Actively Shimmed Needles for Interventional MRI

用于介入 MRI 的主动匀场针

基本信息

批准号：
9906225
负责人：
Saikat T. Sengupta
金额：
$ 23.3万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2023-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9906225
关键词：
3-Dimensional Ablation Biopsy Bismuth Bolus Infusion Brachytherapy British Calibration Categories Consumption Electronics Equipment Excision Family suidae Financial compensation Gel Goals Image Intervention Lead Magnetic Resonance Imaging Magnetism Measurement Mechanics Metals Methods Modeling Monitor Morphologic artifacts Muscle Needles Outcome Pattern Phase Physicians Planet Earth Positioning Attribute Predisposition Procedures Radioactive Resolution Safety Sea Seawater Seeds Shapes Ships Signal Transduction Solid Speed Stainless Steel Structure System Techniques Technology Temperature Testing Thermometry Thinness Time Tissue imaging Tissues Titanium Tube Variant Visualization Water Work World War II base biomaterial compatibility brass design experimental study falls improved instrumentation interest magnetic field metallicity model design nitinol novel operation prevent public health relevance quantitative imaging real time monitoring simulation targeted treatment therapy design tumor

项目摘要

PROJECT SUMMARY / ABSTRACT Needle artifacts have been a long unsolved challenge in the field of Interventional MRI. The large difference in magnetic susceptibilities between an MR compatible metallic needle or stylet and the surrounding water containing tissue induces significant field perturbations in the vicinity of the needle, which results in signal loss due intra-voxel dephasing, image distortions and signal pileups due to voxel mismapping. These artifacts limit to various extents almost every interventional MRI procedure by obscuring and distorting targets and preventing accurate imaging of the region of interest. This results in reduced targeting accuracies, increased procedure times, inability to monitor therapy and ultimately, reduction in the efficacy of MRI guided procedures. The goal of this proposal is to therefore introduce a proof-of-concept solution for this problem that is inspired by degaussing coil technology used in ships and submarines for defense against magnetic field sensitive sea mines. We propose to develop an active degaussing or shim insert for compensation of needle induced ΔB0 and demonstrate correction of susceptibility artifacts in ex-vivo tissue experiments at 3 Tesla. Aim1a of this work is dedicated to the simulation of needle and stylet induced field deviations at 3 Tesla that will include the influence of needle material, tip shape and orientation. Aim 1b will be focused on the simulation of shim fields and modeling of active shim coils that will compensate the field variations estimated in Aim 1a. The goal in Aim 2 will be the actual fabrication and testing of the needle and needle shim inserts, along with the appropriate electronics for operation of the DC shim coils during imaging. In-scanner calibration and phantom tests will follow bench testing for shim insert coils. Mitigation of artifacts induced by Stainless Steel, Titanium, Nitinol and Brass needles and stylets will be demonstrated in gel phantoms at arbitrary orientations. Finally the goal in Aim 3 will be the demonstration of needle artifact compensation in two different ex-vivo MR guided studies, a biopsy targeting study and an MR thermometry precision experiment. The goal in the first will be to show improved qualitative and quantitative imaging of tissue around the needle and in the second will be to show improved precision of temperature measurements by image phase difference based methods. If successful, the proposed work can spur needle and stylet designs that are self compensated for induced fields for use in a wide spectrum of interventional MRI applications at high field.

项目摘要 /摘要在介入MRI领域，针伪影一直是一项长期未解决的挑战。很大的差异 MR兼容金属针或样式与周围水之间的磁敏感性包含组织在针头附近诱导明显的场扰动，从而导致信号损失由于体素不抗压导致的素内蒸发，图像扭曲和信号堆积。这些文物限制了通过掩盖和扭曲目标和扭曲目标和防止对目标区域的准确成像。这导致靶向准确性降低，提高程序时间，无法监测治疗，最终降低了MRI引导程序的效率。因此，该建议的目的是为此问题引入概念验证解决方案。用于防御磁场敏感海的船舶和潜艇中使用的抽气线圈技术地雷。我们建议开发有效的脱气或垫片插入物以补偿针头ΔB0 并证明了3特斯拉的前体组织实验中对易感性伪影的纠正。 AIM1A 工作专门用于模拟针和样式诱发的田野出发，在3特斯拉，其中包括针料，尖端形状和方向的影响。 AIM 1B将重点放在垫片场的模拟上并建模活跃的垫片线圈，以补偿目标1a中估计的场变化。目标的目标 2将是针和针垫片插入物的实际制造和测试，以及适当的成像过程中直流垫圈线圈操作的电子设备。扫描仪校准和幻影测试将遵循垫片插入线圈的台式测试。不锈钢，钛，尼替诺和黄铜针和样式将在任意方向的凝胶幻像中展示。最后目标的目标 3将是两个不同的前体MR指导研究中的针伪影补偿的证明活检靶向研究和MR温度准确实验。首先的目标是显示改进针对针周围的组织的定性和定量成像，第二个将显示通过基于图像相差的方法提高了温度测量的精度。如果成功，拟议的工作可以刺激针和样式设计，这些设计是自我补偿的引起的领域，以便在高场上的大量介入MRI应用。