DOI Self-Calibration Method Based on Intrinsic Radiation for Positron Emission Tomography

作者：Xin Yu, H. Zou, Han Liu, Zhijun Zhao, D. Liang, Xiaoyin Zhang, Huiping Zhao, Jinyong Tao, Wen-Jing Zhu, Yibin Zhang, Jiayang Zeng, Xiaoying Tang, Jianfeng Xu, Qiyu Peng · 发表于：IEEE Transactions on Radiation and Plasma Medical Sciences · 年份：2026 · DOI：10.1109/trpms.2025.3602383 · 被引用次数：1

depth of interaction (DOI) decoding can reduce localization errors in the line-of-response (LOR), thereby improving positron emission tomography (PET) image quality, especially in high-resolution PET, long-axial PET, and small-aperture PET systems. Current PET detectors are capable of achieving high-resolution DOI decoding, but most methods rely on collimation calibration for each detector. Calibrating all detectors is labor-intensive and complicates subsequent system maintenance. We aim to achieve DOI collimation for PET detectors based on the intrinsic radiation of 176Lu, which allows us to omit the complex step of calibrating DOI for all detectors. This approach allows DOI calibration to be performed automatically during each system operation, simplifying system maintenance. The pixelated LYSO detector in this study consists of LYSO pixels with dimensions of $ 2 \times 2 \times 20 \, \text {mm}^{3} $ . The detector is arranged in an $8\times 10$ array configuration. We obtained the relationship between intrinsic radiation and DOI through Monte Carlo simulations, and the relationship between the multi pixel photon counter (MPPC) signal ratio (the relative proportion of light detected by different MPPCs from the same crystal, which changes with DOI) and intrinsic radiation through experiments. This allowed us to establish a conversion function between DOI and the MPPC signal ratio. We verified the DOI resolution through collimation testing and demonstrated the improvement in...