Publications by authors named "Hyeong Seok Shim"

Inter-crystal scattering (ICS) events in Positron Emission Tomography (PET) present challenges affecting system sensitivity and image quality. Understanding the physics and factors influencing ICS occurrence is crucial for developing strategies to mitigate its impact. This review paper explores the physics behind ICS events and their occurrence within PET detectors.

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Identifying the inter-crystal scatter (ICS) events and recovering the first interaction position enables the accurate determination of the line-of-response in positron emission tomography (PET). However, conventional silicon photomultiplier (SiPM) signal multiplexing methods based on two-dimensional (2D) charge-division circuits do not allow the detection of multiple gamma-ray interaction positions in a scintillation array coupled with a SiPM array. In this study, we propose a novel multiplexing method that can restore all the individual channel data from a smaller number of multiplexed channels using high-pass filters and neural networks.

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In this study, we propose a simple gain compensation technique for silicon photomultiplier (SiPM)-based positron emission tomography detectors, using a temperature sensor that automatically controls the bias voltage of the SiPM depending upon the ambient temperature. The temperature sensor output, for which the temperature coefficient can be controlled by the input voltage, is used as one end of the bias voltage. By adjusting the temperature coefficient, the proposed gain compensation method can be applied to various SiPMs with different breakdown voltages.

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