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Information about nuclear medicine examinations

Nuclear medicine examinations uses radioactive pharmaceuticals. These substances allow the assessment of various bodily functions or can be used to treat conditions such as hyperthyroidism.

The pharmaceutical used in nuclear medicine examination contains a small amount of radioactive material. 

Nuclear medicine examinations help detect changes in organ function and metabolism. Many functional disorders can be identified at a very early stage using nuclear medicine examination. 

Nuclear medicine examination can be used to examine, among other things: 

  • cancer metastasis 

  • anemia 

  • lung and kidney function 

  • blood flow in the heart muscle (myocardial perfusion) 

  • bone metabolism 

  • receptor activity in the brain 

  • various infections 

A typical nuclear medicine examination is a bone scintigraphy, which is commonly used to assess the spread of cancer.  Nuclear medicine examinations can also be combined with computed tomography (CT) or magnetic resonance imaging (MRI).  Nuclear medicine examinations are also performed on children. 

Watch the video: Nuclear medicine examination. The video is produced by HUS and includes subtitles in Finnish, Swedish and English. 

Before the examination, you will receive patient instructions indicating whether any preparation is required. Most examinations do not require special preparation, but some have very specific instructions.

Preparation depends on the type of examination being performed. Read the patient instructions carefully and well in advance to avoid cancellation due to inadequate preparation. 

If you know or suspect that you are pregnant, inform your treating physician or the staff at the time of the examination. Nuclear medicine examination is only performed on pregnant women in exceptional cases. 

You will be administered a pharmaceutical, which contains a small amount of radioactive material. It is usually given intravenously or into tissue, but may also be administered orally or via inhalation.  

Once in the body, the radioactive pharmaceutical travels through normal circulation and metabolism to the target area, organ, or tissue. 

In some examinations, imaging can begin immediately after radioactive pharmaceutical administration. In others, there may be a waiting period of up to three hours to allow sufficient accumulation of the radioactive pharmaceutical in the target area. 

Due to the radioactive pharmaceutical, the target organ emits localized radiation, which can be imaged. Imaging is performed using a gamma camera (whole-body, regional, or tomographic imaging – SPECT) or a positron emission tomography camera (PET). 

Depending on the examination, imaging may last from 10 minutes to 1–2 hours. 

The amount of radioactivity in the administered pharmaceutical is low, and normal interaction with others is safe. The contrast agent is eliminated from the body within a few hours. However, avoid holding small children or infants in your lap for the rest of the day. 

A nuclear medicine specialist analyzes the images, prepares a report, and sends it to the physician who referred you. The physician who referred you for the examination will inform you of the results and discuss further treatment.

Contact your care unit if you do not have a scheduled appointment or call time. 

Although radioactive pharmaceuticals are used in nuclear medicine examination, the radiation dose and any potential risk from radiation are small. The devices that measure radioactive radiation are highly sensitive and can detect very small amounts of radiation. Allergic reactions occur very rarely in nuclear medicine examinations. 

If you have concerns about radiation, you can always ask your treating physician or the examination unit staff for more information. 

Watch the video: Radiation Safety ABC – Nuclear medicine examination. The video is produced by OYS and includes subtitles in Finnish and Swedish. 

Updated 11.4.2025