Continuous LYSO-SSPM array based PET detectors for clinical and small volume imaging studies

Abstract

We are developing a large area thick continuous LYSO-solid state photomultiplier (SSPM) array based PET detectors to exploit the potential applications in clinical and small volume imaging studies. The PET detector design for clinical applications consists of a 47x47x14 mm 3 slab of LYSO crystal sandwiched between two 8x8 element SSPM arrays with 5x5 mm 2 elements. The detector module for higher resolution, small volume imaging studies consists of a thin sheet -5-10mm of L YSO scintillator sandwiched between two 12x12 element SSPM arrays with 1.5x1.5 mm 2 elements. Towards addressing this goal, here we present the construction and evaluation of 8x8 element SSPM array with each element being 5mm x 5mm in size. The SSPM array with an imaging area of 47x47 mm 2 was created by close-tiling RMD's 2x2 array of 5x5 mm 2 SSPM chips in a 4x4 format. Pixel uniformity, energy resolution and timing resolution for individual pixels in the 8x8 array was studied by coupling a single L YSO crystal measuring 3x3x15 mm 3 to each SSPM pixel in the array. The measured photopeak amplitude for 511 keY gamma-rays varied from 66 to 100 over the array. The energy resolution for all pixels in the array ranged from 10% to 12.5% (FWHM). The measured timing resolution for all pixels was in 700ps to 800ps range. Continuous crystal based PET module was also built by coupling a 47x47x8 mm 3 slab of polished LYSO crystal to the 8x8 SSPM array. The energy resolution measuredin the center of the crystal was 16.4% (FWHM) and at the edge it was 16.8% (FWHM). The coincidence timing resolution measured against LYSO-PMT detector was 1.lns in the center and 1.3ns at the edge of the crystal. We also discuss the performance of a monolithic 6x6 SSPM array with each element 1.5mm x 1.5mm for smaller volume, higher resolution PET detectors. The energy resolution for all pixels in the array ranged from 13% to 15%. The measured timing resolution for all pixels was in the range of 500ps to 550ps.

Evaluation of Matrix9 silicon photomultiplier array for small‐animal PET

“…Single channel SiPM detectors, coupled one-to-one to scintillation crystals, have rapidly demonstrated the potential of SiPM-based PET scanners. 5,6 Recently there has been significant academic and industrial development of large area multichannel SiPM technologies [7][8][9][10][11][12][13][14][15][16][17][18][19][20] giving rise to many SiPM-based detector and scanner designs. Besides developing new high performance devices, large-area SiPM modules are also being developed, and some of these modules now include the readout electronics to facilitate the fabrication of PET scanners.…”