MR-Guided RF Ablation ofthe Liver

磁共振引导射频肝脏消融术

• 批准号: 8555397
• 负责人: John M. Pauly
• 金额: $ 22.83万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-22 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8555397
• 关键词: Ablation; Adipose tissue; Algorithms; Animals; Cancer Intervention; Clinical; Deposition; Detection; Devices; Diagnostic; Electric Conductivity; Electrodes; Electromagnetic Fields; Elements; Equation; Evolution; Family suidae; Feasibility Studies; Feedback; Frequencies; Goals; Heating; Image; Intervention; Lesion; Liver; Liver neoplasms; Magnetic Resonance Imaging; Maps; Monitor; Operative Surgical Procedures; Pathway interactions; Patients; Performance; Physiologic pulse; Procedures; Process; Protons; Radiofrequency Interstitial Ablation; Research Infrastructure; Shapes; Signal Transduction; Slice; Solutions; Survival Rate; System; Techniques; Temperature; Testing; Therapeutic; Thermometry; Time; Tissue Sample; Tissues; Work; bone; cancer therapy; density; flexibility; improved; in vivo; magnetic field; minimally invasive; reconstruction; success; tool; treatment planning; tumor; vector

Radiofrequency ablation (RFA) is emerging as an effective image-guided minimally invasive therapeutic alternative to surgical treatment of cancer tumors. RFA appears well suited to nonresectable tumors in liver. The ablation process is highly dependent on the electrical conductivity of these tissues yet there is no easy way to predict the current pathways or how focused the current will be on the tumor. For example, bone and fatty pockets can shield tumor from ablation currents. Consequently, repeatable ablation volumes are difficult to produce. Our goal is to enhance the planning, control and efficacy of tumor ablation by using an MRI system that can map RF ablation currents local to the electrodes during ablation and map thermal changes. RF current maps will show where power is being deposited, and MR thermometry will show where heat flowed during the ablation. Our approach exploits a new MRI technique that estimates RF current density in tissue. The ablation electrode can be injected with RF currents at the resonant frequency of the MRI scanner, and can also act as an MRI receiver. The MRI scanner can directly image the intense magnetic fields associated with the ablation current, and then derive the local electrode current flow to tissue. In our preliminary work, we have already visualized the current flow in an MR compatible ablation electrode. These tests demonstrated that fatty tissue effectively insulates and blocks the ablation current. Moreover, the current pathway itself lights up high conductivity tissue and creates a medically significant contrast. To fully exploit this capability, we will merge RF current mapping with MR thermometry and ablation devices to form a comprehensive interventional MRI system for RF ablation. Enhanced RF hardware, pulse sequences and reconstructions will be developed. Upon completion, we will perform ex-vivo tissue sample and in-vivo animal studies to demonstrate the clinical potential of this system.

射频消融 (RFA) 正在成为一种有效的图像引导微创治疗方法 癌症肿瘤手术治疗的替代方案。 RFA 似乎非常适合肝脏中不可切除的肿瘤。 消融过程高度依赖于这些组织的导电性，但没有简单的方法 预测当前路径或电流在肿瘤上的聚焦程度的方法。例如，骨头和 脂肪袋可以保护肿瘤免受消融电流的影响。因此，可重复的消融体积是 难以生产。 我们的目标是通过使用 MRI 系统来增强肿瘤消融的计划、控制和功效，该系统可以 绘制消融过程中电极局部的射频消融电流并绘制热变化图。射频电流 地图将显示电力沉积的位置，而 MR 测温法将显示热量在过程中流动的位置 消融。我们的方法利用了一种新的 MRI 技术来估计组织中的射频电流密度。这 消融电极可以在 MRI 扫描仪的共振频率下注入射频电流，并且可以 也可用作 MRI 接收器。 MRI 扫描仪可以直接对相关的强磁场进行成像 与消融电流，然后导出流向组织的局部电极电流。在我们的前期工作中， 我们已经可视化了 MR 兼容消融电极中的电流。这些测试 证明脂肪组织有效地隔离和阻止消融电流。此外，当前 通路本身会照亮高电导率组织并产生医学上显着的对比。 为了充分利用这一功能，我们将射频电流测绘与 MR 测温和消融相结合 设备形成用于射频消融的综合介入 MRI 系统。增强型射频硬件、脉冲 将开发序列和重建。完成后，我们将进行离体组织样本 和体内动物研究，以证明该系统的临床潜力。