Karl 3D 迭代重建技术对胸部低剂量 CT 图像质量的影响  

Effect of Karl 3D iterative reconstruction technique on the image quality of the chest low-dose CT

作　　者：朱莉 周慧 

机构地区：[1]上海市嘉定区中心医院影像科,上海201800

出　　处：《实用放射学杂志》2017年第2期280-282,共3页Journal of Practical Radiology

摘　　要：目的：探讨 Karl 3D 迭代重建技术在胸部低剂量 CT 检查中应用的可行性。方法将本院做健康体检,体质量指数（BMI）为中等的120例胸部平扫人员随机平均分成2组。A 组60例为对照组,采用传统120 kV,150 mAs 的常规剂量扫描和滤波反投影算法（FBP）重建图像；B 组60例为研究组,使用120 kV,80 mAs 低剂量扫描,分别采用 FBP 和 Karl 3D 5级迭代重建算法重建图像。由2名主治医师采用5分制双盲阅片的方式对图像质量做出主观评价,并用 Kappa 检验评价观察者间的一致性；各组图像主支气管分叉平面,胸降主动脉区域画感兴趣区（ROI）,测量其 CT 值及标准差（SD）,以 SD 对图像的噪声做出客观评价；并且比较2组研究对象的 CT 剂量指数（CTDIvol）、剂量长度乘积（DLP）,并估算有效剂量（ED）,通过统计软件分析其结果。结果2名医师对图像质量评分的一致性较好（Kappa =0.890）。B 组低剂量 Karl 3D 5级迭代重建算法重建的图像与 A 组常规剂量图像质量相当,两者差异无统计学意义（P =0.09）；并且辐射剂量明显下降（达47.47%）,差异有统计学意义（P 〈0.01）。B 组使用 Karl 3D 5级迭代重建的图像较 FBP 重建的图像噪声明显下降,图像质量明显提高,两者差别有统计学意义（P 〈0.01）。结论Karl 3D 迭代重建技术完全可以运用在胸部低剂量 CT 检查中。Objective To investigate the feasibility of Karl 3D iterative reconstruction technique in the chest low-dose CT examination. Methods 120 cases made health examination in our hospital and with the moderate body mass index （BMI）were randomly divided into 2 groups.Group A of 60 cases performed chest CT by using 120 kV,150 mAs conventional dose scanning and filtered back projection （FBP）algorithm image reconstruction.Group B of 60 cases performed chest CT by using 120 kV,80 mAs low-dose scanning and FBP and Karl 3D 5 level iterative reconstruction algorithm image reconstruction.Two attending doctors using a 5-point,double-blind manner to evaluate the image quality.The interobserver agreement was analyzed with the Kappa test.The CT value and the standard deviation （SD）of the two groups were measured on the region of interest （ROI）in the main bronchus and descending thoracic aorta.The CT dose index （CTDIvol）,dose length product （DLP）,and the effective dose （ED）were compared between the two groups using by SPSS17.0 statistical software.Results There was a good agreement for the image quality among the two physicians （Kappa =0.890）.The image quality of Group B using Karl 3D 5 level iterative reconstruction algorithm was similar with that of Group A （P =0.09）,and the radiation dose significantly decreased 4 7 .4 7 % （P 〈 0 .0 1 ）.Com pared to FBP image reconstruction,the noise of Group B using Karl-level 3 D 5 iterative reconstruction was significantly decreased,and the image quality was significantly improved （P 〈0.01）.Conclusion Karl 3D iterative reconstruction technique can be used in chest low-dose CT examination.

关 键 词：计算机体层成像 低剂量 滤波反投影 迭代重建算法 

分 类 号：R814.42[医药卫生—影像医学与核医学] R816.4[医药卫生—放射医学]