Focke Niels K, Symms Mark R, Burdett Jane L, Duncan John S
Department of Clinical and Experimental Epilepsy, Institute of Neurology UCL, London, United Kingdom.
Epilepsia. 2008 May;49(5):786-93. doi: 10.1111/j.1528-1167.2007.01474.x. Epub 2007 Dec 11.
Focal Cortical Dysplasia (FCD) is an important cause for pharmacoresistant epilepsy that can be treated surgically. The identification of the abnormal cortex on standard MRI can be difficult and computational techniques have been developed to increase sensitivity. In this study we evaluate the potential of a novel whole-brain voxel-based technique using normalized FLAIR signal intensity (nFSI) at 3 Tesla.
Twenty-five patients with neuroradiologically reported FCD were included and compared to 25 healthy control subjects using Statistical Parametric Mapping (SPM5). T2 FLAIR scans were intensity normalized and each individual patient was compared against the control group. Each control subject was compared against the remaining control group.
SPM correctly identified the FCD in 88% of cases (22/25) with only one false positive finding in the control group. In all but one of these cases the FCD was the most significant finding in the whole brain. All three missing cases could be detected at lower threshold levels but this would give rise to more false positive findings and thus reduce specificity.
We present a novel technique that uses standard clinical T2 FLAIR scans to automatically detect FCDs. It can give supplementary information to the established T1-based automated techniques and could be useful for additional screening test, to complement the visual reading and clinical interpretation of MRI scans.
局灶性皮质发育不良（FCD）是药物难治性癫痫的一个重要病因，可通过手术治疗。在标准磁共振成像（MRI）上识别异常皮质可能具有挑战性，因此已开发出计算技术以提高其敏感性。在本研究中，我们评估了一种基于体素的全脑新技术在3特斯拉场强下使用标准化液体衰减反转恢复（FLAIR）信号强度（nFSI）的潜力。
纳入25例经神经放射学诊断为FCD的患者，并使用统计参数映射（SPM5）与25名健康对照者进行比较。对T2 FLAIR扫描进行强度标准化，并将每位患者与对照组进行比较。将每位对照者与其余对照组进行比较。
SPM在88%的病例（22/25）中正确识别出FCD，对照组中仅有1例假阳性结果。在除1例之外的所有这些病例中，FCD是全脑中最显著的发现。所有3例漏诊病例在较低阈值水平下均可检测到，但这会导致更多假阳性结果，从而降低特异性。
我们提出了一种使用标准临床T2 FLAIR扫描自动检测FCD的新技术。它可以为已有的基于T1的自动化技术提供补充信息，并可能有助于进行额外的筛查测试，以补充MRI扫描的视觉判读和临床解读。
