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What is a nuclear medicine test?

A nuclear medicine test is a kind of imaging test that uses small amounts of a radioactive substance, called a radiotracer or radiopharmaceutical, to help create images of structures and processes inside your body.

For a nuclear medicine test, the radiotracer is typically injected, inhaled or swallowed, and then travels through your body and eventually collects in the area under investigation. The radiotracer gives off energy in the form of gamma rays, which are detected by a special camera and then analyzed by a computer to create images.

Physicians use nuclear medicine tests and procedures to visualize the structure and function of an organ, tissue, bone or system in the body and to help diagnose various conditions, including cancer and infection.

Why it’s done

Physicians use nuclear medicine tests to visualize the function of organs, tissues and systems in the body. Among other things, nuclear medicine tests may be used to:

  • Visualize heart blood flow and function
  • Detect coronary heart disease
  • Evaluate damage to the heart after a heart attack
  • Evaluate bones and detect fracture, arthritis, and tumors
  • Investigate abnormalities in the brain in cases of seizure or memory loss
  • Diagnose hyperthyroidism (overactive thyroid)
  • Diagnose hyperparathyroidism (overactive parathyroid glands)
  • Diagnose blood clots in the lungs (pulmonary embolism)
  • Diagnose infections
  • Assess stomach emptying
  • Diagnose gall bladder disease
  • Assess kidney function
  • Determine how advanced a cancer is
  • Plan cancer treatment

Our approach

When it comes to a nuclear medicine test, our subspecialized nuclear medicine radiologists at Northwell Health Imaging are the power behind the exam. Every nuclear medicine test is interpreted by a fellowship-trained radiologist, whose skills have been honed by specialized training and thousands of hours of experience. If you need additional care, your radiologist will work side-by-side with the rest of your care team, collaborating closely to answer your questions and help guide your care.

Northwell Health Imaging offers the largest group of fellowship-trained and subspecialized nuclear medicine radiologists on Long Island, as well as access to all the resources and clinical expertise of New York state’s largest health system. Whether you are here for screening, diagnostic or treatment imaging services, each of our practitioners is committed to providing a caring, comfortable environment and a positive, productive experience.

Risk factors

Nuclear medicine procedures can provide information that may be unattainable using other imaging approaches, and does so at relatively low risk. The radiotracers used for nuclear medicine diagnostic exams are typically administered at a low dose, and therefore are accompanied by relatively low radiation exposure to the patient, in line with other diagnostic exams. Nuclear medicine diagnostic procedures have been used for more than five decades, and no long-term adverse effects have been identified from the low-dose radiation exposure involved in these procedures.

An allergic reaction to the radiotracer is possible but occurs extremely rarely.

Women should inform their physician or nuclear medicine technologist if there is a chance they might be pregnant, or if they are breastfeeding.

Types of nuclear medicine tests

Common types of nuclear medicine procedures include:

  • Bone scan—used to assess a joint replacement; detect cancer, fracture, sports injury or tumor; or evaluate unexplained bone pain
  • Hepatobiliary (gallbladder) scan—used to evaluate gallbladder function
  • Gastric emptying exam—used to measure how quickly food empties from the stomach; performed when a patient has nausea, abdominal pain, vomiting or diarrhea after eating
  • Thyroid uptake and scan—provides information about the structure (size, shape, position) and function of the thyroid gland
  • Thyroid therapy—used to treat hyperthyroidism (overactive thyroid), including Graves’ disease; also used to treat thyroid cancer

What to expect

Most nuclear medicine exams are painless, although if the radiotracer is administered intravenously you may experience slight discomfort as the IV catheter is placed. Depending on the type of exam, the radiotracer may be injected, inhaled or swallowed. The tracer may take seconds, hours or days to travel through your body and collect in the area being studied. As a result, some nuclear imaging tests are performed immediately after administration of the tracer, while for others you may have to return for imaging a few hours or even days after you are given the tracer.

Radiotracers are formulated and ordered specifically for each patient and exam, and must be used within a short window of time. It is important to notify the office 48 hours in advance if you have to cancel or reschedule your appointment.

For the scan itself, you will be asked to change into a gown and lie on a cushioned exam table as the gamma camera takes a series of images. The camera may be in close proximity but will not touch you or surround you. While the camera is taking pictures, you will need to remain still, as any motion will diminish the quality of the images.

How to prepare

Continue taking any prescribed medication unless directed otherwise. Dress in comfortable clothes without metal fasteners, including zippers, buttons or snaps.

Tell your doctor and the technologist performing the exam about any prescription or over-the-counter medications you’re taking, and about any vitamins or herbal supplements. Also let them know if you have any allergies, illnesses or other medical conditions. Tell your doctor if you’re pregnant or might be pregnant, or if you’re breastfeeding.

You may be asked to lie on your back for an extended period of time for the exam. If that could cause discomfort, you may take an over-the-counter pain reliever, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) before the procedure begins.


Unless otherwise directed, you may resume your normal routine after the exam is completed. The tracer will remain in your body for a short time and is cleared through natural functions. Drinking plenty of fluids will help flush it through your system more quickly.


Your nuclear medicine test will be read/interpreted by a subspecialized radiologist and the results will be promptly shared with your physician. Your doctor will determine if any follow up care is needed.

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