Data Acquisition, Reconstruction and Display for the Donner 280-Crystal Positron Tomograph

The imaging system for the Donner 280-Crystal Positron Tomograph is described. The architecture of the hardwired data acquisition system (histogrammer) allows a data rate in excess of two million events/second while simultaneously correcting for accidental events. The histogrammer has eight memory cards to allow separate accumulation of time-slices of the cardiac cycle, or multiple-buffering for rapid sequential studies. Transfer time from the double-bussed histogrammer to a disk of the host computer system is less than one second. A hardwired device is able to reconstruct a 256×256 image from 140 angles in less than three seconds, but since calibration and correction for attenuation are presently performed in software, this time is increased to about 10 seconds. Images are displayed on a 256×256 raster scan display system with image manipulation capabilities.