A gamma-ray imager with multiplexer readout for use in ultra-high-resolution brain SPECT

An ultra-high-resolution single photon emission computed tomography (SPECT) system for brain imaging is discussed. The system uses a multiple-pinhole aperture and many modular detectors, each composed of an array of semiconductor detectors read out by a monolithic integrated circuit called a multiplexer (MUX). The modular detectors, being passive integrators can detect individual gamma rays with good energy resolution. They will also have submillimeter spatial resolution and high count-rate capability. The basic concept of these detectors is described, and some of the design considerations for them are reviewed. Some preliminary experiments are reported that demonstrate that semiconductor detectors with multiplexer read-out act as gamma ray detectors. >