An overview on nuclear medicine

An overview on nuclear medicine Nuclear medicine is a branch of medical procedures in diagnosing, medical imaging, and treating certain medical conditions and diseases, using small amounts of radioactive materials. Diagnosing procedures via nuclear medicine imaging are painless, less invasive for the patient than exploratory surgery, and less expensive. Nuclear imaging offers the ability to precisely locate and identify any abnormalities within the body on a molecular level, and, therefore, can identify diseases in their earliest stages, often before symptoms occur. The radiopharmaceuticals, or radiotracers, used in these procedures are usually injected, swallowed, or inhaled, and the emissions, high-frequency electromagnetic radiation (gamma rays) (Hewitt, 2007), of these substances are detected by a special camera or imaging device, such as PET, CT or MRI. These procedures are also used to evaluate and control a patient’s response to therapies and treatments. The main difference to other imaging and treatment options nuclear medicine offers is the chance to observe physiological body processes in real time, such as heart rate, blood flow, and metabolic processes, instead of solely focusing on anatomical and structural features (RSNA, 2013). Nuclear imaging is mostly used to detect cancer, bone tissue defects, and to observe organ or other metabolic functions of the body (Argosy, 2013). In order to perform nuclear medicine imaging, the radiotracer needs to be placed in the patient’s body. This is usually done on an outpatient basis, unless the patient is already hospitalized. A common medical history as well as the patient’s current medical condition, incl. current medication or supplement and vitamin intake, is required. Depending on the radiopharmaceutical used and how long it takes the material to travel through the body and accumulate in the desired area (organ or tissue), the imaging process may be done immediately or in any timeframe from a few hours up to several days after the administration of the radioactive material. The length of the procedure itself can vary from 20 minutes to several hours (RSNA, 2013). Overall, nuclear medicine imaging can be very time consuming, and the equipment necessary for “taking the pictures” is expensive and voluminous. A very precise and sophisticated diagnostic technique used in nuclear imaging is Positron Emission Tomography (PET), which produces images of the body by detecting gamma rays emitted from the radiotracer (World Nuclear Association, 2011). The location for PET scans is limited by the necessity of a nearby particle accelerator device, which produces the short–lived, radioactive isotopes that are needed to mark the radiotracer (Freudenreich, 2011). The radioactive substance is administered by injection to the patient, who is then placed on a flat table that moves through a donut shaped housing, which contains the gamma ray detectors, each connected to a photomultiplier tube via scintillation crystals. These crystals convert the detected gamma rays into photons of light, which are again converted into electrical signals. A computer processes the signals and generates images. Because of the moving table and the circular arrangement of the detectors, several series of thin slice images of the studied area are the result, which can be assembled into a three dimensional illustration (Freudenreich, 2011). A series of images taken over a period of time is able to show any unusual movement patterns or rates of the administered radiotracer, indicating a potential organ malfunction (World Nuclear Association, 2011). Treatments with nuclear medicine allow the precisely accurate placement of the radiopharmaceutical, avoiding any further tissue or organ damage outside the area in need of treatment. The most common diseases treated with nuclear medicine are: Hyperthyroidism (overactive thyroid gland) and