中文摘要：

目的：研究并分析拥有飞行时间（TOF）技术的PET／CT相关性能。方法：参照美国国家电气制造协会（NEMA）NU2—2007标准和厂家测试手册，对PET／CT的能量与时间分辨率、空间分辨率、灵敏度、散射分数、计数特性和图像质量进行性能测试和分析，并对不同型号仪器的性能进行比较，初步探讨飞行时间（TOF）技术对设备性能的影响。结果：系统的能量分辨率和时间分辨率分别为11．59％和499．3ps；空间分辨率在1cm处为4．54mm（横向）和4．85mm（轴向），10cm处为5．13mm（横向径向）、5．55mm（横向切线）和5．76mm（轴向）；中心和偏离中心10cm处的灵敏度分别为6．4和6．8（c!os／kBq）；散射分数为32％；等效噪声计数率（NECR）在14．03kBq／ml时达到峰值为97．6kcps；模体图像中可以清楚分辨直径为10mm的最小热球。结论：拥有飞行时间技术的PET／CT各项性能指标都很优越，尤其在于图像质量的提高，可以缩短采集时间和减少注射药物剂量。

英文摘要：

Objective： The performances of a PET/CT scanner with time-of-flight （TOF） capability were measured and studied. Methods： Performances measurements on the scanner were made using the National Electrical Manufactures Association （NEMA） NU2- 2007 procedures and Company＇s Performance Test Manual. The energy/timing resolution, spatial resolution, sensitivity, the scatter fraction, counts performance and imaging quality were measured and analyzed. Different types of PET/CT were compared and the imagingcapabilities of TOF were discussed. Results： The system and 499.3 ps. The transverse and axial resolutions near energy and timing resolution were measured to be 11.59% the center were 4.54mm and 4.85mm, whereas at 10 cm were 5.13 mm, 5.55 mm, 5.76 mm. The absolute sensitivity of this scanner was 6.4（center） and 6.8（10 cm） cps/ kBq, whereas scatter fraction was 32%. The peak NECR was 97.6kcps and occured at 14.03kBq/mL. Image quality measurements with phantom showed that the 10 mm diameter lesion could be clearly distinguished. Conclusion： The PET/CT which achieved TOF capability performed good characteristic, especially in the improvement of image quality. And shorter scan times and lower dose could be gained at the same image quality.