Multi-point MR-ARFI for time-efficient volumetric tissue stiffness imaging

标题：多点MR-ARFI用于时间效率高的体积组织硬度成像 检测和表征表明坏死的组织特性变化的能力对于 消融治疗的成功控制。当组织被消融时，细胞结构、分布发生变化 组织水的性质，以及大分子结构的性质。成像技术，区分和 为了确保消融治疗的成功，准确地描述组织特性的变化是至关重要的。 聚焦超声(FUS)，一种完全非侵入性和非常有前途的介入技术， 能够消融一系列病理，迫切需要改进的方法来检测、监控和解释 由此导致的组织属性的变化。磁共振引导下的FUS(MRgFUS)手术提供了极好的 待治疗组织和待切除正常组织的解剖图像，并可监测温度 改变房水(非脂肪)组织的分布，以确保治疗的有效性和安全性。诊断性 超声用于引导FUS(USgFUS)手术时，解剖图像质量差，限制了手术的进行 能够测量温度，但可以成像随温度变化的组织硬度和机械性能 治疗。尽管MRI可以通过声学引起的位移来测量组织的硬度 辐射力脉冲(MR-ARFI)，通常是在单个点施加的力，仅提供局部 组织硬度的测量。尽管阿尔菲先生可以以高昂的代价顺序审问多个职位 在增加的采集时间中，没有一种时间高效的方法来同时询问分布 在多个点上的组织硬度。 我们在这项研究中的目标是开发和评估一种及时有效的用于体积组织的mr-arfi方法。 僵硬成像。实现这一目标将有三个目标：1)执行和评估#年的效率 交错多个单点MR-ARFI测量；2)同时或接近实施和评估 多点同步MR-ARFI方法；3)评价多点方法的准确性和重复性 MR-ARFI位移测量。 这种新的体积硬度成像方法将使未来的研究能够测量组织硬度 在MRgFUS手术前、中和之后的组织属性，并将组织属性的变化与其他 手术过程中的热剂量和手术后组织的组织状态等因素。 评估组织位移对FUS施加的力的响应将允许有效的远程触诊 MRgFUS治疗期间在多个部位和时间形成的演变中的热损害 程序。如果这种僵硬的变化是坏死的指标，这将增加信息量。 可用于确定成功的结果。

Title: Multi-point MR-ARFI for time-efficient volumetric tissue stiffness imaging The ability to detect and characterize changes in tissue properties that are indicative of necrosis is essential for successful control of ablative therapies. As tissue is ablated, changes occur in cell structure, in the distribution of tissue water, and in the nature of the macromolecular structure. Imaging techniques that discriminate and accurately characterize tissue property changes are critically needed to ensure ablative therapy success. Focused ultrasound (FUS), a completely non-invasive and highly promising interventional technology that is able to ablate a range of pathologies, has a critical need for improved methods to detect, monitor, and interpret the resulting changes in tissue properties. MRI guidance of FUS (MRgFUS) procedures provides excellent anatomic images of tissues to be treated and normal tissues to be spared, and can monitor temperature distribution changes in aqueous (non-adipose) tissues to ensure treatment efficacy and safety. Diagnostic ultrasound, when used for guiding FUS (USgFUS) procedures, has poor anatomic image quality and limited ability to measure temperature, but can image tissue stiffness and mechanical properties that change with treatment. Although MRI can measure tissue stiffness in terms of displacement caused by an acoustic radiation force impulse (MR-ARFI), the force is typically applied at a single point, providing only a local measurement of tissue stiffness. Although MR-ARFI could sequentially interrogate multiple positions at a cost of increased acquisition time, there is not a time efficient method to simultaneously interrogate the distribution of tissue stiffness at multiple points. Our goal in this study is to develop and evaluate a time-efficient MR-ARFI method for volumetric tissue stiffness imaging. This goal will be accomplished with three aims: 1) Implement and evaluate efficiencies in interleaving multiple single-point MR-ARFI measurements; 2) Implement and evaluate simultaneous or near simultaneous multiple-point MR-ARFI methods; 3) Evaluate the accuracy and repeatability of multiple point MR-ARFI displacement measurements. This new method of volumetric stiffness imaging will enable future studies to measure tissue stiffness properties before, during, and after MRgFUS procedures, and to correlate tissue property changes with other factors such as thermal dose during the procedure and the histologic state of the tissue after the procedure. Assessing tissue displacement in response to the applied force of FUS will allow an effective remote palpation of the evolving thermal lesion formed by the MRgFUS treatment at multiple positions and times during the procedure. If this stiffness change is an indicator of necrosis, this will increase the amount of information available to determine a successful outcome.