CAJ | 학술논문

目的采用自适应统计迭代重建(ASiR)技术提高PET/CT全身扫描低剂量CT的图像质量.方法采用CT性能模型测量CT值准确度和噪声,对模型进行两次扫描,扫描条件分别为:120 kV、120 mA和120 kV、300 mA.另随机选取行PET/CT扫描的受检者30例,按体重静脉注射18F-FDG 3.70 MBq,PET/CT全身扫描条件为:PET采用三维+飞行时间+点扩展函数重建技术,1.5 min/床位；CT采用螺旋扫描,120 kV,自动曝光控制技术(30～210 mA,噪声指数25).模型图像和患者全身扫描CT图像分别按照常规方法和40％ ASiR方法进行重建.结果模型和临床研究结果表明,ASiR方法获得的模型CT值标准差较常规CT图像重建方法降低了33.0％(t=27.76,P＜0.01),正常组织(脑、肺、纵隔、肝脏和椎体)和病灶(脑、肺、纵隔、肝脏和椎体)CT值标准差平均分别降低了21.08％(t=23.35,P＜0.01)和24.43％(t=16.15,P＜0.01),而肝脏正常组织和肝脏病灶分别降低了51.33％(t=34.21,P＜0.01)和49.54％(t=15.21,P＜0.01).结论采用ASiR技术明显降低了PET/CT全身扫描低剂量CT图像的噪音,提高了CT图像质量,使其适用于定量分析研究和临床应用.
목적 채용자괄응통계질대중건(ASiR)기술제고PET/CT전신소묘저제량CT적도상질량.방법 채용CT성능모형측량CT치준학도화조성,대모형진행량차소묘,소묘조건분별위:120 kV、120 mA화120 kV、300 mA.령수궤선취행PET/CT소묘적수검자30례,안체중정맥주사18F-FDG 3.70 MBq,PET/CT전신소묘조건위:PET채용삼유+비행시간+점확전함수중건기술,1.5 min/상위；CT채용라선소묘,120 kV,자동폭광공제기술(30～210 mA,조성지수25).모형도상화환자전신소묘CT도상분별안조상규방법화40％ ASiR방법진행중건.결과 모형화림상연구결과표명,ASiR방법획득적모형CT치표준차교상규CT도상중건방법강저료33.0％(t=27.76,P＜0.01),정상조직(뇌、폐、종격、간장화추체)화병조(뇌、폐、종격、간장화추체)CT치표준차평균분별강저료21.08％(t=23.35,P＜0.01)화24.43％(t=16.15,P＜0.01),이간장정상조직화간장병조분별강저료51.33％(t=34.21,P＜0.01)화49.54％(t=15.21,P＜0.01).결론 채용ASiR기술명현강저료PET/CT전신소묘저제량CT도상적조음,제고료CT도상질량,사기괄용우정량분석연구화림상응용.
Objective To improve image quality of low dose CT in whole body PET/CT using adaptive statistical iterative reconstruction (ASiR) technology.Methods Twice CT scans were performed with GE water model,scan parameters were:120 kV,120 and 300 mA respectively.In addition,30 subjects treated with PET/CT were selected randomly,whole body PET/CT were performed after 18F-FDG injection of 3.70 MBq/kg,Sharp IR+time of flight + VUE Point HD technology were used for 1.5 min/bed in PET; CT of spiral scan was performed under 120 kV using automatic exposure control technology (30-210 mA,noise index 25).Model and patients whole body CT images were reconstructed with conventional and 40％ ASiR methods respectively,and the CT attenuation value and noise index were measured.Results Research of model and clinical showed that standard deviation of ASiR method in model CT was 33.0％ lower than the conventional CT reconstruction method (t =27.76,P＜0.01),standard deviation of CT in normal tissues (brain,lung,mediastinum,liver and vertebral body)and lesions (brain,lung,mediastinum,liver and vertebral body) reduced by 21.08％ (t =23.35,P＜0.01) and 24.43％ (t =16.15,P＜0.01) respectively,especially for normal liver tissue and liver lesions,standard deviations of CT were reduced by 51.33％ (t=34.21,P＜0.0)and 49.54％ (t=15.21,P＜0.01) respectively.Conclusion ASiR reconstruction method was significantly reduced the noise of low dose CT image and improved the quality of CT image in whole body PET/CT,which seems more suitable for quantitative analysis and clinical applications.