磁共振多种成像方法在颞叶癫痫的综合诊断

目的 应用MR不同成像方法探讨MRI对颞叶癫痫的诊断价值。资料与方法 设对照组40例，颞叶癫痫组(TLE)20例，颞叶外癫痫组(ELE)21例。应用MRI测量并比较对照组及TLE、ELE组间海马结构(HF)体积差异，行TLE组致痫侧评判。应用扩散加权成像(DWI)测量并比较对照组与TLE患侧、对侧、ELE组间表观弥散系数(ADC)值差异。应用1H MRS对各组分别进行单体素波谱(SVS)和化学位移成像(CSI)，SVS时比较TLE患侧、对侧及对照组各代谢物比值差异，对TLE组行致痫灶定侧诊断。CSI时分析HF从前到后NAA／(Cho Cr)的变化规律。结果TLE组患侧HF体积、NAA／(Cho Cr)值下降，ADC值升高，与对照组差异有显著性。定量MRI、SVS对TLE组定侧敏感性分别为70％、85％，特异性分别为87．5％、95％。CSI示HF的NAA／(Cho Cr)与HF部位间呈直线相关关系，TLE时前部改变较后部大。结论 定量MRI、SVS可帮助TLE致痫灶定侧，SVS更敏感、特异，两者结合后价值更大。CSI显示HF从前到后代谢物浓度渐变现象，TLE组头部改变较尾部大。DWI可作为MRI诊断颞叶癫痫的补充。

Evaluation of Multiple MR Imaging Technique Combination in Diagnosing Temporal Lobe Epilepsy

Objective To evaluate several MR imaging techniques in diagnosing temporal lobe epilepsy.Materials and Methods This study included control group (n=40), temporal lobe epilepsy (TLE) group (n=20) and extratemporal lobe epilepsy (ELE) group (n=21). Quantitative MRI, DWI and 1 H MRS were performed in all subjects. The border and volume of bilateral hippocampus formation (HF) were identified and measured. 1 H MRS included single-voxel spectroscopy (SVS) and chemical shift imaging (CSI). The metabolic data of both SVS and CSI were recorded and calculated. The value of apparent diffusion coefficient (ADC) of HF was measured on ADC image.Results In TLE group, the ipsilateral HF showed smaller volume, decreased NAA/(Cho Cr) ratio and higher ADC value than that in control group with significant difference. For localizing the diseased side in TLE group, quantitative MRI had a specificity of 70% and a sensitivity of 87.5%, while 1 H MRS had 85% and 95%, respectively. On CSI, NAA/(Cho Cr) ratio was lower in anterior part than in the posterior part of HF. Conclusion 1H MRS is superior to quantitative MRI in localizing the seizure side. A combination of quantitative MRI and 1 H MRS can improve the diagnosis of TLE. DWI is helpful for confirming the diagnosis of TLE. NAA/(Cho Cr) ratio is different from anterior part to posterior part in HF.