SPECT设备固有均匀性和固有空间线性检测条件的探讨

Conditions for the determination of intrinsic uniformity and intrinsic spatial linearity of SPECT

目的 由于现行标准没有规定固有均匀性的检测矩阵,以及为探讨不同源距对固有空间线性的影响,本文用不同的矩阵和不同的源距分别对8台SPECT 16个探头的固有均匀性和固有空间线性进行检测并分析,以确定最佳的检测条件。方法 依据标准《伽玛照相机、单光子发射断层成像设备(SPECT)质量控制检测规范》(WS 523—2019),使用矩阵64×64和矩阵256×256对固有均匀性进行检测;使用1.7 m和3 m的源距对固有空间线性进行检测。结果 用矩阵64×64测固有均匀性时,超过50%的探头检测值更低;用3 m源距检测固有空间线性时,检测值更低的探头比例较多。结论 建议将矩阵64×64作为固有均匀性的检测条件;建议固有空间线性的源距设为1.5 m以上时,应适当放宽合格限值。

Objective To address the absence of matrix specified for the determination of intrinsic uniformity in the current standard,and to investigate the effect of source distances on intrinsic spatial linearity,the intrinsic uniformity and intrinsic spatial linearity of 16 probes in eight SPECT devices were measured and analyzed with different matrices and source distances,in order to determine the optimal measurement conditions.Methods According to the standard Specification for Testing of Quality Control in Gamma Cameras and Single Photon Emission Computed Tomograph(SPECT)(WS 523—2019),the intrinsic uniformity was measured using 64×64 and 256×256 matrices and the intrinsic spatial linearity was measured using of 1.7 and 3 m source distances.Results When intrinsic uniformity was measured with the 64×64 matrix,more than 50%of the probes showed lower values.When intrinsic spatial linearity was measured with the 3 m source distance,more probes showed lower values.Conclusion The 64×64 matrix is recommended for the determination of intrinsic uniformity and a source distance of>5 FOV is recommended for the measurement of intrinsic spatial linearity.