MRI-Guided Angioplasty of Coronary Artery Stenosis

描述（由申请人提供）： 该提案的广泛、长期目标是改善冠状动脉疾病患者的预后。我们建议使用磁共振成像（MRI）引导冠状动脉经皮腔内血管成形术（PTA），并测量PTA对心肌灌注的影响。MRI在冠状动脉PTA中具有优于传统X线引导的几个潜在优势。MRI不需要使用碘化造影剂，碘化造影剂有肾毒性和过敏反应的风险。这一优势对于肾功能不佳的患者尤其重要。MRI允许在PTA时直接监测心脏灌注的变化，这种能力可以导致预期治疗的变化，并可以预测治疗的成功。与X射线不同，MRI不需要使用可能伤害患者的电离辐射。此外，手术医生和医院工作人员可以大大受益于避免电离辐射暴露的终身累积效应。本项目的具体目标是使用体模和犬模型来测试以下假设：具体目标1：MRI可以实现用于引导冠状动脉PTA的器械跟踪和路线图采集的帧率和空间分辨率。具体目标2：基于导管的诊断性冠状动脉MR血管造影准确显示冠状动脉狭窄。特定目的3：MRI和X线引导PTA治疗犬冠状动脉狭窄的技术成功率相似。特定目的4：成功的MRI引导下冠状动脉狭窄PTA改善了手术时MRI测量的心肌灌注。该项目的成功完成将为进一步的技术改进奠定基础。在获得更多的经验后，我们预计将转向MIRI指导冠状动脉介入治疗，因为它能够在介入治疗时进行准确的功能评估。

DESCRIPTION (provided by applicant): The broad, long-term objective of this proposal is to improve the prognosis of patients with coronary artery disease. We propose to use magnetic resonance imaging (MRI) to guide percutaneous transluminal angioplasty (PTA) of coronary arteries and to measure the effect of PTA on myocardial perfusion. MRI has several potential advantages over conventional x-ray guidance for coronary PTA. MRI does not require the use of iodinated contrast medium, which has risks of renal toxicity and allergic reaction. This advantage is especially important to patients with poor kidney function. MRI permits direct monitoring of changes in cardiac perfusion at the time of PTA, a capability that can lead to changes in the anticipated treatment and may predict the success of the therapy. Unlike x-ray, MRI does not require the use of ionizing radiation, which can harm the patient. Additionally, the operating physician and hospital staff can benefit greatly by avoiding the cumulative effects of a lifetime of ionizing radiation exposure. The specific aims of the project are to use phantoms and canine models to test the following hypotheses: Specific Aim 1: MRI can achieve the frame rate and spatial resolution for device tracking and roadmap acquisition for guiding coronary PTA. Specific Aim 2: Catheter-based diagnostic coronary MR angiography accurately depicts coronary artery stenoses. Specific Aim 3: The technical success rates for MRI- and x-ray-guided PTA of coronary artery stenoses in canines are similar. Specific Aim 4: Successful MRI-guided PTA of coronary artery stenoses improves myocardial perfusion as measured with MRI at the time of the procedure. Successful completion of the project will serve as the foundation for further technical improvements. After more experience is gained, we anticipate a shift towards MIRI guidance for coronary interventions because of its capability to perform accurate functional assessment at the time of the intervention.