FUNCTIONAL MRI FOR NEUROSURGICAL PLANNING IN EPILEPSY

癫痫患者谁是手术切除脑病变的候选人必须有某种形式的功能映射，以确定是否可以删除病变，而不产生功能缺陷。 目前用于映射这些患者的语言功能区的程序要么是空间有限的（例如，Wada测试的半球映射），要么是高度侵入性的（使用硬膜下电极的皮层刺激）。功能性磁共振成像（fMRI）有可能取代目前用于神经外科规划的方法。 它是完全非侵入性的，并已被证明能够检测功能性大脑区域。 然而，标准的回波平面成像fMRI方法，基于BOLD激活响应，遭受低空间分辨率，以及对静态Bomicron磁场不均匀性的敏感性，这导致几何图像失真和低信号强度。 这些问题严重限制了功能磁共振成像定位脑活动的能力，神经外科规划。本项目旨在改进功能磁共振成像的方法，并进行全面的比较功能磁共振成像语言映射和目前的金标准皮层刺激的患者。 这项研究将确定功能磁共振成像预测手术结果的能力。 患者将使用皮层刺激和功能磁共振成像绘制语言区域，他们将在手术前和手术后进行行为研究，以测量手术后可能出现的任何缺陷。 该方法的开发将特别关注我们设计的新技术，以减少回波平面功能磁共振成像中的图像失真，同时提高空间分辨率，同时即使在存在场不均匀性的情况下也能产生高度稳健的激活图。 我们的方法包括修改图像采集策略结合新的后处理算法。 这一创新计划将允许手术计划所需的功能性大脑区域的高度稳健的定位。虽然重点是癫痫神经外科规划的功能磁共振成像方法的开发和验证，技术发展将是一般的，可以应用于任何功能磁共振成像研究。 该项目的成功完成可能会使fMRI成为神经外科手术计划中大脑功能定位的主要来源，从而减少对侵入性标测技术的需求。

Epilepsy patients who are candidates for surgical resection of a brain lesion must have some form of functional mapping to determine if the lesion can be removed without creating a functional deficit. The current procedures for mapping language functional areas in these patients are either spatially limited (hemispheric mapping with the Wada test for example) or highly invasive (cortical stimulation using subdural electrodes). Functional MR imaging (fMRI) has the potential to replace the current methods used in Neurosurgical planning. It is completely noninvasive and has been shown to be able to detect functional brain regions. However, the standard echo planar imaging fMRI methods, based on the BOLD activation response, suffer from low spatial resolution, and a sensitivity to static Bomicron magnetic field inhomogeneities which lead to geometric image distortions and low signal intensity. These problems severely limit the ability of fMRI to localize brain activity for Neurosurgical planning. This project is designed to improve fMRI methodology and to perform a thorough comparison between fMRI language mapping and the current gold standard cortical stimulation in patients. This study will determine the ability of fMRI to predict surgical outcome. The patients will have language areas mapped using cortical stimulation and fMRI, and they will undergo behavioral studies pre- and post- surgery in order to measure any deficits that may arise post-surgery. The methodology development will specifically focus on novel techniques we have designed to reduce image distortion in echo planar fMRI, while increasing spatial resolution, and while producing highly robust activation maps even in the presence of field inhomogeneities. Our approach includes modifications to image acquisition strategies in conjunction with new post-processing algorithms. This innovative program will allow for highly robust localization of functional brain regions needed for surgical planning. While the emphasis is on the development and validation of fMRI methodology for Neurosurgical planning in epilepsy, the technical developments will be general and can be applied to any functional MR imaging study. Successful completion of this project may allow fMRI to be used as the primary source of functional localization in the brain for Neurosurgical planning reducing the need for invasive mapping techniques.