迭代算法对超低剂量CT肺部扫描图像质量影响的体模研究  

Phantom study of the influence of iterative algorithm on image quality in ultra-low-dose CT scan of lung

作　　者：何长久 周鹏 胡仕北 青浩渺 董晓蕾 李海烈 李德珊 龙海飘 He Changjiu;Zhou Peng;Hu Shibei;Qing Haomiao;Dong Xiaolei;Li Hailie;Li Deshan;Long Haipiao(Department of Radiology,Sichuan Cancer Hospital & Institute,Sichuan Cancer Center,School of Medicine, University of Electronic Science and Technology of China,Chengdu 610041,China)

机构地区：[1]四川省肿瘤医院·研究所四川省癌症防治中心电子科技大学医学院放射科,成都610041

出　　处：《中华放射医学与防护杂志》2019年第2期145-149,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：四川省科技计划项目(2017JY0080、2018SZ0183).

摘　　要：目的探讨迭代算法对超低剂量CT肺部扫描图像质量的影响。方法采用不同方案对胸部仿真体模行CT扫描。超低剂量方案:管电压分为80和100kV组,每组分别采用10、15、20、25、30mAs扫描。常规低剂量方案:120kV、30mAs。各方案均采用滤波反投影法(FBP组)和迭代算法重建(迭代组)。比较各方案的肺组织噪声和有效剂量(E)。结果管电流和管电压一定时,迭代组的肺组织噪声均低于FBP组,差异均有统计学意义(t=1.102~8.070,P<0.05)。管电流一定时,80kV时FBP组的肺组织噪声均高于100kV时FBP组,80kV时迭代组的肺组织噪声均低于100kV时FBP组,差异均有统计学意义(t=-8.639~7.841,P<0.05)。与常规低剂量方案FBP组相比,各超低剂量方案FBP组的肺组织噪声明显增加,80kV时10、15、20mAs迭代组的肺组织噪声明显增加,100kV时15、20、25、30mAs迭代组的肺组织噪声明显降低,差异均有统计学意义(t=-8.140~23.028,P<0.05)。80kV时25、30mAs和100kV时10mAs迭代组的肺组织噪声与常规低剂量方案FBP组比较,差异均无统计学意义(P>0.05)。80kV时25、30mAs和100kV时10、15、20、25、30mAs的E较常规低剂量组分别降低了75.9%、71.0%、79.8%、70.4%、60.3%、50.2%、40.0%。结论超低剂量方案(100kV、10mAs)迭代算法组的图像质量与常规低剂量方案FBP组相当,且辐射剂量明显降低。Objective To explore the influence of iterative algorithm on image quality in ultra-low-dose CT scan of lung. Methods The thoracic model was scanned using different parameter combinations. The tube voltage was chose with 80, 100 kV in ultra-low dose group and the mAs was selected by 10, 15, 20, 25 and 30 mAs. The control group selected the parameters of 120 kV, 30 mAs. All the images were reconstructed with filtered back projection (FBP group) and iterative algorithm (IR group). The image noise and effective dose (E) were compared. Results When tube current and voltage were constant, the image noise of IR group was lower than that of FBP group, and the difference was statistically significant (t=1.102–8.070, P<0.05). When the tube current was constant, the image noise of the 80 kV with FBP group was higher than that of 100 kV with FBP group, and the image noise of the 80 kV with IR group was lower than the 100 kV with FBP group(t=-8.639-7.841, P<0.05). Compared with the conventional low-dose with FBP group, the image noise of each ultra-low-dose with FBP group was significantly increased, and the image noise of (80 kV, 10 mAs), (80 kV, 15 mAs), (80 kV, 20 mAs) with IR group was significantly increased, and the image noise of (100 kV, 15 mAs), (100 kV, 20 mAs), (100 kV, 25 mAs), (100 kV, 30 mAs) with IR group was significantly reduced (t=-8.140-23.028, P<0.05). There was no significant difference in image noise between the groups of (80 kV, 25 mAs), (80 kV, 30 mAs), (100 kV, 10 mAs) with IR and the group of conventional low dose with FBP (P>0.05). Compared with the conventional low dose group, the E of the groups of (80 kV, 25 mAs), (80 kV, 30 mAs), (100 kV, 10 mAs), (100 kV, 15 mAs), (100 kV, 20 mAs), (100 kV, 25 mAs), (100 kV, 30 mAs) was decreased by 75.9%, 71.0%, 79.8%, 70.4%, 60.3%, 50.2%, 40.0%, respectively. Conclusions The image quality of the ultra-low dose protocol (100 kV, 10mAs) with iterative algorithm is similar to that of the conventional low dose with FBP group, and the radiation dose could be si

关 键 词：体层摄影术 肺 辐射剂量 图像质量 迭代算法 

分 类 号：R734.2[医药卫生—肿瘤] R730.44[医药卫生—临床医学]