Understanding the electrical properties of brain tissues

项目摘要 这项R21拨款提案将开发一种新技术，以探索脑电特性的变化。我们将 使用钠磁共振成像（S-MRI）和直接使用 钠测量装置我们还将测量弥散张量，DT-MRI。这些研究将为这部小说做准备 用于癫痫源活动定位的人类转化研究技术。这一进步将 增加可以从癫痫手术中受益的癫痫患者数量。我们的长期目标是设计一个系统 其中MRI和脑电图（EEG）数据输入被转换成覆盖在 术前计划的解剖MRI。这项技术的成功开发将提供具有成本效益和 对更大的癫痫手术候选人群和其他脑损伤患者进行无创术前评估， 疾病 我们将在手术切除人脑后立即测量人脑的电特性。 癫痫患者治疗他们的癫痫病。然后我们将用S-MRI测量这些组织的钠含量 首先，将其与电感耦合等离子体质谱仪直接测量的钠含量进行比较 ICP-MS是一种非常灵敏和准确的设备，用作测量元素含量的金标准， 钠。我们将证明，非侵入性S-MRI在测量大脑钠含量方面与黄金一样准确 标准然后，我们将使用这些数据沿着与DT-MRI和数学模型来计算电 大脑的传导性。我们将证明，从非侵入性S-MRI和DT-MRI沿着获得的数据与 数学模型可以预测脑组织的电导率， 测量. 我们还将研究S-MRI或其与DT-MRI结合定位动物致癫痫脑组织的能力 癫痫模型我们将首先准备癫痫动物。然后我们将测量这些动物的S-MRI和DT-MRI 与发育前的扫描结果相比， 癫痫然后，我们将在动物的大脑中植入脑电图电极，以测量它们大脑的电活动， 定位导致癫痫发作的大脑区域我们将展示非侵入性MRI扫描将定位 癫痫活动区域以及侵入性颅内EEG测量。 鉴于脑电图的局限性，这项研究的成功完成具有巨大的临床意义 源模型和当前的方法来定位癫痫区域进行手术治疗。

PROJECT SUMMARY This R21 grant proposal will develop a novel technology to explore changes in brain electrical properties. We will measure sodium concentrations noninvasively using sodium magnetic resonance imaging (S-MRI) and directly using a sodium-measuring devise. We will also measure diffusion tensor, DT-MRI. These studies will prepare this novel technology for translational human studies for localization of epileptogenic sources of activity. This advancement will increase the number epilepsy patients that can benefit from epilepsy surgery. Our long-term goal is to devise a system where MRI and electroencephalogram (EEG) data input is converted into a conductivity and localization map overlaid on anatomical MRI for presurgical planning. Successful development of this technology will provide cost-effective and noninvasive presurgical evaluation for a much larger population of epilepsy surgery candidates, and for other brain diseases. We will measure the electrical properties of the human brain immediately after they are surgically removed from epilepsy patients to treat their seizure disorders. We will then measure the sodium content of these tissues with S-MRI first, and compare that with directly-measured sodium content using inductively coupled plasma mass spectrometer (ICP-MS) which is a very sensitive and accurate device used as gold standard to measure elemental contents such as sodium. We will show that noninvasive S-MRI is equally accurate in measuring sodium content of the brain as the gold standard. We will then use these data along with DT-MRI and a mathematical model to calculate the electrical conductivities of the brain. We will show that the data obtained from non-invasive S-MRI and DT-MRI along with the mathematical model can predict the electrical conductivity of the brain tissues as accurately as the direct invasive measurements. We will also study the ability of S-MRI or its combination with DT-MRI to localize epileptogenic brain tissues in an animal model of epilepsy. We will first prepare animals with epilepsy. We will then measure S-MRI and DT-MRI in these animals to locate the brain regions that show changes in these scans when compared to scans acquired before they developed epilepsy. We will then implant EEG electrodes in the animal’s brains to measure their brains’ electrical activities and locate the brain regions that cause epileptic seizures. We will show that the noninvasive MRI scans will locate the regions of seizure activity as well as invasive intracranial EEG measurements. The successful completion of this proposed research has tremendous clinical significance given the limitations of EEG source models and current methodologies to localize epileptogenic areas for surgical treatment.