Health Topic

Nuclear Scans

Nuclear scans use radioactive substances to see structures and functions inside your body. Read about how the test is used and what to expect.

Reviewed Reviewed by a registered pharmacistGeneral information

Also called: Radioisotope scans · Radionuclide scans

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Nuclear Scans

A nuclear scan is a type of medical imaging test that uses a small amount of radioactive material, called a radiotracer. This scan shows how organs and tissues are working, not just what they look like.

After the radiotracer is given, a special camera detects the radiation coming from inside the body. This allows your health care provider to see organ function, blood flow, or tissue activity, which can help diagnose conditions and check how well treatment is working.

Nuclear scans may be used to find disease, target certain cells, and monitor response to treatment. They are commonly used to:

  • Check how organs such as the heart, lungs, or kidneys are working
  • Find disease early, sometimes before changes can be seen on other imaging tests
  • Perform bone scans
  • Evaluate the thyroid
  • Check how well cancer treatment is working

Before the scan, you will receive a small amount of radiotracer. This may be given as:

  • An injection
  • A pill or liquid to swallow
  • A gas to inhale

The radiotracer travels to the part of the body being examined. How much of the tracer is absorbed can help show how well an organ or tissue is functioning.

Always tell your provider if you are pregnant, think you may be pregnant, or are breastfeeding.

You may be asked to change clothes and remove jewelry or other items that could interfere with the scan. Ask your provider if there are any special instructions before your scan.

Depending on the type of nuclear scan, you may:

  • Lie on a table
  • Sit in a chair
  • Stand
  • Walk on a treadmill or ride a stationary bike (for some heart scans)

You will be asked to stay as still as possible, unless movement is part of the test.

A special imaging device, such as a gamma camera, single-photon emission computed tomography (SPECT) scanner, or positron emission tomography (PET) scanner, detects radiation from the tracer and creates images.

The length of the scan depends on the type of test and the area being examined. Some scans take only minutes. Others may include waiting periods or require you to return later the same day or over several days.

Most people can return to normal activities right away. Drinking fluids may help your body clear the radiotracer.

A specialist called a radiologist reviews the images and shares the results with your provider.

It sits within Diagnostic Tests.

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Research on Nuclear Scans

349 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

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Prevention and Risk Factors

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Radionuclide Imaging. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Nuclear Scans, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.