By Joy Johnson, CNMT
Nuclear Medicine - Lead Technologist, Blanchard Valley Health System

Nuclear medicine testing is a branch of medical imaging that uses small amounts of radioactive materials, called radiopharmaceuticals, to provide information about the physiological function of tissues and organs, such as blood flow, metabolism, and biochemical processes. This can be particularly useful in diagnosing certain diseases, monitoring treatment responses, and assessing disease progression. Other imaging modalities like X-rays, CT scans, and MRI primarily provide structural images of the body.

Radiopharmaceuticals are drugs containing radioactive isotopes. These isotopes emit gamma rays that are detected by specialized cameras. In contrast, other imaging modalities use external sources of energy (X-rays, magnetic fields, etc.) to create images. The amount of radiation used in nuclear medicine tests is considered safe for patients. However, pregnant or breastfeeding women are typically advised to avoid these tests unless absolutely necessary.

Depending on the specific test being completed, healthcare providers will give instructions on steps to take for preparation. These may include fasting, drinking plenty of water, or discontinuing certain medications. It is essential to follow these instructions carefully to ensure the accuracy of the test.
The radiopharmaceutical is administered either through an injection into a vein, ingestion as a liquid, or inhalation as a gas. The specific method depends on the type of test and the organ or tissue to be studied. After the patient receives the radiopharmaceutical, there may be a waiting period before the imaging procedure begins. This allows time for the radiopharmaceutical to circulate and accumulate in the target tissue or organ. 

The imaging procedure is started once the radiopharmaceutical has had time to distribute through the body. Typically, imaging is completed while lying on a scanning table, and a gamma camera or PET scanner is positioned over or around the patient. The camera will capture images of the distribution of the radioactive material within the body. During the scan, the patient will need to remain as still as possible to ensure clear images. The duration of the imaging procedure can vary depending on the specific test being performed. Some scans may take only a few minutes, while others may take longer. In most cases, normal activities can be resumed immediately after the test. 

Nuclear medicine has unique applications, including thyroid imaging and therapy, myocardial perfusion imaging for evaluating heart function, bone scans for detecting fractures and tumors and neuroimaging for assessing brain function and neurological disorders. Other imaging modalities have their own specific applications, such as X-rays for bone fractures and CT scans for detailed anatomical imaging of various body parts.

In some cases, nuclear medicine techniques can be combined with other imaging modalities for more comprehensive assessments. For example, PET-CT combines PET with CT imaging to provide both functional and anatomical information in a single examination. Overall, nuclear medicine complements other imaging modalities in radiology by providing unique insights into tissue function and physiology, thereby enhancing the diagnostic and therapeutic capabilities of modern medicine.