磁共振脂肪定量技术IDEAL-IQ评价腰椎骨质疏松严重程度的价值

Value of MR IDEAL-IQ Sequence in Evaluating the Severity of Lum bar Osteoporosis

目的 探讨基于MRI迭代最小二乘法水脂分离定量技术(IDEAL-IQ)的椎体骨髓脂肪分数(FF)值在评估腰椎骨质疏松严重程度中的价值。方法 收集88例同时接受双能X线骨密度测量(DXA)和腰椎IDEAL-IQ序列检查的患者,根据DXA结果分为正常骨量组(36例)、低骨量组(23例)和骨质疏松组(29例),并在IDEAL-IQ序列脂肪分数图中测量椎体的脂肪分数;应用单因素方差分析比较3组椎体的FF值,ROC曲线评估诊断效能;FF值与年龄、身高、体重、BMI指数以及BMD值进行Pearson相关分析。结果 正常骨量组、低骨量组、骨质疏松组FF值分别为(38.84±6.75)%、(51.96±7.65)%、(58.39±12.81)%,总体及组间比较差异显著(P<0.05);FF值识别正常组、低骨量组的AUC为0.797,以46.85%为阈值,敏感度、特异度分别为73.91%、80.56%;FF值识低骨量组、骨质疏松组的AUC为0.691,以57.12%为阈值,敏感度、特异度分别为79.31%、69.57%。FF值与年龄呈正相关(P<0.001,r=0.6059);FF与身高(P<0.001,r=-0.3783)、体重(P<0.001,r=-0.4686)、BMI(P<0.001,r=-0.3649)、BMD(p=0.01,r=-0.2738)呈负相关;与性别无明确相关性。结论 IDEAL-IQ能够精准量化椎体的骨髓脂肪含量,对评估骨质疏松症严重程度有一定价值,有助于从骨质量层面反映骨质疏松状态。

Objective To explore the application value of vertebral bone marrow fat fraction(FF)measured by IDEALIQ in evaluating the severity of lumbar osteoporosis.Methods Eighty-eight patients who underwent both dual-energy X-ray bone densitometry(DXA)and IDEAL-IQ sequence examination of the lumbar spine were collected and divided into normal bone mass group(36 patients),low bone mass group(23 patients)and osteoporosis group(29 patients)according to the DXA results,and the fat fraction of vertebrae was measured in the IDEAL-IQ sequence fat fraction map;one-way ANOVA was applied to compare the FF values of vertebrae in the three groups.The diagnostic efficacy was assessed by ROC curves;Pearson correlation analysis was performed between FF values and age,height,weight,BMI index and BMD values.Results The FF values were(38.84±6.75)%,(51.96±7.65)%,and(58.39±12.81)%in the normal bone mass group,low bone mass group,and osteoporosis group respectively.The differences were statistically significant overall and between-group(P<0.05).The AUC of FF value for distinguishing normal group and low bone mass group was 0.797,with 46.85%as cut-off value,the sensitivity and specificity were 73.91%and 80.56%respectively.The AUC of FF value for distinguishing low bone mass group and osteoporosis group was 0.691,with 57.12%as cut-off value,the sensitivity and specificity were 79.31%and 69.57%respectively.The FF value is positively correlated with age(P<0.001,r=0.6059);FF was negatively correlated with height(P<0.001,r=-0.3783),weight(P<0.001,r=-0.4686),BMI(P<0.001,r=-0.3649),BMD(P=0.01,r=-0.2738);there is no correlation between FF and gender.Conclusion The FF value of the MRI IDEAL-IQ sequence can reflect the fat content of the bone marrow of the vertebral spine,which has a certain value in evaluating the severity of osteoporosis,and helps to reflect the osteoporosis status from the level of bone quality.