mDIXON-Quant技术评估中老年女性骨质量的临床研究

Clinical study of mDIXON-Quant technique in evaluating the bone quality of middle-aged and elderly women

目的探讨中老年女性腰椎骨髓脂肪分数(fat fraction,FF)和T2*值与骨密度(bone mineral density,BMD)的关联性及mDIXON-Quant技术对骨量下降的诊断效能。方法招募中老年女性健康志愿者共126名,采用双能X线吸收测量仪(dual-energy X-ray absorptiometry,DXA)、定量CT(quantitative CT,QCT)测量腰椎椎体BMD,运用mDIXON-Quant技术测量腰椎FF和T2*值。分别根据DXA和QCT测量的BMD将受试者分为骨量正常组、骨量减少组、骨质疏松(OP)组。分析三组间FF、T2*值的差异并对FF、T2*值与BMD(DXA/QCT)进行相关分析,绘制受试者工作特征曲线(receiver operating characteristic curve,ROC),分析FF、T2*值评估低骨量的诊断效能。结果以DXA为标准分组:骨量正常组与OP组FF和T2*值、骨量减少组与OP组FF差异有统计学意义(P<0.05),FF与BMD呈负相关(r=-0.365,P=0.000;校正年龄因素后r=-0.205,P=0.022),T2*值与BMD呈负相关(r=-0.221,P=0.013;校正年龄因素后r=-0.205,P=0.022),FF、T2*值、FF+T2*值评估低骨量的曲线下面积(area under curve,AUC)分别为0.625、0.631、0.657。以QCT为标准分组:骨量正常组与骨量减少组、骨量正常组与OP组FF及T2*值差异有统计学意义(P<0.05),FF与BMD呈负相关(r=-0.687,P=0.000;校正年龄因素后r=-0.497,P=0.000),T2*值与BMD呈负相关(r=-0.360,P=0.000;校正年龄因素后r=-0.393,P=0.000),FF、T2*值、FF+T2*值评估低骨量的AUC分别为0.799、0.700、0.813。结论mDIXON-Quant技术能够同时定量FF与T2*值,其评估以QCT为标准的低骨量的效能优于DXA,联合应用QCT与mDIXON-Quant技术能更准确评估中老年女性骨质量。

Objective To investigate the correlations between fat fraction(FF),T2*value and bone mineral density(BMD)and the diagnostic efficacy of mDIXON-Quant technique for bone mass loss in middle-aged and elderly women.Methods A total of 126 middle-aged and elderly female health volunteers were recruited,used dual-energy X-ray absorptiometry(DXA),quantitative CT(QCT)to measure the lumbar vertebral body BMD,used the mDIXON-Quant technique to measure the FF and T2*value of the lumbar spine.According to the BMD measured by DXA and QCT,the subjects were divided into the normal group,the osteopenia group,and the osteoporosis(OP)group.Analyzed the differences between FF and T2*value among the three groups and analyzed the correlations between FF,T2*value and BMD(DXA/QCT),drew the receiver operating characteristic curve(ROC),and analyzed the diagnostic efficacy of FF and T2*value to predict low bone mass.Results Group by DXA as standard:the differences of FF and T2*value between the normal group and the OP group,the difference of FF between the osteopenia group and the OP group were statistically significant(P<0.05),FF was negatively correlated with BMD(r=-0.365,P=0.000;after adjusting for age factors,r=-0.205,P=0.022),T2*value was negatively correlated with BMD(r=-0.221,P=0.013;after adjusting for age factors,r=-0.205,P=0.022),The area under curve(AUC)of FF,T2*value and FF+T2*value to predict low bone mass were 0.625,0.631 and 0.657,respectively.Group by QCT as standard:the differences of FF and T2*value between the normal group and the osteopenia group,the differences of FF and T2*value between the normal group and OP group were statistically significant(P<0.05),FF was negatively correlated with BMD(r=-0.687,P=0.000;after adjusting for age factor r=-0.497,P=0.000),T2*value was negatively correlated with BMD(r=-0.360,P=0.000;after adjusting for age group r=-0.393,P=0.000),the AUC of FF,T2*value and FF+T2*value to predict low bone mass were 0.799,0.700 and 0.813 respectively.Conclusion The mDIXON-Quant technique can simultaneously quantify the FF and T2*value,and its’performance in predicting low bone mass of QCT standard is better than that of DXA standard.The combined application of QCT and mDIXON-Quant technique can more accurately evaluate the bone quality of middle-aged and old women.