HIGH-RESOLUTION POSITRON EMISSION TOMOGRAPHY WITH A PROTOTYPE CAMERA BASED ON SOLID-STATE SCINTILLATION DETECTORS

The prototype of a high resolution PET camera consisting of two opposite arrays of detectors with independent solid state readout was built and tested. The basic detector unit is the RCA C30994 detector module consisting of two 3×5×20 mm BGO scintillators, each coupled to one silicon avalanche photodiode. The two-dimensional stacking capability of the module allows a high resolution multi-ring detection system to be assembled without crystal coding. The prototype was used to simulate a 31 cm diameter dual ring tomograph suitable for animal studies. Coincident detector pair resolution was measured and the contributions to resolution loss estimated using a platinum sheathed.75 mm 68Ge line source. The intrinsic resolution is 1.9 mm FWHM, 3.5 mm FWTM at the center of the field. The reconstructed point spread function resolution in a stationary mode is 2.3 mm FWHM at the center and 3.1 mm FWHM (tangential), 3.9 mm FWHM (radial) at 5 cm from the center. The axial resolution is less than 3.5 mm FWHM throughout the field. The ring sensitivity for an animal system is 67 Kcps/mCi in air for an axial line source and 3.3 Kcps/µCi/ml for a 10 cm diameter cylinder of 22Na solution. Copyright © 1990 by The Institute of Electrical and Electronics Engineers, Inc.