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内容記述 |
The multiplexing technique is essential to reduce the complexity of clinical positron emission tomography (PET) systems. In this study, we developed a diode-based row column multiplexing circuit dedicated to the TOFPET2 ASIC module for our next generation whole gamma imaging (WGI) systems. The WGI systems consist of dual detector rings, and we used two different detector designs, the one-to-one coupling detector with time-of-flight (TOF) capability for the outer ring and the crosshair light sharing (CLS) detector with both TOF and depth-of-interaction capability for the inner ring. The one-to-one coupling detector consisted of an 8×8 array of fast-LGSO crystals (3.1×3.1×20 mm3) and an 8×8 silicon photomultiplier (SiPM) array (Hamamatsu, S14161-3050HS). The CLS detector consisted of a 14×14 array of fast-LGSO crystals (1.45×1.45×15 mm3) and the same type of 8×8 SiPM array. The TOFPET2 ASIC module was used for data acquisition. For coincidence detection, a pair of two identical detectors was used. Two types of row-column multiplexing circuits with a diode and a resistor were developed. For the one-to-one coupling detector, the coincidence timing resolution (CTR) were degraded about 18% and 45% with the diode and resistor multiplexing, respectively. For the CLS detector, the CTR was degraded about 23% and 51% with the diode and resistor multiplexing, respectively. In conclusion, the diode-based multiplexing enhanced the CTR compared to that of the resistor-based multiplexing. In the future, we plan to investigate the optimal diode model to further improve the CTR. |
