摘要
目的：分析单光子发射计算机断层显像仪（SPECT）固有均匀性测试时,质量控制点源放射性活度对测试结果的影响,以指导SPECT日常质量控制。方法：0.555~20.35 MBq点源按常规质量控制方法行静态采集（10000 K/探头,各点源采集3次）,记录中心视野（CFOV）积分均匀性（IU）和微分均匀性（DU）,有效视野（UFOV）的IU和DU,比较其平均值。以SPECT仪器操作指南为标准比较检测结果,并进行统计分析。结果：点源活度≤3.7 MBq时,UFOV和CFOV的IU和DU均达到质量控制要求,活度与IU和DU无相关性。当点源活度〉3.7 MBq时,UFOV和CFOV的IU和DU开始出现不符合项,且随着活度增强,不符合质量控制要求项增多,活度与IU和DU显著相关。结论：日常质量控制点源准备时,点源活度可参考操作指南在一定范围内波动,此范围需通过各单位针对不同仪器进行探索性测量获得,以保证适当增加点源活度后对固有均匀性的检测无影响。
Objective： To guide the daily quality control（QC） test, the aim of this study is to analyze the influences of various point source activities on the intrinsic uniformity test of Single Photon Emission Computed Tomography（SPECT）. Methods： Siemens SPECT system with double head was used in this study. The activities of point source were ranged from 555 KBq to 20.35 MBq. Serial static images were collected（10000k counts/head for three times）. Two different uniformity parameters, including integral uniformity（IU） and differential uniformity（DU）, were calculated for both the central field of view（CFOV） and useful field of view（UFOV）. Pearson correlation analysis was applied in statistical study to compare experimental data（mean value） with those on the basis of operation manual. Results： When the activities of point source were within 3.7 MBq（including 3.7 MBq）, the intrinsic uniformity tests of two head passed smoothly and thoroughly. No correlation was found between activities and uniformities. While the point source activities were more than 3.7 MBq, failures of intrinsic uniformity test raised up with activities increasing. The activities and the data of uniformities showed significantly correlation. Conclusion： Depending on the operation manual, the point source activity can fluctuate in a certain range, which is convenient for point source preparation and passed the intrinsic uniformity test efficiently. The range should be acquired after measuring in different SPECT system and is guarantee to fulfill the daily quality control demanding.
出处
《中国医学装备》
2015年第12期52-55,共4页
China Medical Equipment
