多排螺旋CT辐射剂量表征量校正方法初探  

A method to correct the characterizations of MDCT

作　　者：庄静文[1] 白玫[1] 郑均正[1] 

机构地区：[1]首都医科大学宣武医院医学工程处,北京100053

出　　处：《中国医学装备》2015年第9期5-8,共4页China Medical Equipment

基　　金：国家自然科学基金(81372923)"宽探测器螺旋CT所致辐射剂量评价方法研究";国家科技支撑计划(2011BAI02B02)"医用光学与放射影像设备计量标准及溯源体系研究"

摘　　要：目的:探讨多排螺旋CT检查所致辐射剂量的准确值与常用的CT辐射剂量表征量以及扫描参数之间的关系,以校正目前常用的CT辐射剂量表征量。方法:使用长杆电离室测量Siemens SOMATOM Definition Flash CT不同准值宽度、螺距以及管电压下直径16 cm体模内剂量分布曲线,并使用SPSS软件进行分析。结果:测量得到的CTDIw和加权CTDI∞在0.05水平上有显著性差异,经校正后所得的加权CTDI∞与测量所得加权CTDI∞在0.05水平上无显著性差异。结论:多排螺旋CT目前常用的CT辐射剂量表征量缺乏准确性。经验证,根据实验结果得到的校正方法基本准确,可以对西门子Definition Flash CT的CTDIw进行校正,使用其他多排螺旋CT扫描其他部位时CTDIw的校正有待进一步研究。Objective：To correct the characterizations of MDCT radiation dose by exploring the relationship between CTDIw,∞ and CTDIw.Methods： CTDI100 and CTDI∞ were measured under the conditions of different collimations, pitches and tube voltages of Siemens Definition Flash CT, and CTDIw and CTDIw,∞ were calculated.Results： There were significant differences between CTDIw and CTDIw,∞ which were measured at 0.05 level. And there were no significant differences between CTDIw,∞ after corrected and CTDIw,∞ which were measured at 0.05 level.Conclusion：The characterizations of MDCT which were commonly used were not accurate enough. The result after correction were very closed to the real CTDIw,∞. This showed that the method to correct CTDIw of Siemens Definition Flash CT was mostly accurate. And methods to correct CTDIw of other MDCT needed to be further studied.

关 键 词：多排螺旋CT CT剂量指数 校正方法 

分 类 号：R144.1[医药卫生—公共卫生与预防医学]