Abstract: A photodetector array readout and dynamic multiplexing method for reducing the overall channel count in a PET scanner system is disclosed. A PET system includes detector modules mounted on a ring-shaped gantry, each module including an array of M×N pixelated scintillators with photosensors attached to each pixelated scintillator on at least one of the top and the bottom surfaces. The multiplexer includes row and column summing, pulse shaping, and dynamic switching circuits multiplexing M×N inputs to a single output representing the energy and timing of the detected radiation. A position encoder is configured to receive outputs from the N+M summing circuits, and determine which pixelated scintillator had a gamma ray interaction. When photosensors are attached on both surfaces, the depth of interaction is determined as well based on the relative strength of the top and bottom surface readouts.

Abstract: A photodetector array readout and dynamic multiplexing method for reducing the overall channel count in a PET scanner system is disclosed. A PET system includes detector modules mounted on a ring-shaped gantry, each module including an array of M×N pixelated scintillators with photosensors attached to each pixelated scintillator on at least one of the top and the bottom surfaces. The multiplexer includes row and column summing, pulse shaping, and dynamic switching circuits multiplexing M×N inputs to a single output representing the energy and timing of the detected radiation. A position encoder is configured to receive outputs from the N+M summing circuits, and determine which pixelated scintillator had a gamma ray interaction. When photosensors are attached on both surfaces, the depth of interaction is determined as well based on the relative strength of the top and bottom surface readouts.

Abstract: A PET scanning system includes a plurality of detector modules, each having an array of pixelated scintillators, the array having N rows of pixelated scintillators, and M columns of pixelated scintillators. Each detector module includes a first set of N light guides optically coupled to the top surface that accumulate optical signals, and a second set of M light guides optically coupled to the bottom surface that accumulate optical signals. Each light guide is coupled to a light sensor which converts optical signals into analog electrical outputs. A processor is coupled to outputs from the first set and the second set, the processor configured to determine which pixelated scintillator within the array had a gamma ray interact therewith, and its depth of interaction, based on the outputs. Thus, gamma ray detection in an array of M×N scintillator pixels is accomplished using only M+N channels.