Silicon photomultiplier modules for MRI-compatible PET

Abstract

Silicon photomultiplier (SiPM) modules were developed for use in positron emission tomography-magnetic resonance imaging (PET-MRI), which is a hybrid medical imaging technology. A PET-MRI is very efficient in the early diagnosis of representative senile diseases, including cancer, Alzheimer's disease, and Parkinson's disease. SiPMs comprise the core image sensor for MR-compatible PET applications since they have a low operational voltage, high gain, good timing resolution, ruggedness, insensitivity to magnetic fields, compactness, and low cost. In PET systems, SiPM microcells can be optimized by making a trade-off between photon detection efficiency (PDE) and dynamic range. The SiPM modules used in this study were fabricated at the National NanoFab Center (NNFC) of South Korea by using a customized CMOS processes. The SiPM modules were evaluated by first packaging them with a cost-effective PCB package instead of with a conventional ceramic package. Measurements on 1,400 SiPMs indicated a uniform breakdown voltage of 20.54 V with a standard deviation of 0.07 V. Moreover, the SiPM modules present a high and uniform energy resolution of 13.6% with a standard deviation of 0.5% at 511 keV with 3×3×20 mm 3 cerium-doped lutetium-yttrium oxyorthosilicate (Lu 2(1−x) Y 2x SiO 5 :Ce, LYSO) crystal coupling. These results indicated that the proposed devices offer adequate performance to form the foundation of an image sensor technology for MRI-compatible PET.

Development of a Position Decoding ASIC for SPECT using Silicon Photomultiplier

“…The shape of a current pulse for a SiPM is shown in figure 2 [3] .The maximum current was set to I dm = 25.5 µA and its decay constant, τ d was equal to 40 ns. These value were obtained with a SiPM at National Nanofab Center [8].…”