IDEAL-IQ技术对骨质疏松与转移瘤所致椎体压缩骨折的诊断价值

目的探讨磁共振多点非对称回波采集与迭代最小二乘法水脂分离技术(iterative decomposition of water and fat with echo asymmetry and the least squares estimation quantification sequence,IDEAL-IQ)椎体骨髓脂肪含量测定对于鉴别骨质疏松与转移瘤所致椎体压缩骨折的可行性。方法通过IDEAL-IQ序列对骨质疏松和转移瘤所致椎体压缩骨折椎体病变区及正常对照椎体的骨髓脂肪含量FF值、R2*值进行定量测定;并计算其椎体骨髓脂肪含量FF比值。运用Mann-Whitney U检验统计分析骨质疏松和转移瘤所致椎体压缩骨折椎体病变区FF值、R2*值及FF比值之间的统计学差异,受试者工作特征(receiver operator characteristic,ROC)曲线分析判断各参数诊断效能。结果骨质疏松与转移瘤所致椎体压缩骨折椎体病变区骨髓脂肪含量FF值、R2*及FF比值间差异均有统计学意义(P<0.05)。ROC曲线分析FF值对上述两种病因鉴别诊断的临界值为10.58%。FF值、R2*值、FF比值鉴别骨质疏松所致椎体压缩骨折及转移瘤所致椎体压缩骨折的ROC曲线下面积分别为0.967、0.715、0.921。结论磁共振IDEAL-IQ椎体骨髓脂肪含量的测定对骨质疏松与转移瘤所致椎体压缩骨折的鉴别诊断具有一定的可行性和临床价值。

The diagnostic value of IDEAL-IQ for vertebral compression fractures caused by osteoporosis and tumor metastasis

Objective To investigate the feasibility of iterative decomposition of water and fat with echo asymmetry and the least squares estimation quantification sequence(IDEAL-IQ)in the quantitative detection of the bone marrow fat content in vertebral compression fractures caused by osteoporosis and tumor metastasis.Methods On the acquired IDEAL-IQ sequence,the FF and R2*values in the lesions of vertebral compression fractures were independently measured in all patients.In addition,FF ratio,defined as FF value of the lesion/FF value in the normal vertebral bone marrow,was calculated in each patient.Mann-Whitney U test was used to determine the differences of FF,FF ratio,and R2*between the parameters of osteoporosis and metastasis.In addition,the receiver operating characteristic curve(ROC)analysis was applied to estimate the diagnostic efficacy of FF,FF ratio,and R2*in vertebral compression fractures.Results Significant lower FF values,R2*values,and FF ratios of bone marrow fat content were found(P<0.05)in the metastasis caused vertebral lesions than the osteoporosis caused acute compression fractures.All FF cut-off values of acute compression fractures for diagnostic performance on ROC analysis revealed that a cut-off value of 10.58%was optimal to differentiate between metastasis and osteoporosis.High AUC values of FF,R2*,and FF ratio were shown,indicating a robust differentiation of metastatic tumor compression fractures from osteoporosis acute compression fractures(0.967,0.715,and 0.921).Conclusion IDEAL-IQ has revealed its feasibility and clinical values in distinguishing the vertebral compression fractures caused by osteoporosis or by tumor metastasis.