Nuclear medicine is a medical specialty that uses radioactive tracers (radiopharmaceuticals) to assess bodily functions and to diagnose and treat disease. Specially designed cameras allow doctors to track the path of these radioactive tracers. Single Photon Emission Computed Tomography or SPECT and Positron Emission Tomography or PET scans are the two most common imaging modalities in nuclear medicine.
Nuclear medicine procedures are used in diagnosing and treating certain illnesses. These procedures use radioactive materials called radiopharmaceuticals. Examples of diseases treated with nuclear medicine procedures are hyperthyroidism, thyroid cancer, lymphomas, and bone pain from some types of cancer.
Nuclear medicine radiologists, also called nuclear radiologists, are physicians who use radioactive materials, called radiopharmaceuticals, to diagnose and treat disease. They employ such techniques as scintigraphy, which uses radiopharmaceuticals to produce images of the body’s organs or to visualize certain diseases.
Very low risk. Because only a small dose of radiotracer is used, nuclear medicine exams have a relatively low radiation exposure. This is acceptable for diagnostic exams. Thus, the radiation risk is very low when compared with the potential benefits.
A nuclear medicine test uses small amounts of a special liquid known as a radiopharmaceutical to look at and to treat diseases. Nuclear medicine tests are safe and give doctors pictures of the human body using a special camera. Other radiology tests, such as MRI and CT scans, take detailed pictures of the body.
SPECT scans are primarily used to diagnose and track the progression of heart disease, such as blocked coronary arteries. There are also radiotracers to detect disorders in bone, gall bladder disease and intestinal bleeding. SPECT agents have recently become available for aiding in the diagnosis of Parkinson’s disease in the brain, and distinguishing this malady from other anatomically-related movement disorders and dementias.
The major purpose of PET scans is to detect cancer and monitor its progression, response to treatment, and to detect metastases. Glucose utilization depends on the intensity of cellular and tissue activity so it is greatly increased in rapidly dividing cancer cells. In fact, the degree of aggressiveness for most cancers is roughly paralleled by their rate of glucose utilization. In the last 15 years, slightly modified radiolabeled glucose molecules (F-18 labeled deoxyglucose or FDG) have been shown to be the best available tracer for detecting cancer and its metastatic spread in the body.
A combination instrument that produces both PET and CT scans of the same body regions in one examination (PET/CT scanner) has become the primary imaging tool for the staging of most cancers worldwide.
Recently, a PET probe was approved by the FDA to aid in the accurate diagnosis of Alzheimer’s disease, which previously could be diagnosed with accuracy only after a patient’s death. In the absence of this PET imaging test, Alzheimer’s disease can be difficult to distinguish from vascular dementia or other forms of dementia that affect older people.
Writer: Jayeola Mathew（Harbin Engineering University）
Editor: Priscilla Oforiwaa
Designers: Zhang Jing & Zhang Chao
Translation : Zhang Chao