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，以便在植入金属装置的情况下对受试者进行核磁共振引导聚焦超声手术（MRgFUS）治疗。相关性：高强度聚焦超声是最有前途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性骨转移。MRI为计划治疗和评估消融结果以及使用磁共振测温法对消融进行非侵入性实时监测提供了出色的组织对比。不幸的是，一些接受骨转移治疗的痛苦患者以前曾植入金属植入物以稳定骨骼，或使用其他设备，如全髋关节置换术，由于严重的图像伪影，禁止使用MRI引导。我们的团队与其他团队一起，对骨科植入物（如脊柱融合术和关节置换术）的MRI进行了实质性的改进。然而，这些3D技术体积大，速度慢，不适合MRgFUS等交互式成像应用。方法：提出的研究旨在通过开发一种全新的快速，交互式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。我们将这些专门应用于MRgFUS有两个具体目标：(1)开发快速，交互式T2和T1加权扫描，可用于治疗前计划和使用对比度增强的治疗后评估；(2)开发MR测温技术，用于在金属植入物存在的情况下实时监测MRgFUS治疗。我们将在离体动物和体内人体研究中验证金属伪影校正，并验证在接受骨膜消融治疗的无金属MRgFUS患者的适当成像性能（对比度和信噪比）。总结：我们将开发快速MRI方法，在金属存在的情况下进行成像，并将其与MRgFUS程序的交互式规划、实时温度监测和后处理评估相适应。在MRgFUS患者的初步验证之后，这项研究将进行更大规模的临床研究，以证明这些方法对金属植入物患者的常规治疗的有效性。

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.