Methods for MR Guided Interventions in Coronary Vessels

描述（由申请人提供）：冠状血管中MRI引导介入的方法。MRI可以提供评估血管和软组织形态和功能的手段。为此，有可能将联合收割机血管介入MR方法与MR诊断方法相结合，以提供单一模态的综合测试。这种综合测试不仅可以诊断疾病，还可以指导干预程序并评估干预结果。这种能力可以促进新的治疗方法，并可能改善对血管疾病（包括冠状动脉疾病）患者的管理。本提案的目的首先是开发和实施适用于MR引导冠状动脉介入治疗的MRI技术，其次是评估在冠状动脉中进行MR引导介入治疗的可行性。所提出的方法的中心原理是通过冠状动脉内灌注MR造影剂来产生血管造影增强。本提案的目的将通过对内固定犬进行计算机模拟、体模研究和体内研究来解决。我们将追求四个具体目标。(a)开发和优化MR技术，包括脉冲序列和RF线圈，用于冠状动脉的动态近实时多层成像，基于通过冠状动脉内灌注MR造影剂、底层组织饱和和外部体积抑制减少视野的对比度增强血管。(b)建立低剂量MR造影剂冠状动脉内输注方案，即输注浓度、体积和持续时间，适用于同一手术期间的多次动态冠状动脉MR血管造影术。(c)开发被动可视化方法，以成像并区分造影剂填充的介入导管与造影剂增强的冠状动脉血管，用于使用MRI指导冠状动脉内手术。为此，将对双腔和双同轴经皮腔内冠状动脉成形术（PTCA）球囊导管组装件进行研究。（d）评估在分级生成的狭窄的犬模型上执行MR引导球囊PTCA的可行性，以通过狭窄远端心肌的对比增强首过灌注成像来评估干预的结果。

DESCRIPTION (provided by applicant):Methods for MRI Guided Interventions in Coronary Vessels. MRI can provide the means to assess both vascular and soft tissue morphology and function. For this reason, it is possible to combine vascular interventional MR methods with MR diagnostic methods to provide a single-modality comprehensive test. This combined test would not only diagnose disease, but would also guide interventional procedures and assess the results of intervention. Such capabilities could facilitate new therapeutic approaches and may result in improved management of patients with vascular disease, including coronary artery disease. The objectives of this proposal are first, to develop and implement MRI techniques suitable for MR-guided coronary interventions, and second, to assess the feasibility of performing MR-guided interventions in the coronary arteries. The central principle of the proposed approach is the generation of vascular contrast enhancement by intracoronary infusion of MR contrast agent. The objectives of this proposal will be addressed by performing computer simulations, phantom studies and in vivo studies on instrumented canines. We will pursue four specific aims. (a) Develop and optimize MR techniques, that include pulse sequences and RF coils, for dynamic near-real time multislice imaging of the coronary arteries, based on contrast-enhanced vessel by intracoronary infusion of MR contrast agent, saturation of the underlying tissue and reduction of the field-of-view with outer volume suppression. (b) Establish low-dose MR contrast agent intracoronary infusion protocols, i.e. concentration, volume, and duration of infusion, suitable for multiple dynamic coronary MR-angiography sessions during the same procedure. (c) Develop passive visualization approaches to image and differentiate contrast agent-filled interventional catheters from contrast enhanced coronary vessels, for guiding intracoronary procedures with MRI. Dual lumen and dual-coaxial percutaneous transluminal coronary angioplasty (PTCA) balloon catheter assemblies will be investigated for that purpose. (d)Assess the feasibility of performing MR-guided balloon PTCA on a canine model of graded generated stenosis to assess the results of the intervention via contrast-enhanced first pass perfusion imaging of the myocardium distal to the stenosis.