A GAMMA-RAY IMAGER WITH MULTIPLEXER READ-OUT FOR USE IN ULTRA-HIGH-RESOLUTION BRAIN SPECT

We are developing an ultra-high resolution SPECT system for brain imaging. 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 dew individual gamma rays with good energy resolution. They will also have sub-millimeter spatial resolution and high count-rate capability. In this paper we describe the basic concept of these detectors and review some of the design considerations for them. We also report some preliminary experiments that demonstrate that semiconductor detectors with multiplexer read-out act as gamma ray