What Is Nuclear Medicine?

ImageNuclear medicine is a branch of medical imaging that uses small amounts of radioactive material, called a radiotracer, to diagnose or treat a variety of diseases, including many types of cancers, heart disease and certain other abnormalities within the body. Procedures are noninvasive and, with the exception of intravenous injections, usually painless medical tests.

Depending on the type of nuclear medicine exam you are undergoing, the radiotracer is either injected into a vein, swallowed or inhaled as a gas and eventually accumulates in the organ or area of your body being examined, where it gives off energy in the form of gamma rays.

This energy is detected by a device called a gamma camera, a positron emission tomography (PET) scanner and/or a probe. These devices work together with a computer to measure the amount of radiotracer absorbed by your body and to produce special pictures offering details on both the structure and function of organs and tissues.

In some centers, nuclear medicine images can be superimposed with computed tomography (CT) or magnetic resonance imaging (MRI) to produce special views, a practice known as image fusion or co-registration. These views allow the information from two different studies to be correlated and interpreted on one image, leading to more precise information and accurate diagnoses.

In addition, manufacturers are now making single-photon emission computed tomography/computed tomography (SPECT/CT) and positron emission tomography/computed tomography (PET/CT) units that are able to perform both imaging studies at the same time.

Nuclear medicine also offers therapeutic procedures such as radioactive iodine (I-131) therapy, which uses radioactive material to treat cancer and other medical conditions affecting the thyroid gland.

Watch a video of the Symbia SPECT/CT technology in action.

ImageWhat Are Some Common Uses of the Procedure?
Physicians use nuclear medicine procedures to visualize the structure and function of an organ, tissue, bone or system of the body.

Nuclear medicine imaging scans are performed to:

  • Analyze kidney function.
  • Visualize heart blood flow and function (such as a myocardial perfusion scan).
  • Scan lungs for respiratory and blood flow problems.
  • Identify inflammation in the gallbladder.
  • Evaluate bones for fractures, infection, arthritis and tumors.
  • Determine the presence or spread of cancer in various parts of the body.
  • Identify bleeding into the bowel.
  • Locate the presence of infection.
  • Measure thyroid function to detect an overactive or underactive thyroid.
  • Investigate abnormalities in the brain, such as seizures, memory loss and abnormalities in blood flow.
  • Localize the lymph nodes before surgery in patients with breast cancer or melanoma.

In children, nuclear medicine is also used to:

  • Investigate abnormalities in the esophagus, kidneys and intestines.
  • Evaluate the openness of tear ducts and shunts in the brain and heart.

Nuclear medicine therapies include:

  • Radioactive iodine (I-131) therapy used to treat hyperthyroidism (overactive thyroid gland—for example, Graves’ disease) and thyroid cancer.
  • Radioactive antibodies used to treat certain forms of lymphoma (cancer of the lymphatic system).
  • Radioactive phosphorus (P-32) used to treat certain blood disorders.
  • Radioactive materials used to treat painful tumor metastases to the bones.
  • I-131 MIBG (radioactive iodine laced with metaiodobenzylguanidine) used to treat adrenal gland tumors in adults and nerve tissue tumors in children.

What to Expect
A nuclear medicine scan is completely painless and has no side effects.

You will be given a radioactive material, or isotope. It may be injected, swallowed or inhaled. Your scan may then be done right away, or you may need to wait a few hours or days to allow the isotope to concentrate in the part of the body being studied. You will lie on a narrow imaging table. A large camera is placed close to your body. To ensure the best images, it is important to remain as still as you can while the camera takes the pictures. The table or camera may be adjusted to take more pictures. Your scan may take a few hours. Bring something you can do if you need to wait.

Afterward, drink plenty of water to help clear the isotope from your body. The isotope leaves your body within hours.

ImageAfter the area being studied processes the radioactive isotope and the scanner records the information, a trained radiologist interprets the images. Results are usually reported to your referring physician within 48 hours.

What Are the Benefits and Risks?
The information provided by nuclear medicine examinations is unique and often unattainable using other imaging procedures. For many diseases, nuclear medicine scans yield the most useful information needed to make a diagnosis or to determine appropriate treatment, if any. The benefit of an accurate diagnosis far outweighs the risk. Your physician will discuss with you any questions and concerns you have with any of these procedures.

Gwinnett Medical Center Imaging has three convenient Atlanta-area locations in Lawrenceville, Duluth or Hamilton Mill. If you would like to schedule an appointment, please call 678-312-3444.