64层螺旋CT胸部低剂量扫描方案优选的多中心研究  

The optimization of low-dose scanning protocols of 64-slice spiral CT in the adult chest： a multicenter study

作　　者：唐威[1] 黄遥[1] 吴宁[1] 蔡强[1] 陈星[1] 王建卫[1] 赵世俊[1] 黎庶 初金刚 李海波[3] 张滨[3] 肖喜刚[4] 谢德轩[4] 杨贤卫[5] 郑芸[5] 谢元亮[6] 金朝林[6] 肖香佐[7] 姜健[7] 

机构地区：[1]中国医学科学院北京协和医学院肿瘤医院影像诊断科,100021 [2]科大学附属第一医院放射科 [3]北京大学首钢医院放射科 [4]哈尔滨医科大学附属第一医院CT室 [5]广州中医药大学附属第一医院放射科 [6]武汉市中心医院影像科 [7]南昌大学第一临床学院放射科

出　　处：《中华放射学杂志》2011年第2期142-148,共7页Chinese Journal of Radiology

基　　金：基金项目：国家“十一五”科技支撑项目（2006BAl01A13,2007BAl05805）;首都医学发展科研基金项目（2005-1039）

摘　　要：目的比较自动曝光控制技术（AEC）与管电流恒定技术（CCC）2种不同低剂量MSCT扫描方案对胸部CT图像质量的影响，探讨更加合理的肺低剂量扫描参数方案。方法采用前瞻性多中心研究方法，研究对象为7所医院就诊的280例行胸部低剂量MSCT检查的受检者，设定管电流（mA）为研究变量，方法一为AEC技术，下设噪声标准差值（sD）为25（A1）及30（A2）各1组，并设定管电流上限为80mA，下限为10mA；方法二为ccc技术，下设40mA（c1）及50mA（c2）各1组；共4组，采用同一机型64层MSCT行胸部低剂量扫描。2名放射科医师应用双盲法阅片，比较2种不同扫描技术的曝光剂量、sD值，横断面、MPR的图像质量以及体质量指数（BMI）对图像质量的影响。曝光剂量及SD比较行方差分析及t检验；图像质量比较行Mann—Whitney检验；医师对图像诊断一致性检验行Kappa分析。结果剂量长度乘积（DLP）AEC组较CCC组明显降低[（82．62±40．31）和（110．81±18．21）mGy·cm，F=56．88，P〈0．01]。AEC技术中A2组DLP较A1组低[（72．77±36．68）和（92．46-I-41．61）mGy·cm]，差异无统计学意义（t=0．82，P〉0．05）。前者sD值在肺窗[（41．50±9．58）和（40．86±7．03）HU]及纵隔窗[（41．19±7．83）和（40．92±9．89）HU]均略高于后者，差异无统计学意义（F％自=0．835、1．910，P值均〉0．05）。横断面图像质量AEC组肺窗得分除右下肺静脉水平[（4．92±0．25）和（4．93±0．17）分]、[左膈顶上缘水平（4．91±0．27）和（4．93±0．22）分]较CCC组略低外，AEC组得分均较CCC组略高[头臂静脉上缘（4．49±0．56）和（4．38±0．64）分；主动脉弓上缘（4．86±0．23）和（4．81±0．32）分；右肺上叶支气管开口（4．87±0．27）和（4．84±0．22）分；右肺中叶支气管开口（4．90±0．25）和（4．88±0．21）分]，差异无统计学意义（F：0Objective To compare the image quality of chest low dose CT （LDCT） using automatic exposure control （AEC） and constant current control （CCC） and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 （ A1 ） and 30 （ A2 ） respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA （ C1 ） and 50 mA （C2） respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols. The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically. Differences of radiation dose and noise among groups were determined with variance analysis and t test, image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [ （82. 62 ±40. 31） vs （ 110. 81 ± 18.21）mGy . cm （F =56. 88 ,P 〈 0.01 ）], whereas no significant difference was observed between group A2 and group A1 [group A1 -- （92.46 ±41.61） mGy . cm vs group A2 -- （72.77 ±36.68） mGy .cm, t =0.82,P〉 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window（41.50 ±9. 58 vs 40. 86 ± 7.03 ） and mediastinum window （ 41.19 ± 7. 83 vs 40. 92 ± 9. 89 ） , but there was no significant difference（ Flu.g = 0. 835, P = 0. 476, Fmediasti . 1. 910, P = 0. 128 ）. The quality score of axial image in AEC group was higher than that in CCC group （ superior margin of the braehioeephalic vein level ： 4.49 ± 0. 56 vs 4. 38 ± 0. 64, superior margin of the aortic arch： 4. 86 ± 0. 23 vs 4. 81 ± 0. 32, the fight superior lobar bronchus Level ： 4.87 ± 0. 27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level ： 4. 90 ± 0. 25 vs 4. 88 ±0. 21 �

关 键 词：胸部 体层摄影术 X线计算机 诊断技术和方法 辐射剂量 

分 类 号：R816.4[医药卫生—放射医学]