Recent Blog Articles
HIV rates rising: Could new forms of PrEP help?
Careful! Scary health news can be harmful to your health
Post-pandemic weight loss: There’s an app for that
Cognitive behavioral therapy for insomnia by telemedicine: Is it as good as in-person treatment?
Prediabetes diagnosis as an older adult: What does it really mean?
Is blood sugar monitoring without diabetes worthwhile?
Large review study finds low risk of erectile dysfunction after prostate biopsy
Does exercise help protect against severe COVID-19?
A new Alzheimer’s drug has been approved. But should you take it?
Need physical therapy? 3 key questions your PT will ask
What Is It?
A radionuclide scan is an imaging technique that uses a small dose of a radioactive chemical (isotope) called a tracer that can detect cancer, trauma, infection or other disorders. In a radionuclide scan, the tracer either is injected into a vein or swallowed. Once the tracer enters the body, it travels through the bloodstream to the organ being targeted, such as the thyroid, heart or bones. Different tracers tend to collect in different organs. The tracer emits gamma rays, which are similar to X-rays. These gamma rays are detected by a gamma camera and analyzed by a computer to form an image of the target organ. Sites of potential problems send out more intense gamma rays and appear as bright spots on the scan. Types of radionuclide scans include PET scans, gallium scans and bone scans.
A radionuclide scan is painless, except for a mild skin prick if the tracer is injected. Once the tracer is given, it takes several hours for the isotope to travel to the target organ. During this time, the patient usually can leave the test facility and return for the scan itself, which can last one to five hours.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.