the extent of some cancers, especially lymphomas and lung cancer.
• Help a doctor choose the best treatment for cancer. Or it can find out how well cancer treatment is working.
• Check the liver, kidney, and spleen for cancers.
• Find tumors in the endocrine system.
• Find areas of inflammation or infection.

A SPECT scan is done in a hospital nuclear medicine department. You will lie on a table that is hooked to a large scanner, cameras, and a computer.

The radioactive tracer is usually given in a vein (I.V.). You may need to wait as long as an hour for the tracer to move through your body. During this time, you may need to avoid moving and talking.

The SPECT scanner is a large machine that scans your body. It has two cameras that rotate slowly around your body. They will be very close to your body but should not touch you. The scanned pictures are sent to a computer screen so your doctor can see them. Many scans are done to make a series of pictures.

It's very important to lie still while each scan is being done. At some medical centers, a CT scan will be done at the same time.

For a SPECT scan of the brain, you will lie on a bed. You may be asked to read, name letters, or tell a story, depending on whether speech, reasoning, or memory is being tested. During the scan, you may be given earplugs and a blindfold (if you don't need to read during the test) to wear for your comfort.

If you are having a SPECT scan of your heart, electrodes for an electrocardiogram (EKG, ECG) will be put on your body. During the test, you will be alone in the scanner room. The technologist will watch you through a window. You will be able to talk to each other at all times through a two-way intercom.

• Tell your doctor if you have diabetes. If you take medicine to control diabetes, you may need to take less than your normal dose. Talk with your doctor about how much medicine you should take.
• Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may increase the risk of problems during your test. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.
• If you are breastfeeding, you may want to pump enough breast milk before the test to get through 1 to 2 days of feeding. The radioactive tracer used in this test can get into your breast milk and is not good for the baby.
• Tell your doctor if you get nervous in tight spaces. You may get a medicine to help you relax. If you think you'll get this medicine, be sure you have someone to take you home.
• You may not be able to eat or drink for at least 6 hours before some SPECT scans. Ask your doctor when or if you need to fast before the test.
• Your doctor will also let you know if you should avoid smoking or avoid drinking caffeine or alcohol for 24 hours before this test.

The radiologist may discuss preliminary results of the SPECT scan with you right after the test. Complete results are usually available in 1 to 2 days.

Heart

Brain (such as epilepsy, dementia, stroke)

Bone

Other