Comprehensive MRI Guidance of Focused Ultrasound Neurosurgery

项目概要/摘要 特发性震颤（ET）是一种使人衰弱的常见运动障碍，患病率高达4%的人口。 ET通常是致残的，书写、进食或饮水的能力降低。患有这种疾病的人经常减少他们的社会交往 因为尴尬，有抑郁的风险。有一些医学疗法可以减轻症状，但 许多患者患有对药物治疗无反应的震颤。深度脑刺激可以很好地工作，但许多 患者不是手术的候选人或更喜欢非手术选择。 MR引导聚焦超声（MRgFUS）是治疗ET的微创方法，适用于以下患者： 是药物治疗难以治愈的聚焦超声（FUS）提供声能，可将病灶局部加热至消融 温度超过60 ℃。FUS与MRI引导（MRgFUS）相结合， 组织消融，通过实时MR测温监测。经颅MRgFUS已用于治疗ET， 并持久减轻症状。 通过我们的临床经验，我们已经确定了艾德几个关键领域，在这些领域，改进的治疗监测可以 大大提高了安全性和有效性。该项目的总体目标是提供全面的MRI反馈 用于经颅聚焦超声，以提高治疗的安全性、效率和效果。我们的具体目标是 以下内容： 目标1：开发实时体积测温技术，以监测热治疗。MRgFUS治疗 目前使用2D脉冲序列进行温度映射监测。在消融过程中，治疗只能是 在飞机中监测，并且峰值温度升高的位置可以发生在飞机之外。为此，我们将开发 实时体积MR温度测量的新方法，并在临床前和志愿者研究中验证这些技术。 目标2：开发监测大脑和颅骨意外发热的方法。头骨吸收来自 应用超声波，这导致头骨和附近的软组织，包括大脑加热。目前没有 仅使用简单的模型来估计这种加热的直接监测以及声处理之间所需的等待时间。在 为此，我们将开发新的，快速的，3D超短回波时间的方法来监测颅骨温度变化， 与全脑体积测温和测试这些方法在研究中的患者接受FUS治疗的ET。 目标3：开发实时治疗监测技术，以早期评估生存能力。关键MR监测- 存储功能包括在创建病变时使病变可视化。我们假设弥散加权成像可以捕捉到 早期时间点的临床有用的病变对比。在这个目标中，我们将开发和验证新的扩散方法 在具有挑战性的FUS换能器环境中进行成像，并在患者研究中测试这些方法。 这项研究将从根本上改善使用MRgFUS治疗原发性震颤，从而推进一项技术， 这可能对这些患者的治疗产生重大影响。

PROJECT SUMMARY/ABSTRACT Essential tremor (ET) is a debilitating, common movement disorder, with prevalence as high as 4% of the population. ET is often disabling, with reduced ability to write, eat, or drink. People with the disorder often curtail their social interactions because of embarrassment and are at risk for depression. There are medical therapies that can reduce symptoms, but many patients have tremor that is not responsive to medical treatment. Deep brain stimulation can work well, but many patients are not candidates for surgery or would prefer a non-surgical option. MR-guided Focused Ultrasound (MRgFUS) is a minimally invasive method of treating ET that works in patients who are refractory to medical therapy. Focused ultrasound (FUS) delivers acoustic energy that focally heats lesions to ablative temperatures of greater than 60C. The combination of FUS with MRI guidance (MRgFUS) enables precisely localized tissue ablation, monitored by real-time MR thermometry. Transcranial MRgFUS has been used to treat ET with significant and durable reduction in symptoms. Through our clinical experience, we have identified several critical areas where improved treatment monitoring could dramatically increase safety and effectiveness. The overall goal of this project is to provide comprehensive MRI feedback for transcranial focused ultrasound to improve the safety, efficiency and efficacy of treatment. Our specific aims are the following: Aim 1: Develop real-time volumetric thermometry techniques to monitor thermal treatment. MRgFUS treatments are currently monitored using a 2D pulse sequence for temperature mapping. During ablation, the treatment can only be monitored in a plane, and the location of peak temperature rise can occur outside of the plane. In this aim, we will develop new methods for real-time volumetric MR thermometry and validate these techniques in pre-clinical and volunteer studies. Aim 2: Develop methods to monitor unintended heating of the brain and skull. The skull absorbs energy from the applied ultrasound, which results in heating of the skull and the nearby soft tissue, including the brain. There is currently no direct monitoring of this heating, and the required wait time between sonications is only estimated using simple models. In this aim, we will develop new, rapid, 3D ultrashort-echo-time methods for monitoring skull temperature changes combined with whole-brain volumetric thermometry and test these methods in studies of patients undergoing FUS treatment for ET. Aim 3: Develop real-time treatment monitoring techniques to give early assessment of viability. Critical MR moni- toring functions include visualizing the lesion as it is created. We hypothesize that diffusion-weighted imaging can capture clinically useful lesion contrast at early time points. In this aim, we will develop and validate new methods for diffusion imaging in the challenging environment of a FUS transducer and test these methods in studies of patients. This research will fundamentally improve the treatment of essential tremor using MRgFUS, thereby advancing a tech- nology that can have a significant impact on the treatment of these patients.