不同管电压对定量CT骨密度测量结果的影响  

Effect of different tube voltage on result of bone mineral density measured by quantitative computed tomography

作　　者：王予生[1] 过哲[1] 赵海竹[1] 刘庆华[1] 白荣杰[1] 程晓光[1] 

机构地区：[1]北京积水潭医院放射科,北京100035

出　　处：《中国医学影像技术》2015年第10期1475-1478,共4页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金(81071131);首都卫生发展科研专项自主创新项目(2014-2-1122)

摘　　要：目的探讨不同管电压对定量CT(QCT)骨密度(BMD)测量结果的影响。方法采用Toshiba Aquilion 64排CT机,对欧洲标准脊柱体模和QCT校准体模行CT扫描,根据不同管电压分为80kV组、100kV组、120kV组、135kV组。每组除电压不同外,其余扫描参数相同,重建标准体模影像,并进行BMD测量。结果 4组标准体模平均BMD值差异有统计学意义(F=3944.32,P<0.05);80kV组、100kV组、135 kV组平均BMD值与标准体模BMD真值(116.67mg/cm3)差异有统计学意义(P均<0.05)。80kV组、100kV组、120kV组、135kV组BMD测量值减真值的绝对值分别为(57.22±1.80)mg/cm3、(22.82±0.65)mg/cm3、(0.08±0.27)mg/cm3、(15.94±2.52)mg/cm3。管电压与平均BMD呈负相关(r=-0.993,P<0.05)。结论不同管电压对QCT BMD的测量结果有影响。采用QCT测量BMD时,建议将扫描协议中管电压固定为120kV。Objective To assess the effect of different tube voltage on the quantitative computed tomography（QCT）bone mineral density（BMD）measurement.Methods European Spine Phantom（ESP）and QCT calibration phantom were scanned with a 64-row Toshiba CT scanner under 4different tube voltages 80 kV,100kV,120 kV,and 135 kV group respectively.In addition to the voltage,the other scanning parameters were the same in different groups.Standard phantom images were reconstructed,and the BMD was measured.Results There were statistically significant differences among the 4groups of standard phantom mean BMD values（F=3944.32,P〈0.05）.The BMD of 80 kV group,100 kV group,135 kV group were statistically significant compared with that of the standard phantom（BMD=116.67mg/cm^3,all P〈0.05）.The absolute value of BMD measured in 80 kV,100kV,120 kV,135kV minus the true value were（57.22±1.80）mg/cm^3,（22.82±0.65）mg/cm^3,（0.08±0.27）mg/cm^3,（15.94±2.52）mg/cm^3.Tube voltage was negatively correlated with BMD（r=-0.993,P〈0.05）.Conclusion Different tube voltage can affect BMD measurement of QCT.Tube voltage in QCT scan protocol should be fixed at 120 kV to ensure accurate measurement of QCT.

关 键 词：管电压 骨密度 体层摄影术 X线计算机 

分 类 号：R814.42[医药卫生—影像医学与核医学]