论文标题
一对一耦合宠物探测器的基于FPGA的能量校正方法：模型和评估
An FPGA Based energy correction method for one-to-one coupled PET detector: model and evaluation
论文作者
论文摘要
基于硅光电培养基（SIPM）的PET扫描仪已被广泛用作一种先进的核医学成像技术，可产生体内生物学和生物化学区域的定量图像。 SIPM的紧凑尺寸允许闪烁晶体和光电传感器之间的直接一到一对耦合，比必须在光电倍增管（PMT）宠物系统中使用的光共享方法产生更好的计时和能量分辨率。为了减少读出电子设备的量，具有位置解码器的前端多路复用器是一对一系统的共同选择，而没有高度集成应用程序特定的集成电路（ASIC）。但是，在这种情况下，我们无法测量受歼灭光子启发的每个晶体沉积的能量，因此晶体间散射（ICS）事件将导致晶体误差，然后降低检测器的内在分辨率。此外，考虑到sipms增益分散和非线性输出所产生的能量窗口内的事件排斥，需要一种能量校正机制。然而，缺乏每种晶体能量的信息将为ICS事件带来较大的能量校正误差。对于此问题，本文介绍了在Kintext-7现场可编程栅极阵列（FPGA）设备上实施的在线能源校正机制。实验室中的实验是使用8 x 8分段的溶血晶体与8 x 8 SIPM（J系列，来自on的半导体）阵列进行的，该阵列低于22Na点源激发。测试结果表明，非技术事件的能量和ICS事件的能量都可以得到精确校正，并且能量分辨率优于12％。我们还将此方法应用于68GE线源的实际临床PET扫描仪，以验证其多通道可靠性。
A PET scanner based on silicon photomultipliers (SiPMs) has been widely used as an advanced nuclear medicine imaging technique that yields quantitative images of regional in vivo biology and biochemistry. The compact size of the SiPM allows direct one to one coupling between the scintillation crystal and the photosensor, yielding better timing and energy resolutions than the light sharing methods that have to be used in photomultiplier tube (PMT) PET systems. To decrease the volume of readout electronics, a front end multiplexer with position decoder is a common choice for the one to one system without a highly integrated application specific integrated circuit (ASIC). However, in this case we cannot measure each crystal's deposited energy inspired by an annihilation photon, so the inter-crystal scatter (ICS) events will lead to the crystal mispositioning and then deteriorate the detector intrinsic resolution. Besides, considering the events rejection within the energy window resulting from the gain dispersion and nonlinear outputs of the SiPMs, an energy correction mechanism is needed. Yet, lack of the information of each crystal's energy will introduce large energy correction error for the ICS events. For this issue, an online energy correction mechanism implemented on a Kintext-7 Field Programmable Gate Array (FPGA) device is presented in this paper. Experiments in the laboratory were performed using an 8 x 8 segmented LYSO crystals coupled with an 8 x 8 SiPM (J-series, from ON Semiconductor) array which is under 22Na point source excitation. Test results indicate that both the energy of the non-ICS and ICS events can be precisely corrected and the energy resolution is better than 12 %. We also applied this method to an actual clinical PET scanner under a 68Ge line source to verify its multi-channel reliability.
