磁共振扩散张量纤维束成像技术在内侧颞叶癫痫中的应用研究

目的采用扩散张量纤维束成像(DTT)技术对内侧颞叶癫痫(mesial temporal lobe epilepsy,mTLE)中特定的脑白质纤维完整性的改变进行研究,探讨其在mTLE中的应用价值。资料与方法 25例单侧mTLE患者(左侧13例,右侧12例)及21名健康自愿者(对照组)纳入本研究。在1.5 T MR扫描仪下行扩散张量成像(DTI)数据采集。采用Trackvis软件对受检者颞叶相关的5对白质纤维束进行追踪显示,测量其整体部分各向异性分数(FA)值。将两组mTLE患者的左、右侧纤维束FA值分别与对照组相应侧纤维束FA值进行两样本t检验。最后将病例组纤维束FA值与临床因素进行相关分析。结果相对于对照组,左侧mTLE组5个患侧纤维束FA值均减低(P<0.05),而对侧仅扣带束(t=2.458,P<0.05)、上纵束(t=2.112,P<0.05)、下纵束(t=2.093,P<0.05)的FA值减低;右侧mTLE组5个患侧纤维束FA值均减低(P<0.05),而对侧仅下纵束FA值减低(t=2.384,P<0.05)。左侧mTLE组左侧钩束FA值与始发年龄呈线性正相关关系(r=0.764,P<0.01),与发病时长呈线性负相关关系(r=-0.678,P<0.05)。结论 DTT可用于颞叶癫痫相关白质纤维束完整性的检测,并有助于mTLE定侧研究,加深对mTLE病理生理机制的进一步理解。

Applied Study of MR Diffusion Tensor Tractography in Medial Temporal Lobe Epilepsy

Objective To evaluate the applied value of diffusion tensor tractography in mesial temporal lobe epilepsy(mTLE).Materials and Methods 25 patients with mTLE(12 right and 13 left side) and 21 healthy controls were enrolled in this study.Diffusion tensor imaging data with 16 diffusion gradient direction were obtained on an 1.5 Tesla MR imaging scanner.Trackvis softwares were used for white matter fibers tracking.Five pairs of white matter fiber tracts involved in the temporal lobe were investigated.The fiber tract fractional anisotropy(FA) were compared with that of normal controls using two sample t-test..Results Compared with normal controls,patients with left mTLE presented decreased FA in the all ipsilateral(P<0.05) and 3 contralateral fiber tracts(P<0.05).While the patients with right mTLE presented decreased FA in the all ipsilateral(P<0.05) and the left inferior longitudinal fasciculus(t=2.384,P<0.05).Furthermore,the lower FAs in left uncinate fasciculus of the left mTLE patients were correlated with the earlier age of seizure onset(r=0.764,P<0.01) and duration of epilepsy(r=-0.678,P<0.05).Conclusion We found widespread reductions in fiber tract FA in patients with mTLE,which were most pronounced ipsilateral to the seizure focus.DTT has potential applications for lateralization of the epileptogenic focus and investigation of changes in structural integrity,and it is significant for investigation of the athophysiological mechanism of mTLE.