Discovery LS PET/CT的验收及性能评估

Acceptance tests and performance evaluation for Discovery LS PET/CT

目的 全面评估DiscoveryLSPET CT的性能指标。方法 PET CT验收包括CT性能测试、PET性能测试及图像融合精度测试。CT性能测试采用陕西省疾病控制中心“CT验收标准” ,模型为美国体模实验室生产的CT专用模型。PET性能测试采用美国全国电子工厂协会 (NEMA)标准 ,模型为NEMAPET标准模型 (1994年版 )。结果 CT定位光及床精度偏差为 0 ,CT值 0 7,噪声 3 5 8,空间分辨13lp cm ,对比分辨 3mm。PET横向空间分辨半高宽 (FWHM)为 4 33mm ,灵敏度 0 15 7·s- 1 ·Bq- 1 ·ml- 1(二维 ) ,散射分数 11 16 % (二维 ) ,散射分数校正精度 1 37% ,均匀性 7 4 4 %。Jaszczak模型可分辨7 9mm圆柱及 9 5mm圆球 ,均匀性良好。结论 该PET CT的性能指标达到出厂要求 ,个别指标误差 <10 % ,通过验收。

Objective To evaluate the performance specification of Discovery LS PET/CT through the acceptance tests. Methods Acceptance tests of PET/CT consists of: CT performance measurements,PET performance measurements and the precision measurement of imaging fusion. The performance measurement of CT was based on the standard of Xi'an CDC CT Acceptance Test Program,and PET on NEMA standard (1994 version). The CT phantom used was produced by The Phantom Lab,USA and PET phantom used was the NEMA standard phantom. Results Accuracy error of laser localization and bed movement was 0,CT value o.7, noise 3.58,spatial resolution 13l p/cm and contrast resolution 3 mm. Transverse resolution of PET was 4.33 mm FWHM,sensitivity 0.157·s -1 ·Bq -1 ·ml -1 for 2D,scatter fraction (SF) 11.16% for 2D,the accuracy of SF correction 1 37% and uniformity 7.44% . The Jaszczak phantom imaging can recognize 7.9 mm rod and 9.5 mm sphere. The uniformity of the phantom imaging is acceptable. Conclusion The measurement results met the requirement of manufacture's standards,some parameter errors are less than 10%,therefore acceptance test was approved.