MR扩散张量成像在颞叶癫痫的初步研究

Preliminary Study of MR Diffusion Tensor Imaging in Temporal Lobe Epilepsy

目的应用MR扩散张量成像技术(DTI)分析不同时期颞叶癫痫(TLE)患者的海马扩散变化规律,并使用扩散张量纤维束成像技术(DTT)初步观察TLE患者的穹窿改变。资料与方法对临床诊断的55例不同时期TLE患者(发作后早期13例,发作间期42例)和32名健康志愿者行常规MRI和DTI检查,定量测量双侧海马的平均扩散系数(DCavg)、部分各向异性(FA)、1-容积比(1-VR)和相对各向异性(RA)值并统计,同时对2例TLE患者和4名健康志愿者行穹窿纤维束重组。结果发作后早期:患侧、对侧海马DCavg显著高于正常对照组(P值分别为0.013和0.001),三组间FA、1-VR和RA差异均有统计学意义(P<0.001),患侧<对侧<正常;发作间期:患侧、对侧和正常对照组海马DCavg差异有统计学意义(P<0.001),患侧>对侧>正常,三组间FA、1-VR和RA差异均有统计学意义(P<0.001),患侧<对侧<正常。发作后早期组与发作间期组比较:患侧海马DCavg差异有统计学意义(P=0.004)。TLE患者双侧穹窿较正常人细小,患侧穹窿可见部分纤维中断。结论TLE发作后不同时期的海马扩散变化特点不同,DTI可以反映其病理学改变;DTT能够初步显示TLE患者的穹窿改变。

Objective To discuss the changing discipline of parameters of diffusion tensor imaging（DTI） in hippocampi, and virtually dissect the fornix using DTT in patients with TLE in different stage. Materials and Methods 55 patients of TLE with different timing （ postictal period in 13 patients, interictal period in 42 patients） and 32 healthy volunteers received conventional and DTI scanning. The DCavg, FA, 1-VR and RA of bilateral hippocampi were measured respectively and DTT was performed in 2 patients and 4 healthy controls. Results Parameters in the hippocampi of postictal patients ： The DCavg in ipsilateral and contralateral sides was higher than that in control group （P value was 0.013 and 0.001 respectively）. The FA,1-VR,RA had significant differences among the three groups （P 〈0.001 ） , the values of the above parameters in ipsilateral side were lower than that in contralateral side, the contralateral side was lower than that in control group. Parameters in the hippocampi of interictal patients ： The DCavg in ipsilateral side, contralateral side and control group had significant differences among the three groups （ P 〈 0. 001 ） , the DCavg in ipsilateral side was higher than that in contralateral side and the contralateral side higher than that in control group. The FA, 1-VR, RA had significant differences among the three groups （ P 〈 0. 001 ） , the values of the above parameters in ipsilateral side were lower than that in contralateral side and the contralateral side lower than that in control group. There was statistically significant difference in DCavg of the ipsilateral hippocampi between postictial and interictial patients （P = 0. 004）. Bilateral reduction and interruption in anisotropy was observed in the fomix of patients with TLE, especially in ipsilateral side. Conclusion Diffusion changes in hippocampi of different periods of TLE are different and DTI can reflect its pathologic changes. DTT can display abnormalities of the fornix in patients with TLE.