Medical Physics Department, Azienda Ospedaliero Universitaria Maggiore della Carità, Cso Mazzini 18, 28100 Novara, Italy.
Phys Med. 2012 Jul;28(3):210-20. doi: 10.1016/j.ejmp.2011.07.002. Epub 2011 Jul 23.
PET scanners require routine monitoring and quality control (QC) to ensure proper scanner performance. QC helps to ensure that PET equipment performs as specified by the manufacturer and that there have not been significant changes in the system response since acceptance. In this work we describe the maintenance history and we report on the results obtained from the PET system QC testing program over 5 years at two centers, both utilizing a Siemens Biograph 16 HiRez PET/CT system. QC testing programs were based on international standards and included the manufacturer's daily QC, monthly uniformity and sensitivity, quarterly cross-calibration and annual resolution and image quality. For the Winnipeg and Novara sites, two and one PET detector blocks have been replaced, respectively. Neither system has had other significant PET system related hardware replacements. The manufacturer's suggested daily QC was sensitive to detecting problems in the function of PET detector elements. The same test was not sensitive for detecting long term drifts in the systems: the Novara system observed a significant deterioration over five years of testing in the sensitivity which exhibited a decrease of 16% as compared to its initial value measured at system installation. The measure of the energy spectrum, showed that the 511 keV photopeak had shifted to a position of 468 keV. This shift was corrected by having service personnel perform a complete system calibration and detector block setup. We recommend including tests of system energy response and of sensitivity as part of a QC program since they can provide useful information on the actual performance of the scanner. A modification of the daily QC test by the manufacturer is suggested to monitor the long term stability of the system. Image quality and spatial resolution tests have proven to be of limited value for monitoring the system over time.
正电子发射断层扫描（PET）扫描仪需要进行常规监测和质量控制（QC），以确保其性能正常。QC 有助于确保 PET 设备符合制造商的规格，并且自验收以来，系统响应没有发生重大变化。在这项工作中，我们描述了维护历史，并报告了两个中心在 5 年期间使用西门子 Biograph 16 HiRez PET/CT 系统进行的 PET 系统 QC 测试计划的结果。QC 测试计划基于国际标准，包括制造商的日常 QC、每月的均匀性和灵敏度、每季度的交叉校准以及每年的分辨率和图像质量。对于温尼伯和诺瓦拉站点，分别更换了两个和一个 PET 探测器模块。这两个系统都没有其他重要的与 PET 系统相关的硬件更换。制造商建议的日常 QC 对检测 PET 探测器元件功能问题很敏感。但同样的测试对检测系统的长期漂移不敏感：在五年的测试中，诺瓦拉系统的灵敏度观察到显著恶化，与系统安装时测量的初始值相比，灵敏度下降了 16%。能量谱的测量表明，511keV 光峰已移至 468keV 的位置。服务人员通过执行完整的系统校准和探测器模块设置来纠正这一移位。我们建议将系统能量响应和灵敏度测试纳入 QC 计划，因为它们可以提供有关扫描仪实际性能的有用信息。建议制造商修改日常 QC 测试，以监测系统的长期稳定性。图像质量和空间分辨率测试已被证明在长时间监测系统方面价值有限。
