【摘要】 目的　鉴定PET仪的实际使用质量及维护其长期使用的稳定性 ,并为上海市核医学质控中心检测提供依据。方法　应用模型和放射源为 :NEMA标准圆柱模型、可灌注点源、可灌注线源、测试模型内的线源插件 ,测试用的放射源均为18F ,根据测试要求采用不同放射性的18F及68Ga的柱源。结果　测试前对PET仪进行完整的调试和校正 ,包括二维和三维的相对效率变异、能量阈值、支架以及活度仪的调试等。根据Siemens公司提供的测试程序 ,参照NEMA的测试标准 (1994年版 ) ,结果显示二维模式时横向分辨率 (FWHM)在中心点为 4.5 0mm ,距中心点 10cm处为 4.6 3mm ;轴向二维模式的FWHM为 4.0 5mm等。应用三维模式采集时 ,FWHM在中心点为 4.5 3mm ,距中心点 10cm处为4 76mm。二维模式散射分数为 15 .1% ,灵敏度为 6 .16 7+0 5MBq·mL-1·min-1。二维模式采集时体积偏差为 3.6 %。结论　SiemensECATHR+ 型PET仪的性能检测结果与出厂时的测试结果基本相符更多还原

【Abstract】 Objective To evaluate the performance of the high resolution whole body PET scanner ECAT EXACT HR +. Methods The scanner consists of four rings of 72 bismuth germanate block detectors each, covering an axial field of view of 15.5 cm with a patient port of 56.2 cm. A single block detector is divided into an 8×8 matrix, giving a total of 32 rings with 576 detectors each. The scanner is equipped three 68 Ga line sources for transmission scans and daily quality control. The spatial resolution, scanner fraction, count rate, sensitivity and uniformity were evaluated after the National Electrical Manufacturers Association (NEMA) protocol using the standard acquisition parameters. Results The transaxial resolution in the two dimensional mode was 4.50 mm in the center and increased to 4.63 mm at a distance of r=10 cm from the center. The axial slice width measured in the two dimensional mode was 4.05 mm FWHM. In the three dimensional mode the average axial resolution varied between 4.53 mm FWHM in the center and 4.76 mm at r=10 cm. The scatter fraction was 15.1% for a lower energy discriminator level of 350 keV. The total system sensitivity for true events was 6.167+05 MBq·mL -1 ·min -1 for 2D. From the uniformity measurements, we obtained a volume variance of 3.6% for 2D. Conclusions The ECAT EXACT HR + has an excellent, nearly isotropic spatial resolution, which is advantageous for brain and even small animal study. The scanner offers a sufficient sensitivity and count rate capacity for three dimensional whole body imaging. Compared with the performance data provided by the CTI the data of our PET scanner are similar to the CTI data.更多还原