Nuclear Medicine is a branch of medicine that uses radioactivity for diagnosis and therapy. It started in the mid-1920s when German scientists experimented with radionuclides on rats.
Tracers (pharmaceuticals labelled with radiation emitting isotopes or radionuclides) are administered to patients (either intravenous, orally, inhalation, subcutaneously/subdermally) and the radiation emitted is detected by scintillation cameras (gamma cameras or PET cameras) and images are produced from this, depicting the distribution of the tracer within the body.
Radiopharmaceuticals are administered (usually intravenously) to treat disease with curative or palliative intent. They act by killing abnormal cells within the body by high but localized radiation exposure (akin to targeted internal radiation).
PET/CT, a hybrid imaging technique, combines functional/physiologic imaging with the more traditional anatomic/structural imaging. By providing the best of both worlds, it has played a pivotal role in ushering in the new era of Molecular Imaging, to go hand in hand with Molecular Medicine in the 21st century.
Society of Nuclear Medicine and Molecular Imaging (SNMMI) http://www.snmmi.org/
India (SNM-I) http://www.snmindia.com