MRI-Guided Angioplasty of Coronary Artery Stenosis

描述(由申请人提供)： 这项建议的广泛、长期目标是改善冠心病患者的预后。我们建议使用磁共振成像(MRI)来指导经皮冠状动脉腔内成形术(PTA)，并测量PTA对心肌灌注的影响。与传统的X光引导下冠状动脉PTA相比，MRI有几个潜在的优势。MRI不需要使用有肾毒性和过敏反应风险的碘化造影剂。这一优势对肾功能不佳的患者尤为重要。核磁共振成像可以直接监测PTA时心脏灌注的变化，这一能力可以导致预期治疗的变化，并可能预测治疗的成功。与X光不同，核磁共振不需要使用电离辐射，因为电离辐射可能会对患者造成伤害。此外，手术医生和医院工作人员可以通过避免终身电离辐射暴露的累积影响而大大受益。该项目的具体目标是使用幻影和犬模型来验证以下假设：具体目标1：MRI可以达到用于设备跟踪的帧速率和空间分辨率，以及用于指导冠状动脉PTA的路线图获取。具体目的2：基于导管的诊断冠状动脉磁共振血管成像准确地显示冠状动脉狭窄。具体目的3：MRI和X光引导下经皮冠状动脉腔内成形术治疗犬冠状动脉狭窄的技术成功率相似。具体目标4：MRI引导下成功的冠状动脉狭窄经皮冠状动脉腔内成形术(PTA)改善了手术时MRI测量的心肌血流灌注。该项目的圆满完成将为进一步的技术改进奠定基础。在获得更多经验后，我们预计将转向MIRI指导冠状动脉介入治疗，因为它有能力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.