【摘要】 目的 单晶体γ相机测试标准中平面系统空间分辨率和灵敏度不能有效反映准直器的质量问题,需寻找更好的方法进行准直器验收测试。方法 通过测试20只平行孔准直器平面系统均匀性,并辅以测试断层均匀性和直接观察准直器内部结构,对准直器进行验收。结果 平面系统均匀性是检测准直器的有效指标。对于系统泛源图像出现较明显非均匀区域,或准直器积分均匀性>3%的准直器为验收不合格。结论 系统均匀性测试为准直器验收中最佳方法。

Li Xiaohua^* , Wu Kenin,Ouyang Xi.

    ^* Department of Nuclear Medicine, Guangzhou Military General Hospital,Guangzhou, 510010

【Abstract】 Purpose In the acceptance of twenty parallel hole collimators, 30 percentof them were found with quality faults. The test items including two NEMA cameraperformance, system spatial resolution and sensitivity, are not enough to evaluate theperformance of collimator, especially to find quality faults in collimator. We have triedthree other test items to search for an effective method for the checking beforeacceptance of collimators. Methods The test items included: ①the system uniformity, ②the reconstruction uniformity, and ③the physical check on interior components and structure ofcollimators. Results Onitem 1, the images obtained from all failed collimators appeared obvious nonuniformity. Onitem 2, circular artifacts on the images could be found only in collimators with seriousfaults. On item 3, covers of six collimators were removed, most of the faults could befound directly. Conclusions The system uniformity is the most effective test. A collimatorshould be rejected, if its image appears any obvious nonuniformity, and/or the collimatorintegral uniformity 〔=(system integraluniformity)-(intrinsic integral uniformity)〕>3%.

     ......