A SPECT scan, or single-photon emission computerized tomography, is a nuclear imaging test that provides 3-dimensional (3-D) pictures of internal organs. Not only does the SPECT scan delineate the organs' structures, it shows the functions of the organs as well. A SPECT scan combines the use of a radioactive tracer and a camera that takes 3-D pictures in order to achieve accurate and detailed results. SPECT scans are commonly used to diagnose or monitor disorders of the heart, brain or bones, but may also be used to provide information about other areas of the body.

Types of SPECT Scans

SPECT scans are helpful in determining how well the targeted organs are functioning, delineate problem areas, and evaluate disease progression.

SPECT Scan of the Brain

A SPECT scan of the brain assists in detecting which parts of the brain are affected by various injuries and disorders, such as: head injuries, seizures, blood vessel clogs, dementia, and certain psychiatric disorders. By highlighting blood flow to a particular region, a SPECT scan of the brain indicates which areas of the brain are most active.

SPECT Scan of the Heart

The radioactive tracer administered during the SPECT scan highlights the flow of blood. Therefore, the scan can evaluate the fluidity of blood flow through the coronary arteries and identify any clogs or blockages. The SPECT scan can also check on the efficiency of the heart's pumping capacity by recording how completely the heart chambers empty.

SPECT Scan of the Bones

Because SPECT scans allow for highlighted bone tissue, they are useful in detecting bone fractures invisible on normal X-rays, and in tracking the healing of such fractures. They are also helpful in assessing the progression of a malignancy that has metastasized to the bones.

SPECT Scans of Other Organs

SPECT scans can also be used to evaluate the lungs and respiratory tract, the liver, the parathyroid gland, certain neurological disorders, like multiple sclerosis and Parkinson's disease, and various vascular conditions.

A SPECT scan produces images that show how the organs work.

Risks of a SPECT Scan

For the vast majority of patients, SPECT scans are safe procedures. The amount of radioactive tracer used in such a scan is kept to a minimum. Nonetheless, women who are pregnant or breast feeding should not be exposed to any radiation since it may affect the fetus or nursing infant. Some patients may experience temporary pain, bleeding or swelling at the site where the tracer is injected. In rare instances, a patient may have an allergic reaction to the radioactive substance itself.

Additional Resources