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）是一种有效的图像引导微创治疗方法