自适应统计迭代重建技术在PET/CT全身扫描中的应用  

Adaptive statistical iterative reconstruction technology in the application of PET/CT whole body scans

作　　者：辛军[1] 赵周社[1] 李红[1] 陆喆[1] 吴文凯[1] 郭启勇[1] 

机构地区：[1]中国医科大学附属盛京医院放射科,沈阳110004

出　　处：《国际放射医学核医学杂志》2013年第5期279-282,共4页International Journal of Radiation Medicine and Nuclear Medicine

摘　　要：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.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.

关 键 词：肿瘤 正电子发射断层显像术 体层摄影术 X线计算机 自适应统计迭代重建 

分 类 号：R817[医药卫生—影像医学与核医学] R814.42[医药卫生—放射医学]