术中导航伽马相机的开发与性能评估

Development and performance evaluation of a gamma camera for intraoperative navigation application

为满足术中SLN显影应用对高分辨、时效性、低成本、结构紧凑的需求,本文开发了高性能的小型伽马相机。采用闪烁晶体阵列和硅光电倍增器SiPM设计结构紧凑的高分辨像素型探测器。探测器由2个单元组成,每个为50×50的YSO晶体阵列(单个晶体条尺寸为0.8 mm×0.8 mm×6.0 mm),通过4.0 mm厚的光导与8×8的SiPM面阵耦合。为兼顾灵敏度性能指标,相机前端配置与像素型探测器匹配的平行孔准直器。从晶体分辨图可以看出探测器解析出大部分0.8 mm×0.8 mm的YSO像素。通过成像实验对空间分辨和灵敏度进行了评价。结果表明:系统有潜力应用于术中导航SLN活检。

To fulfill the requirements of intraoperative sentinel lymph node(SLN)imaging applications in terms of high resolution,fast temporal response,low cost,and compact structure,a small gamma camera with high detec-tion performance,A compact high-resolution pixelated detector is designed on the basis of scintillation crystal and silicon photomultiplier(SiPM)arrays.The gamma detector comprises two units,and each unit is composed of a pixelated array of 50×50 YSO scintillation crystals with a crystal geometry of 0.8 mm×0.8 mm×6.0 mm.The scin-tillation crystal array is then coupled to an 8×8 SiPM array with 4 mm thick light guide.A parallel-hole collimator matched to the pixelated detector is mounted at the entrance of the camera for good sensitivity performance.The flood histogram reveals that most of the 0.8 mm×0.8 mm YSO pixels can be resolved by the detector.The spatial resolution and sensitivity of the system are evaluated by imaging experiments.Results confirm that the system is promising for intraoperative navigation of SLN biopsy.