General nuclear medicine is a small field of medicine contained within the larger field of medical imaging. Its primary characteristic is that the patient has to receive a small dose of radioactive material prior to a scan being performed, and it is this radioactivity that the scan uses to form an image. Doctors and medical professionals can often diagnose illnesses such as tumors and broken bones through this method, or assess the health of areas of the body. Some conditions are also directly treatable with radioactive material.
In all general nuclear medicine techniques, unstable molecules that produce radioactive energy are essential materials. Radioactivity is not usually present in a patient. When a doctor adds radioactivity to the body of a patient, it congregates in certain areas. Which area the substance collects in varies according to the chemical itself. This propensity for the radioactive substance to accumulate in specific places is extremely useful for the doctor, for both diagnosis and medical treatments.
Doctors can assess the way a body functions through general nuclear medicine scans. If a person has abnormally narrow arteries as a result of cardiovascular disease, for example, a scan that looks at the movement of the chemical through the circulatory system can highlight problem areas. Blood flow issues are also important for stroke patients, or those at risk of stroke.
Sometimes, organs can leak or bleed, and the presence of radioactivity in areas where it should not be can flag these problems. Organs that produce hormones, like the thyroid, can also have their production judged by the amount of radioactivity associated with the area. Whether an organ such as a kidney is clearing urine correctly may also be assessed. Tumors can also attract certain radioactive materials, and the radiation energy can help the doctor pinpoint the tumor mass. If a patient's bone is broken, the general nuclear medicine scan can often identify the break area.
As well as finding uses in the medical imaging arena, a doctor can also use general nuclear medicine as part of a treatment regimen for several types of disease. In these situations, such as tumor treatment, the radioactivity of the substance the patient receives is dangerous to cells. With medical imaging, the radiation poses little risk to the health of the patient. The radioactive medicine has a particular affinity for cancer cells, and selectively targets these for radiation destruction.