MR扩散张量成像在膝关节前交叉韧带的初步应用

The demonstration of anterior cruciate ligament using MR diffusion tensor imaging:apreliminary study

目的:探讨采用3.0T磁共振对膝关节前交叉韧带进行磁共振扩散张量成像(DTI)及纤维束示踪成像(FT)的可行性。方法:对25名健康志愿者进行膝关节DTI检查,男15例,女10例,年龄21~40岁,平均34.6岁。采用单次激发自旋回波平面成像序列,在工作站进行纤维束示踪三维模拟成像,计算前交叉韧带的纤维束长度及平均FA值、ADC值,比较不同性别的FA值及ADC值差异,并分析同一操作者在不同时间测量结果的一致性。结果:25名受检者中16例前交叉韧带显示三维纤维束结构,4例显示多束,5例未显示规则的纤维束。所显示的平均纤维长度为(13.79±1.75)^(25.43±3.37)mm.。全部受试者前交叉韧带平均FA值为0.457±0.058,平均ADC值为1.419±0.289,无性别差异。比较同一测量者在不同测量时间的FA和ADC测量值,其可信度和组内相关系数均较好。结论:采用3T MR成像系统能成功完成正常前交叉韧带DTI和DTT,并可显示正常前交叉韧带的双束结构。

Objective To assess the feasibility of demonstrating the fibric structure of anterior cruciate ligament （ACL） using MR diffusion tensor imaging （DTI） and DTT,and analyze the DTI and DTT parameters of ACL. Methods： 25 healthy volunteers （15 males,10 females,age range 21 to 40 years,mean age 34. 6 years） were scanned at 3T MR scanner u-sing 8ch knee coil. A single-shot spin-echo-based echo-planar imaging sequence was performed at each subject using b value of 400s/mm2 ,the number of diffusion directions for the DTI sequence was 32. Routine PDW and T 2 W tained. The fiber tracking and other post-processing steps were carried out by a radiologist on Philips workstation. Thelength of ACL,FA and ADC values of ACL were measured. The results of the same opared. Results： Reconstructed DTI and DTT（20 /25 ） were of good quality. Tractography illustrated nicely the 3D courses of double-bundle structure in 16 cases. The average length ofACL fiberswas （13. 79± 1. 75）mm to （25. 43± 3. 37）mm. The average FAvalues ofACL were 0. 457土0. 058. The averageADCvalues of ACL were 1. 4 1 9 ± 0 .tic difference of FA value and ADC value in different gender. Among the results of the same measurer at different time,the intraclass correlation coefficient and the alpha coefficient were pretty good. Conclusion： DTI and DTT for normal ACL canbe accomplished by 3T MR scanner,and DTI and DTT can demonstrate the double-bundle structure of ACL.