Single Photon Emission Computed Tomography Scan Of The Brain

What is it?

A brain single photon emission computed tomography (SPECT) scan is a test that shows how and where blood is flowing in your brain. It gives caregivers a picture of how your brain works. This test is a type of nuclear (NEW-klee-er) medicine scan. It is also called neurologic (ner-ih-LOJ-ik) imaging.

Why do I need a brain SPECT?

A brain SPECT may be done to see if an abnormal process is happening in your brain. This test may also be done to find or monitor any of the following medical conditions:

  • Alzheimer's disease, or other types of dementia (duh-MEN-shuh).

  • Cancer or stroke.

  • Chronic fatigue syndrome (extreme tiredness).

  • Head trauma (injury).

  • Memory loss, or migraine headaches.

  • Neurological diseases, such as encephalitis (n-SEF-uh-LI-tis), epilepsy, Huntington's disease, hydrocephalus (hi-dro-SEF-uh-lus), and Parkinson's disease.

  • Problems with blood flow in the brain, or brain death.

  • Schizophrenia (skiz-oh-FRE-nee-ah).

  • Toxic encephalopathy (n-sef-uh-LAW-puh-thee).

Who should not have this test?

Tell your caregiver before the test if you might be or are pregnant. Caregivers may suggest waiting to have the test until after your baby is born. Tell caregivers if you are breast feeding. They may suggest waiting to have the test until after you have finished breast feeding your baby. This is suggested so that your baby will not receive any of the radioactive tracer.

What should I do to get ready for the brain SPECT?

You do not have to do anything to prepare for the scan. You may eat, drink fluids and take any medicines that you take regularly.

Informed consent

is a legal document that explains the tests, treatments, or procedures that you may need. Informed consent means you understand what will be done and can make decisions about what you want. You give your permission when you sign the consent form. You can have someone sign this form for you if you are not able to sign it. You have the right to understand your medical care in words you know. Before you sign the consent form, understand the risks and benefits of what will be done. Make sure all your questions are answered.

How is a brain SPECT performed?

Your caregiver will tell you what time to come to the Nuclear Medicine department where the scan is performed.

  • Caregivers will ask you to go to the bathroom before the scan begins. You should do this because you will need to lie down for about two hours. You will be asked to lie down and rest in a dimly light room for about 15 to 60 minutes. A caregiver will put a substance called a radioactive tracer into a vein, usually in your hand or arm. You may need to breathe in the radioactive tracer instead of receiving it as a shot. You will rest for about 45 minutes in the dimly lit room to allow the tracer to flow through your brain.

  • Caregivers may have you place your head in a special holder, and wrap it with an elastic bandage. This may be done to hold your head still. The tracer decays (breaks down) to a single piece called a photon. The scan is taken with a gamma camera that rotates around to track the photons. A computer makes pictures of different areas of your brain from the scan. It usually takes about 30 to 90 minutes to complete the scan.

What will I feel during the scan?

You may feel discomfort when the tracer medicine is put in your vein. The scan itself is painless, but you may be uncomfortable lying still during the scan. Caregivers may offer you medicine, called a sedative, to help you lie still. Because sedatives can slow brain activity, you cannot receive this medicine until after you are given the tracer medicine.

What should I do after the scan?

You may continue activities, eat, drink, and take your usual medicines as you did before the test. Drink plenty of fluids, such as water and juices to help flush the tracer out of your body. The tracer leaves your body quickly through your urine. Your caregiver may ask you to flush the toilet three times after going to the bathroom. This makes sure that the small amount of tracer leaving your body does not stay in the toilet bowl.

What are normal and abnormal results?

All the cells in a normal brain SPECT will look the same. An abnormal scan can have "hot" or "cold" spots. A hot spot is an area that looks black because brain cell growth is more active. Because of this growth, more of the tracer is absorbed. A cold spot is an area that looks lighter or white because the brain cells are less active. These areas absorb less of the tracer.


You may feel dizzy and unsteady when getting up from a sitting or lying position after the scan. You may hear ringing in your ears, or feel sick to your stomach. You may have burning, prickling or unusual feelings on your skin. The place where the medicine was given could bleed, become red, swollen, painful, or infected. Rarely, a person may develop a rash, swelling, or have an allergic reaction to the tracer medicine. If you do not have a brain SPECT, caregivers may not be able to decide what would be the best care for your health problems. Your problem could get worse or you could die. Call your caregiver if you are worried or have questions about your medicine or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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