Urbach H, Mast H, Egger K, Mader I
Deptartment of Neuroradiology, University Medical Center Freiburg, Breisacher Str. 64, 79106, Freiburg, Deutschland.
Clin Neuroradiol. 2015 Oct;25 Suppl 2:151-5. doi: 10.1007/s00062-015-0387-x. Epub 2015 Apr 8.
Primary goal of magnetic resonance imaging in epilepsy patients is to detect epileptogenic lesions with small lesions best detectable on a 3D FLAIR SPACE sequence with 1 mm(3) voxels. Morphometric analysis of 3D T1-weighted data sets helps to find subtle lesions and may reveal the true extent of a lesion. In further presurgical work-up, language lateralization and spatial relationship of epileptogenic lesions to eloquent cortex and white matter tracts must be evaluated. With clear left lateralization language, fMRI is sufficient; in atypical lateralizations, Wada test and electrical stimulation mapping may be added. Primary motor cortex and corticospinal tract on one and visual cortex and optic radiation on the other side are displayed with fMRI and diffusion tensor tractography. For the corticospinal tract a "global" tracking algorithm, for the optic radiation including Meyer' loop, which may be damaged in anterior temporal lobe resections, a probabilistic algorithm is best suited.
癫痫患者磁共振成像的主要目标是检测致痫性病变，小病变在体素为1立方毫米的三维液体衰减反转恢复（FLAIR）空间序列上最易检测到。对三维T1加权数据集进行形态计量分析有助于发现细微病变，并可能揭示病变的真实范围。在进一步的术前评估中，必须评估致痫性病变与明确的皮质及白质束的语言功能区定位和空间关系。对于明确的左侧语言功能区定位，功能磁共振成像（fMRI）就足够了；在非典型定位的情况下，可能需要增加Wada试验和电刺激图谱。通过fMRI和弥散张量纤维束成像可以显示一侧的初级运动皮质和皮质脊髓束以及另一侧的视觉皮质和视辐射。对于皮质脊髓束，“全局”追踪算法最合适；对于视辐射，包括在颞叶前部切除术中可能受损的迈耶袢，概率算法最为适用。
