Nuclear medicine is a medical specialty that uses radioactive tracers (radio-pharmaceuticals) to assess bodily functions and to diagnose and treat disease. Specially designed radiation detectors allow doctors to track the path of these radioactive tracers, when the radioactive isotope emits radiation, it interacts with the scintillation crystals, producing flashes of light that are detected and converted into a digital image. This allows physicians to visualize the distribution of the radio pharmaceutical in the patient's body and assess the function of the targeted organ or tissue.
Scintillation detectors play a major role in non-invasive clinical investigations. Scintillation materials and design options for SPECT use large NaI(Tl) crystals to detect the gamma rays emitted by the radiotracer injected into the patient. Organ-Specific Image focusing on small field of view for cardiac, breast or brain imaging require fine spatial resolution that can be achieved with a specifically designed array using CsI(Tl), BGO, LaBr3(Ce) or LYSO(Ce) crystals. PET needs the high detection efficiency from LYSO(Ce) and BGO. LYSO(Ce) has a shorter decay time which allows higher data rates, shorter scan times and TOF applications.