定量CT和双回波MRI评价骨质疏松  

Quantitative computed tomography and in-phase and out-phase MRI in evaluation of osteoporosis

作　　者：张灵艳[1] 李绍林[1] 郝帅[1] 严杰文[1] 

机构地区：[1]南方医科大学第三附属医院(广东省骨科研究院)医学影像科,广东广州510630

出　　处：《中国医学影像技术》2015年第10期1466-1469,共4页Chinese Journal of Medical Imaging Technology

基　　金：南方医科大学第三附属医院院长基金(B201012)

摘　　要：目的探讨定量CT(QCT)和双回波MR成像评价骨质疏松的价值。方法对74名志愿者行前瞻性队列研究,分别采用双能X线骨密度测量仪(DXA)和QCT检测腰椎骨密度,MR扫描仪及后处理软件检测腰椎椎体内骨髓脂肪组织。根据腰椎DXA结果分为骨量正常组、低骨量组和骨质疏松组,采用单因素方差分析比较3组间信号强度比值(SIR)的差异;采用Pearson相关分析分别检验双回波MRI技术所测SIR与DXA的T值及QCT所测骨量的相关性;采用ROC曲线分析SIR值对骨质疏松的诊断效能。结果骨量正常组SIR值0.41±0.11,低骨量组SIR值0.55±0.12,骨质疏松组SIR值0.62±0.15,三组间差异有统计学意义(F=18.5,P=0.002),骨量正常组与骨质疏松组间、骨量正常组与低骨量组间SIR差异有统计学意义(P均<0.01),而低骨量组与骨质疏松组间SIR差异无统计学意义(P=0.194),QCT所测骨量与DXA所测T值呈正相关(r=0.675,P<0.01),SIR值与T值呈负相关(r=-0.587,P<0.01)。SIR值与QCT所测骨量呈负相关关系(r=-0.599,P<0.001)。采用SIR评价骨质疏松的ROC分析显示,SIR=0.54时,ROC曲线下面积最大,为0.833,诊断的敏感度为83.3%,特异度为75.7%。结论 QCT可直接精确测量骨质密度;双回波MRI技术可通过检测骨髓脂肪组织间接反映骨代谢情况。Objective To explore the value of quantitative computed tomography（QCT）and in-phase and out-phase MRI in evaluation of osteoporosis.Methods A prospective cohort study was performed on 74 volunteers.Dual-energy X-ray absorptiometry（DXA）and QCT were applied to measure lumber bone density.MRI and post-processing software were applied to measure lumbar bone marrow adipose tissue.According to the results of lumbar DXA,volunteers were divided into normal bone mass group,low bone mass group and osteoporosis group.One way ANOVA was applied to compare the signal intensity ratio（SIR）value among three groups.Pearsoncorrelation analysis was applied to measure the correlation among SIR measured by in-phase and out-phase MRI,T value measured by DXA,and bone mass measured by QCT.ROC curve was applied to analyze the diagnostic efficacy value.Results The SIR value of normal bone mass group,low bone mass group and osteoporosis group were 0.41±0.11,0.55±0.12,and 0.62±0.15,respectively,and the differences among the three groups were statistically significant（F=18.5,P=0.002）.The differences between normal bone mass group and osteoporosis group was of statistical significance（P〈0.01）,as well as the differences between normal bone mass group and low bone mass group.However,the difference between low bone mass group and osteoporosis group was of no statistical importance（P=0.194）.Bone mass measured by QCT was positively correlated with T value measured by DXA（r=0.675,P〈0.01）.SIR was negatively correlated with T value（r=-0.587,P〈0.01）.SIR was negatively correlated with bone mass detected by QCT（r=-0.599,P〈0.001）.When SIR=0.54,the largest area under the ROC curve was 0.833,with the sensitivity of 83.3% and specificity of 75.7%.Conclusion QCT can be applied to measure bone density directly and accurately.By detecting bone marrow adipose tissue,in-phase and out-phase MRI can indirectly reflect the bone metabolism.

关 键 词：磁共振成像 体层摄影术 X线计算机 骨质疏松 骨髓脂肪 

分 类 号：R445[医药卫生—影像医学与核医学] R714.257[医药卫生—诊断学]