A Single-Photon Emission Computerized Tomography (SPECT) scan is a type of nuclear medicine imaging test that assists your doctor in analyzing the function of certain internal organs. Nuclear Medicine is an imaging technology that involves the use of small amounts of radioactive materials (or tracers) to help diagnose and treat a variety of diseases.

Nuclear medicine determines the cause of the medical problem based on the function of the organ, tissue or bone. This test uses a small amount of radioactive material to emit photon energy. This energy is detected by a gamma camera which then captures and creates computerized images.

Your doctor may determine that a SPECT scan is appropriate in order to help diagnose or monitor bone disorders, brain disorders and heart problems.

While imaging tests like x-rays can show what the structures inside your body look like, a SPECT scan produces images that show how your organs work. As an example, a SPECT scan can show what areas of your brain are more active or less active.

SPECT can be helpful in determining which parts of the brain are being affected by:

• Dementia
• Clogged blood vessels
• Seizures
• Epilepsy
• Head injuries

Because the radioactive tracer highlights areas of blood flow, SPECT can check for:

• Clogged coronary arteries. If the arteries that feed the heart muscle become narrowed or clogged, the portions of the heart muscle served by these arteries can become damaged or even die.
• Reduced pumping efficiency. SPECT can show how completely your heart chambers empty during contractions.
• Areas of bone healing or cancer progression usually light up on SPECT scans, so this type of test is being used more frequently to help diagnose hidden bone fractures. SPECT scans can also diagnose and track the progression of cancer that has spread to the bones.

You will lie on an examination table. If necessary, a technologist will insert an intravenous (IV) catheter into a vein in your hand or arm. 

Depending on your type of nuclear medicine exam, the radiotracer is injected intravenously, swallowed or inhaled as a gas. 

It can take anywhere from several seconds to several days for the radiotracer to travel through your body and accumulate in the area under study. As a result, imaging may be done immediately, a few hours later, or even several days after you receive the radioactive material. 

When it is time for the imaging to begin, the camera or scanner will take a series of images. The camera may rotate around you or it may stay in one position and you may be asked to change positions in between images. While the camera is taking pictures, you will need to remain still for brief periods of time. In some cases, the camera may move very close to your body. This is necessary to obtain the best quality images. If you are claustrophobic, you should inform the technologist before your exam begins. 

The radiopharmaceutical you receive for the study is eliminated from your body through the urine. For that reason, you should drink plenty of fluids and urinate frequently after completion of the test. How much fluid will depend on each individual, but you should be well hydrated. 

For an adult this could be three to four glasses of water.  

Your urine will not change color. Your urine will contain the radioactive material, so it is recommended that you thoroughly wash your hands after going to the bathroom.

Typically, a SPECT scan takes approximately 30 minutes to complete.