Better localisation for epilepsy surgery by optimising simultaneous EEG and functional MRI recordings at 7T

通过优化 7T 同步脑电图和功能性 MRI 记录，更好地定位癫痫手术

• 批准号: 2886505
• 金额: --
• 依托单位: King's College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2886505
• 关键词: Better; localisation; epilepsy; surgery; optimising

For adults and children with focal epilepsy, surgical removal of the brain region responsible for seizure generation is the only possible complete cure. This can remove dependence on medication, and dramatically improve quality of life. Surgical success relies on accurate localisation of the generators of epileptic activity via imaging techniques such as MRI and electroencephalography (EEG). These two key modalities can be combined; epileptic activity measured in EEG is used as a model of expected changes in functional MRI timeseries. This provides a high spatial resolution map showing the areas with signalchanges associated with the epileptic activity that has been shown to be a useful localisation method [1].However, EEG-fMRI is limited by fMRI sensitivity that typically measures signal changes of 1-2%. Ultra-high field 7T MRI offers a solution because fMRI signal changes are substantially increased to 5-10% and this could dramatically improve the technique's sensitivity and spatial specificity. However, simultaneous EEG-fMRI at 7T is a significant technical challenge [2]. This project will design and test EEG configurations for use at 7T so it can be used in patient populations. This will include investigating tissue heating and EEG system design solutions to mitigate this risk. Further, the impact of each modality on the other in terms of data quality will be characterised and the EEG system hardware configuration redesigned to optimise signal quality. This may also encompass potential algorithmic development to improve image quality, including AI methods to improve upon current denoising approaches. Having optimised 7T EEG-fMRI an initial pilot investigation of its utility in epilepsy is envisaged.Aim of the investigation (up to 150 words): This project will design and test EEG configurations for use at 7T so it can be used in patient populations. This will include investigating tissue heating and EEG system design solutions to mitigate this risk. Further, the impact of each modality on the other in terms of data quality will be characterised and the EEG system hardware configuration redesigned to optimise signal quality. This may also encompass potential algorithmic development to improve image quality, including AI methods to improve upon current denoising approaches. Having optimised 7T EEG-fMRI an initial pilot investigation of its utility in epilepsy isenvisaged.Objective 1: Determine safety limits for operation of new 7T compatible EEG systemWe will test and optimise custom configured EEG system designs with the project partner Brain Products. This will involve thermometry and thermal imaging testing in phantoms and human subjects. Simulation using in-silico models using the electromagnetic field (EM) simulation software package Sim4life may also be involved informed by the results of initial experimental testing. Different cable routings and the size and distribution of impedance within the wires will be tested. One of the main limitations of new high field 7T scanners is the high spatial variability in the RF transmit field (B1+) owing to the shorterwavelength required that increases tissue interactions. Reductions to the B1+ field can be seen in the figure c below from initial testing with associated imaging artefacts in figure b. One important method for mitigating this is transmit RF coils that provide different fields from multiple coil elements that, when optimally combined, reduce B1 field variability and could be used to reduce interactions with the EEG cap. This testing will therefore be performed for both single and parallel transmit MRI coils, and modes of operation that limit EEG interactions explored.Months 1-6, heating risk assessment and reduction. Months 4-12 exploration of risk reduction using parallel transmit modes of operation.Objective 2: Characterise and mitigate artefacts for new 7T compatible EEG systems at 7T. & Objective 3: MRI Protocol development and data assessme

对于患有局灶性癫痫的成人和儿童，手术切除负责癫痫发作的大脑区域是唯一可能的完全治愈方法。这可以消除对药物的依赖，并显着提高生活质量。手术的成功依赖于通过MRI和脑电图（EEG）等成像技术对癫痫活动发生器的准确定位。这两种关键模式可以结合起来; EEG中测量的癫痫活动用作功能性MRI时间序列中预期变化的模型。这提供了一个高空间分辨率的地图，显示与癫痫活动相关的信号变化区域，这已被证明是一种有用的定位方法[1]。然而，EEG-fMRI受到fMRI灵敏度的限制，通常测量1- 2%的信号变化。超高场7 T MRI提供了一种解决方案，因为fMRI信号变化大幅增加到5-10%，这可以显着提高该技术的灵敏度和空间特异性。然而，在7 T下同时进行EEG-fMRI是一个重大的技术挑战[2]。本项目将设计和测试在7 T下使用的EEG配置，以便其可用于患者人群。这将包括研究组织加热和EEG系统设计解决方案，以缓解该风险。此外，将描述每种模态在数据质量方面对其他模态的影响，并重新设计EEG系统硬件配置以优化信号质量。这也可能包括潜在的算法开发，以提高图像质量，包括AI方法，以改善当前的去噪方法。优化7 T脑电图功能磁共振成像的初步试点调查，其效用在epilepsy是considered.Aim的调查（最多150字）：该项目将设计和测试脑电图配置使用在7 T，使它可以用于患者人群。这将包括研究组织加热和EEG系统设计解决方案，以缓解该风险。此外，将描述每种模态在数据质量方面对其他模态的影响，并重新设计EEG系统硬件配置以优化信号质量。这也可能包括潜在的算法开发，以提高图像质量，包括AI方法，以改善当前的去噪方法。优化7 T EEG-fMRI的初步试点调查其效用在epilepsy isconsidered.Objective1：确定新的7 T兼容的EEG systemWe将测试和优化自定义配置的EEG系统设计与项目合作伙伴脑产品操作的安全限制。这将涉及在幻影和人类受试者中进行温度测量和热成像测试。还可能涉及使用电磁场（EM）模拟软件包Sim 4life的计算机模拟模型的模拟，并根据初始实验测试的结果进行通知。将测试不同的电缆布线以及导线内阻抗的大小和分布。新型高场7 T扫描仪的主要限制之一是RF发射场（B1+）的高空间变异性，这是由于所需的较短波长增加了组织相互作用。从图B中的相关成像伪影的初始测试中，可以在下图c中看到B1+场的减少。缓解这种情况的一种重要方法是发射RF线圈，其提供来自多个线圈元件的不同场，当最佳组合时，减少B1场可变性，并可用于减少与EEG帽的相互作用。因此，将对单个和并行发射MRI线圈进行本测试，并探索限制EEG相互作用的操作模式。第1-6个月，加热风险评估和降低。第4-12个月探索使用并行传输操作模式降低风险。目标2：表征并减轻新的7 T兼容EEG系统在7 T下的伪影。&目标3：MRI方案开发和数据评估