Positron emission mammography using Pr:LuAG scintillator – Fusion of optical material study and systems engineering

The breast cancer is one of the most frequent cause of death among female cancer patients. However, when discovered at the early stage, the probability of recovery is very high. Therefore, the development of positron emission mammography (PEM) to detect the breast cancer at the early stage with high efficiency is demanding. As the diameter of the scanner part is small, a scintillator with faster response is required. As the recently developed Pr:LuAG has almost twice as short scintillation decay time than that of Ce:LSO, the Pr:LuAG scintillator was employed in our recently developed PEM system. One camera unit consisted of 20 × 64 scintillator pixels optically coupled with three H8500-03 multi anode photomultipliers. The Pr:LuAG pixel size is 2.1 × 2.1 × 15 mm3 and the BaSO4 was used as a reflector. Four planar cameras are placed at both sides. Therefore, eight cameras were installed at both sides of the instrument. The spatial resolution was evaluated to be 1.1 mm using the 22Na point source. Fluorodeoxyglucose with 18F hotspot image was also detected using the breast phantom.