High spatial resolution detector using an 8×8 MLS crystal array and a quad anode photomultiplier

A compact and high position resolution detector for whole body PET has been developed using an 8×8 MLS scintillation crystal array and a quad-anode photomultiplier. The scintillation crystal block consists of 64 single crystals with dimensions of 4.67×4.67×30mm³. Light sharing is controlled through the finishes of the crystal surfaces, Teflon reflective layers and a simple thin light guide. The block properties have been characterized using 511 keV gamma rays using Ge⁶⁸. Peaks in the crystal decoding map are well isolated with an average peak-to-valley ratio of 3.17. An energy resolution of 15% FWHM and a timing resolution of 1.2 ns FWHM were obtained.