磁共振T1ρ和T2-mapping定量技术对股骨头坏死软骨变性的对照研究

Quantitative MRI techniques of T_1ρ and T_2-mapping in detecting cartilage injury following osteonecrosis of femoral head:a correlative study

目的:分析T_1ρ和T_2-mapping定量MRI技术在股骨头坏死软骨变性中的诊断价值。方法:对24例健康志愿者(对照组)及47例股骨头坏死(ARCOⅠ~Ⅲ期)初治患者行MRI扫描,扫描序列包括常规MRI、多回波回复梯度回波(MERGE)、T_1ρ及T_2-mapping。测量定量参数T_1ρ及T_2-mapping值,并采用Pearson相关分析评估两者之间的相关性,采用受试者工作特征曲线(ROC)对两者的诊断效能进行评价。结果:股骨头坏死组的T_1ρ和T_2-mapping值明显高于对照组,差异有统计学意义(t=-4.51、-3.77,P<0.01)。T_1ρ与T_2-mapping值呈正相关关系(r=0.381,P<0.01)。T_1ρ的ROC下最大面积为0.822,相应的敏感度和特异度分别为72.34%和70.83%,特异度明显高于T_2-mapping(58.33%)。结论:磁共振T_1ρ及T_2-mapping成像技术均可用于股骨头坏死患者软骨变性的定量诊断,T_1ρ的诊断价值稍高于T_2-mapping。

Objectives：To study the diagnostic value of quantitative MRI techniques of T1 ρ and T2-mapping in detecting cartilage damage of femoral head osteonecrosis. Methods： Twenty-four healthy volunteers （control group） and forty- seven newly diagnosed patients with osteonecrosis of femoral head （ARCO stageⅠ-Ⅲ） underwent conventional, MERGE,T1 ρ and T2-mapping MRI examinations. The quantitative parameters values of T1ρ and T2 mapping were meas- ured, and the correlation between T1ρ and T2-mapping was analyzed by Pearson correlation analysis,and their diagnosis effi- cacy was evaluated by receiver operating characteristic curve （ROC）. Results：The T1ρ and T2 mapping values of the patient group were higher than those of control group with statistically significant difference （P= 4.51 and -3.77, respectively; P〈0.01）. The values of T19 showed positive correlation with T2 mapping （r= 0. 381, P〈0.01）. The maximum area under the ROC of T1ρ was 0. 822, and the corresponding sensitivity and specificity were 72.34 % and 70.83 % respectively, its specificity was higher than that of T2-mapping （58.33 X）. Conclusion： Both T1 9 and T2-mapping MRI techniques can be used for quantitative diagnosis of the cartilage injury in patients with of femoral head osteonecrosis,the diagnostic performance of T1ρ is better than T2-mapping.