First achievement of less than 1 mm FWHM resolution in practical semiconductor animal PET scanner

An animal PET scanner using CdTe detectors was developed for the purpose of biomedical study using mice and rats. A spatial resolution of 0.8 mm FWHM within the central 20 mm-diameter of the field of view (FOV) was obtained by small CdTe elements of 1.1 mm×5.0 mm×1.0 mm. This spatial resolution is the first achievement of a practical semiconductor animal PET scanner. The determination of the depth of the γ interaction in the detector was carried out by the use of two detector layers. The FOV is 64 mm in diameter and 26 mm in axis. Fine [18F]FDG images of the heads of a mouse and a rat, where the cerebral cortex, the gray matter and the corpus striatum could be respectively distinguished, were successfully obtained. This work inspires the dawn of the high resolution semiconductor PET scanner age as the next generation.