Nuclear Medicine

Nuclear medicine is a safe and effective method of studying how your organs and other body parts function. The exam allows your doctor to evaluate organs, and areas within organs, that aren’t evident on conventional x-rays. For example, instead of just viewing a detailed image of your kidney, your doctor can use nuclear medicine to see how your kidney is functioning.

During the exam, a trace amount of radioactive material, called radiopharmaceutical, is introduced into your system. This radioactive material travels to the area to be studied and emits a form of radiation called gamma rays. These emissions are detected by a machine called a gamma camera. A special computer converts the readings into images, and a nuclear medicine physician analyzes the findings.

You might think of a nuclear medicine exam as an inside out x-ray. The medicine records the radiation emitting from your body rather than radiation that is directed through your body.

Why is Nuclear Medicine Used?

There are more than 100 different nuclear medicine examination techniques that allow doctors to evaluate organ function, making it an invaluable tool in early detection and diagnosis of many diseases.

Various types of nuclear medicine exams are given for different reasons.

  • Bone scans can detect bone tumors, breaks, infections, and arthritis.
  • Brain scans are done for people who have had a stroke or who have seizures or related conditions. 
  • Cardiac scans can detect heart attacks and evaluate damage, measure the strength and efficiency of blood flow, and aid in stress tests.
  • Gallbladder scans help detect abnormalities of biliary function.
  • Lung scans can help detect problems such as blood clots, providing information about oxygen and blood supply.
  • Renal scans can detect kidney tumors, cysts, obstructions, and other problems.
  • Thyroid Uptake scans give important information about the thyroid gland in the neck.


It is important to note that while the nuclear medicine scan itself is a painless exam, it does involve exposure to radiation. However, the benefits of an accurate and early diagnosis far outweigh the risk.

The radioactive materials given during the exam are given in tiny amounts with exposure similar to what you would receive with a standard x-ray. They also lose their radioactivity very quickly and pass through the body usually within 24-48 hours.

Before the Exam

A nuclear medicine scan is a safe and patient-friendly exam. We ask that you wear comfortable, loose-fitting clothing, such as a sweatshirt without zippers or snaps. You may be asked to change into a gown, depending on the area of your body to be scanned.

You may be asked to fast before the scan. For some scans, the radiopharmaceutical is administered hours or even days prior to the imaging portion of the scan.

Preparation for your exam will vary according to what area is being tested. Your doctor will give you special instructions prior to your appointment. Please follow them closely.

If you are pregnant or breastfeeding, please alert your technologist. Exams utilizing injected radioactive material are usually not recommended for women who are pregnant or breastfeeding.

If you have questions about a health condition that could affect your exam, please talk to a nuclear medicine physician or technologist.

During the Exam

When you arrive on the day of your appointment, you will meet a technologist who will conduct your nuclear medicine exam.

Your nuclear medicine physician has received extensive training in nuclear medicine tests and treatments, including the areas of anatomy, patient care, radiopharmaceuticals, and the analysis of test results.

Your nuclear medicine technologist has also received specialized training in radiation protection and exposure, as well as preparation and administration of radioactive material, operation of cameras and probes, and measurement of results.

After you change into a gown, if necessary, your technologist will ask you to lie down or sit on a scanning table. Here are some common procedures:

  • Stationary gamma cameras are positioned as close to the body as possible. You will stand, sit, or lie down, depending on the area to be scanned. 
  • SPECT, or Single Photon Emission Computed Tomography, uses a rotating gamma camera that can move during the scan to provide a more complete picture of a particular body part. 
  • PET, or Positron Emission Tomography, requires you to lie on a table during the scan. The table moves through a tube, similar to the process of an MRI.

Your nuclear medicine technologist will administer the radiopharmaceutical in the form of an injection or simply by mouth in a liquid or capsule. Most scans require several different positions to capture several different views of your body. It is important that you remain as motionless as possible during each scan.

After the Exam

Most of the low-level radiopharmaceutical will be excreted by your body naturally over the next 24-48 hours. Drink plenty of water to help clear the material from your system more quickly. You do not need to avoid contact with others during this time, but your doctor may suggest that you take some precautions, such as flushing the toilet twice after use to reduce radiation exposure in your household.

The nuclear medicine physician will review your images and send a report to your doctor, who will notify you of any findings. You may also request to receive your images on CD.

Request an Appointment

To speak to an Imaging Services representative or to schedule an appointment with Imaging Services, please call 214-645-XRAY (9729).