Diagnostic Radioisotopes 

Nuclear medicine uses radioactive isotopes to diagnose disease.  Nuclear medicine imaging produces diagnostic images by detecting radiation within the body. Where does that radiation come from? It’s emitted by small amounts of diagnostic radioisotopes or radioactive tracers introduced into the body. The tiny amounts of radiation these isotopes emit can be traced and used to help a doctor see how an organ is functioning. This allows the doctor to make a diagnosis and suggest appropriate treatment for a patient.  

Conditions Treated 

Diagnostic radioisotopes are used to diagnose conditions such as: 

  • Cancer  
  • Heart disease 
  • Lung disorders 
  • Blood disorders 
  • Gallbladder disease 
  • Bone fractures and infections 
  • Thyroid disease, including hypothyroidism 
  • Kidney disease, including infections, scars or blockages 

Procedure Details 

How you are asked to prepare for a diagnostic radioisotope imaging test will depend on the type of test you’ll be given. In some cases, you may not be allowed to eat or drink for six hours before the test until it’s completed. In other cases, there are no restrictions.  

Radioisotopes can be administered orally, intravenously, or through inhaling. Then the nuclear imaging scan will typically follow this process: 

  • You will be asked to lie still on an examination table under a gamma camera.  
  • The camera will take a number of pictures.  
  • Crystals inside the camera will detect radiation coming from the body and form the images around the radiation.  
  • The images are interpreted by nuclear medicine doctors who are trained to identify abnormalities or disease before making a diagnosis.  

What to Expect 

Most imaging with diagnostic radioisotopes lasts less than one hour, not including the time it takes for the tracer to be absorbed by the body. However, some nuclear medicine studies can take longer than an hour or require more than one visit.  

There is no need to be concerned about diagnostic radioisotopes in terms of radiation, levels of which are typically very low. Risks for complications usually only involves allergies to tracers.  

You can resume your normal daily activities and diet immediately following a nuclear imaging test.  


Imaging using diagnostic radioisotopes is safe and effective and offers one of the least invasive ways to diagnose conditions. Oftentimes, other types of testing cannot provide the information that a nuclear medicine scan can.  

At Tampa General Hospital, our expert nuclear medicine physicians and radiologists perform diagnostic radioisotope imaging to ensure our patients receive world-class care that is specific to their individual needs.