High resolution time-of-flight positron emission tomograph

A time-of-flight positron emission tomograph (TOF-PET) was recently developed for the purpose of clinical medical study and brain research. It provides high-quality positron images with a spatial resolution of 8 mm full width at half-maximum (FWHM) which is obtained by the use of time-of-flight (TOF) location techniques and small 10×18-mm BaF₂ detectors to detect the positron-electron annihilation γ-rays. The time-of-flight resolving time was 623 ps (FWHM) in the system, which has improved the S/N ratio for positron images. This new TOF-PET has been designed to digitally record the arriving time of γ-rays at the detectors using the system clock. With this method, the architecture of hard and software for taking TOF sinograms and reconstructing TOF images is simplified compared to that of other TOF-PET systems. The details of this system are described here.