Optimization of Catheter Antennas for Intravascular MR

血管内 MR 导管天线的优化

• 批准号: 6989822
• 负责人: CLAUDIA M HILLENBRAND
• 金额: $ 26.6万
• 依托单位: INTERVENTIONAL IMAGING, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2007-08-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6989822
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; clinical biomedical equipment; computer simulation; diagnostic catheterization; heart catheterization; heart imaging /visualization /scanning; kidney imaging /visualization; magnetic resonance imaging; phantom model; radiowave radiation; swine

DESCRIPTION (provided by applicant): This proposal intends to optimize catheter-based micro radio frequency antennas used in MR-guided, intravascular interventions for high resolution imaging of the arterial wall. A resolution of approximately 200 microns is needed to depict atherosclerotic plaque components in a diseased vessel wall. RF antennas must provide a high signal-to-noise ratio (SNR) to keep acquisition time (TA) short during interventions. Our previous work showed that simple changes in coil winding patterns can double SNR and reduce TA by 4. Thus, we focus on an in-depth optimization of catheter-coils with respect to their SNR. For this purpose, an extensive computer simulation program will be developed which calculates 3D-SNR maps as a function of the antenna geometry and orientation relative to BO. In order to find the best antenna design for a given application, this software will be specifically used to: 1) perform a formal comparison of common intravascular coils (e.g. loop vs. opposed solenoid coil), and 2) investigate possible improvements in SNR by changing geometry through hybrid combination of multiple designs (e.g. by adding loops to an opposed solenoid coil). Design changes necessitate recalculation of the SNR map. When comparing different coils, the best design will be chosen based on the highest SNR calculated at the anticipated location of the wall in a cross-sectional slice through vessel and center of the coil. We will restrict our optimization to coils for coronary and renal artery imaging and construct potentially useful designs identified by simulations using surface mount or micro fabrication technology. All assembled devices will be tested in MR phantom imaging. SNR maps will be acquired at multiple orientations. Measured SNR maps will be compared with simulation data and simulation accuracy for all coils manufactured will be evaluated. Finally, the best designs will be tested in vivo in a porcine animal model. We anticipate that this project will lead to identification and prototyping of SNR-optimized catheter coils for further testing in animal models of vascular disease in Phase II.

描述（由申请人提供）：本提案旨在优化MR引导血管内介入术中使用的基于导管的微型射频天线，以实现动脉壁的高分辨率成像。需要大约200微米的分辨率来描绘患病血管壁中的动脉粥样硬化斑块成分。射频天线必须提供高信噪比（SNR），以在干预期间保持较短的采集时间（TA）。我们以前的工作表明，线圈绕组模式的简单变化可以使SNR增加一倍，并将TA降低4。因此，我们专注于对导管线圈的SNR进行深入优化。为此，将开发一个广泛的计算机模拟程序，该程序计算作为天线几何形状和相对于BO的取向的函数的3D-SNR图。为了找到给定应用的最佳天线设计，该软件将专门用于：1）对常见血管内线圈（例如，环形与相对螺线管线圈）进行正式比较，以及2）通过多种设计的混合组合（例如，通过向相对螺线管线圈添加环形）改变几何结构，研究SNR的可能改善。设计变更需要重新计算SNR图。当比较不同的线圈时，将根据在通过血管和线圈中心的横截面切片中壁的预期位置处计算的最高SNR选择最佳设计。我们将把我们的优化限制在冠状动脉和肾动脉成像线圈上，并使用表面贴装或微加工技术通过模拟确定潜在有用的设计。将在MR体模成像中对所有组装器械进行测试。将在多个方向采集SNR图。将测量的SNR图与模拟数据进行比较，并评价所有制造线圈的模拟精度。最后，将在猪动物模型中对最佳设计进行体内测试。我们预计，该项目将导致SNR优化的导管线圈的识别和原型设计，用于在II期血管疾病动物模型中进行进一步测试。