MR 3D SPGR、3D FIESTA和2D SE/FSE序列对外伤性膝关节软骨损伤的分级诊断研究

Retrospective Clinical Evaluation of Articular Cartilage Abnormalities of Traumatic Knee with MR 3D SPGR,3D FIESTA and 2D SE/FSE Sequences

目的回顾性研究外伤性膝关节关节软骨的损伤发生率及程度,比较三维扰相梯度回波序列(3DSPGR)、三维稳态采集快速成像序列(3D FIESTA)和膝关节常规检查序列(2D SE/FSE)在诊断外伤性膝关节软骨损伤中的准确性。资料与方法45例患者的46个外伤膝关节,行手术治疗前均进行了多序列的MRI,包括膝关节常规MRI(SE T1WI,FSE PD/T2WI),3D SPGR和3D FIESTA序列。运用改良的Noyes分类系统来评价膝关节软骨面的损伤等级,每个膝关节的关节面包括:股骨外侧髁(LFC)、股骨内侧髁(MFC)、胫骨外侧平台(LTP)、胫骨内侧平台(MTP)、股骨滑车(Trochlea)和髌骨(Patella)。以手术结果为"金标准",比较各序列发现软骨损伤的敏感性、特异性、准确性、阳性及阴性预测值。用Wilson评分法计算敏感性和特异性的95%可信区间,用McNemar统计法的双尾精确表来比较不同MRI序列对软骨分级诊断的显著性差异。结果根据手术结果,软骨形态改变的发生率为43%(118/276),软骨缺损的发生率为23%(63/276)。各个关节面软骨损伤的发生率无明显差异。MR图像(3D SPGR、3D FIESTA、3D SPGR结合常规MRI)表现与手术结果的完全一致率分别为53%、60%和85%,之间差异无统计学意义。但是3D SPGR结合常规MRI序列评价软骨损伤的敏感性、特异性、阳性预测值和阴性预测值均为最高,分别为73%、98%、95%和90%。结论3D SPGR和3D FIESTA序列在诊断膝关节软骨病变时无明显差异。3D SPGR结合常规MRI序列,不仅可以在合理的扫描时间内提高诊断软骨病变的准确性,而且还可对膝关节的其他组织结构做出全面的评价。

Objective To study the prevalence and degrees of traumatic injuries of the articular cartilage of knee,and compare the diagnostic accuracy of three-dimensional spoiled gradient echo（3D SPGR）,conventional MR 2D SE/FSE and three-dimensional fast imaging employing steady state acquisition（3D FIESTA）.Materials and Methods 46 knees of 45 patients who had history of knee trauma were collected in our study,which all received a series of established MR imaging before arthroscopies or open knee surgery.The sequences of MRI included conventional MRI（SE T1WI,FSE PD/T2WI）,3D SPGR and 3D FIESTA.The results of surgery were used as reference standard,and a modified version of the Noyes classification system was applied for the evaluation of the following six articular surfaces：lateral femoral condyle（LFC）,medial femoral condyle（MFC）,lateral tibial plateau（LTP）,medial tibial plateau（MTP）,trochlea and patella.The Wilson score method was used to determine the 95% confidence intervals for sensitivity and specificity.The two-tailed exact form of the McNemar statistic was used as the test of significance comparing the grading results of the different MR images.Results The prevelence of morphological cartilage changes was 43%（118/276）,and the incidence of cartilage defects was 23%（63/276）,according to the grading result of surgery.All the rates of exact match between the grading results of different MRI procedures and surgery had no significant difference,including 53% of 3D SPGR,60% of 3D FIESTA,and 85% of the combination of 3D-SPGR and conventional MRI.The 3D SPGR combined with conventional MR sequence had the highest sensitivity（73%）,specificity（98%）,positive predictive value（95%） and negative predictive value（90%）.Conclusion Both 3D SPGR and 3D FIESTA imaging have similar advantages in detecting cartilage lesions of knee.The diagnostic accuracy of the articular cartilage and comprehensive information of adjacent tissues can be improved by combination 3D SPGR and conventional MRI within a reasonable time.