MR Guided Focused Ultrasound Surgery near Metal Implants

描述(由申请人提供)：该项目旨在开发和验证磁共振成像(MRI)技术，以便能够在植入金属设备的情况下对受试者进行MR引导的聚焦超声手术(MRgFUS)治疗。相关：高强度聚焦超声是最有前景的新型非侵入性消融方法之一，最近被临床批准用于治疗疼痛的骨转移瘤。MRI为计划治疗和评估消融结果以及使用MR测温仪对消融进行非侵入性实时监测提供了极佳的组织对比。不幸的是，一些接受痛苦的骨转移治疗的患者以前曾植入金属植入物以稳定他们的骨骼，或者使用其他设备，如全髋关节置换，由于严重的图像伪影，禁止使用MRI指导。我们的团队与其他人一起，在脊柱融合和关节置换等骨科植入物附近的磁共振成像方面取得了实质性的改进。然而，这些3D技术体积大、速度慢，不适合交互式成像应用程序，如MRgFUS。方法：拟议的研究试图通过开发一种全新的快速、交互的2D MRI技术来克服这些限制，该技术具有几乎完全的金属附近图像伪影校正。我们将在两个具体目标中将这些专门应用于MRgFUS：(1)开发快速、交互的T2和T1加权扫描，可用于治疗前计划和使用对比度增强进行治疗后评估；(2)开发磁共振测温技术，用于在存在金属植入物的情况下实时监测MRgFUS治疗。我们将在体外动物和活体人体研究中验证金属伪影校正，并验证正在接受骨膜切除术治疗疼痛骨癌的MRgFUS患者的适当成像表现(对比度和信噪比)。摘要：我们将开发快速的磁共振成像方法，在金属存在的情况下以最少的伪影进行成像，并根据交互计划、实时温度监控和MRgFUS程序的治疗后评估而定制这些方法。在我们对MRgFUS受试者进行初步验证之后，这项研究将使一项更大的临床研究能够证明这些方法在金属植入物患者的常规治疗中的有效性。

DESCRIPTION (provided by applicant): This project aims to develop and validate magnetic resonance imaging (MRI) techniques to enable MR-guided focused ultrasound surgery (MRgFUS) treatment of subjects in the presence of implanted metal devices. Relevance: High-intensity focused ultrasound is one of the most promising new non-invasive ablation methods, and was recently clinically approved for the treatment of painful bone metastases. MRI offers excellent tissue contrast for planning treatments and for assessing the results of an ablation as well as for non- invasive real-time monitoring of the ablation using MR thermometry. Unfortunately, some patients with painful bone metastases treatments have previously had metallic implants inserted for stabilization of their bones, or have other devices such as a total hip replacement, which prohibits the use of MRI guidance due to severe image artifacts. Our group, together with others, has made substantial improvements to MRI near orthopedic implants such as spinal fusions and joint replacements. However, these 3D techniques are volumetric, slow, and inappropriate for interactive imaging applications such as MRgFUS. Approach: The proposed research seeks to overcome these limitations by developing a completely new class of rapid, interactive 2D MRI techniques with almost complete image artifact correction near metal. We will apply these specifically to MRgFUS in two specific aims: (1) to develop rapid, interactive T2 and T1 weighted scans that can be used for pre-treatment planning and for post-treatment evaluation using contrast enhancement, and (2) to develop MR thermometry techniques for real-time MRgFUS treatment monitoring in the presence of metal implants. We will validate the metal artifact correction in ex vivo animal and in vivo human studies, and verify appropriate imaging performance (contrast and SNR) in MRgFUS patients without metal who are being treated for periosteal ablations of painful bone cancers. Summary: We will develop rapid MRI approaches to image in the presence of metal with minimal artifacts, and tailor these to the interactive planning, real-time temperature monitoring, and post-treatment evaluation of MRgFUS procedures. Following our initial validation in MRgFUS subjects, this research will enable a larger clinical study to demonstrate efficacy of these methods for routine treatment of patients with metallic implants.