A positron emission tomography scanner system that includes detector modules arranged adjacent to one another to form a cylindrical detector ring. Each of the detector modules includes an array of scintillation crystal elements, a plurality of photosensors arranged to cover the array of crystal elements and configured to receive light emitted from the array of crystal elements, and a fiber optics plate arranged between the array of scintillation crystal elements and the plurality of photosensors, the fiber optics plate including a plurality of fibers configured to guide the light emitted from the scintillation crystal to the plurality of photosensors.