基于3D黑骨序列测量Legg-Calvé-Perthes病股骨头突出指数并评估其Herring分型

3D black bone sequence for measuring femoral head extrusion index and evaluating Herring classification of Legg-Calvé-Perthes disease

目的观察基于3D黑骨序列测量Legg-Calvé-Perthes病(LCPD)股骨头突出指数并评估其Herring分型的价值。方法回顾性分析38例单侧LCPD患儿髋关节MRI,分别比较冠状位3D黑骨序列类X线图及冠状位脂肪抑制T2WI与髋关节正位X线片所测患/健侧股骨头突出指数;以髋关节X线片为金标准,绘制受试者工作特征曲线,计算曲线下面积(AUC),分析3D黑骨序列及脂肪抑制T2WI评估LCPD Herring分型的效能,并以DeLong检验进行比较。结果基于X线片及3D黑骨序列类X线图测得LCPD健侧股骨头突出指数分别为(11.31±6.16)%及(11.47±5.83)%,差异无统计学意义(P>0.05);患侧股骨头突出指数分别为(22.45±9.21)%及(22.82±7.92)%,差异无统计学意义(P>0.05)且均显著高于健侧(P均<0.001)。基于脂肪抑制T2WI测得LCPD患侧及健侧股骨头突出指数分别为(28.01±2.01)%及(27.25±1.92)%,差异无统计意义(P>0.05)且分别高于基于X线片所获患侧与健侧股骨头突出指数(P均<0.001)。3D黑骨序列及脂肪抑制T2WI评估LCPD Herring分型的AUC为0.750~0.938及0.625~0.705。3D黑骨序列评估LCPD Herring B型的AUC高于脂肪抑制T2WI(P<0.05),二者评估LCPD其他Herring分型的AUC差异均无统计学意义(P均>0.05)。结论3D黑骨序列可用于测量LCPD股骨头突出指数并评估其Herring分型;以之联合脂肪抑制T2WI可在一定程度上取代髋关节X线检查。

Objective To explore the value of 3D black bone sequence for measuring femoral head extrusion index and evaluating Herring classification of Legg-Calvé-Perthes disease(LCPD).Methods Data of hip joint MRI of 38 children with unilateral LCPD were retrospectively analyzed.Femoral head extrusion indices derived from coronal 3D black bone sequence and coronal fat suppression T2WI were compared to those from anteroposterior hip X-ray,respectively.Taken hip X-ray film as gold standards,receiver operating characteristic(ROC)curve was drawn,and the area under the curve(AUC)was calculated to evaluate the efficacy of 3D black bone sequence and fat suppression T2WI for evaluating Herring classification of LCPD,and DeLong test was performed for statistical comparison.Results Femoral head extrusion index of LCPD based on X-ray film and 3D black bone sequence simulated X-ray film was(11.31±6.16)%and(11.47±5.83)%on control side,respectively,being not significantly different(P>0.05),while was(22.45±9.21)%and(22.82±7.92)%on the affected side,respectively,also being not significantly different(P>0.05)but both higher than that on the control side(both P<0.001).Femoral head extrusion index of LCPD based on fat suppression T2WI was(28.01±2.01)%on affected side and(27.25±1.92)%on control side,respectively,being not significantly different(P>0.05)and both higher than those obtained based on X-ray film(both P<0.001).AUC of 3D black bone sequence and fat suppression T2WI was 0.750—0.938 and 0.625—0.705,respectively.AUC of 3D black bone sequence for evaluating LCPD Herring B type was higher than that of fat suppression T2WI(P<0.05),while no significant difference was found for evaluating other Herring type of LCPD(all P>0.05).Conclusion 3D black bone sequences could be used to measure head extrusion index and assess Herring classification of LCPD,which was expected to replace hip X-ray to some extents combining with fat suppression T2WI.