Development of a MR-compatible DOI-TOF detector module for PET imaging systems

Abstract

PET systems are widely used in clinical and preclinical molecular imaging applications. Various PET systems, including whole-body human and small animal PET, and dedicated systems such as breast and brain PET have been developed. A Standardized PET detector module with good performance will make it much easier and more efficient for different kind of PET scanner instrumentation. In this paper, we developed a compact MR-compatible PET detector with DOI and TOF capability. The detector module has staggered 15×15 +16 ×16 LYSO crystal array with single crystal size of 2×2×7mm3. The detector is coupled to SiPM array (MicroFJ-30035-TSV, SensL). The output signals of SiPMs are multiplexed by 64-channel ASIC chips and then digitized by 80MHz 12-bit ADC chips and TDC implemented inside FPGA to generate energy and timing information. The performance of the detector was preliminarily evaluated. A flood image was acquired and all crystals were clearly identified with an average energy resolution of 12.7% for 15×15 array and 14.2% for 16×16 array. About 300 ps coincidence timing resolution was achieved for a pair of single crystal. More accurate energy resolution and coincidence timing resolution for the detector module will be evaluated in the future. And the MR compatibility evaluation of this module is underway. Large quantities of detector blocks will be made and tested to verify the performance stability and reproducibility. Furthermore, we are developing standardized power and signal interface for better usability.