Detection of Coronary Stenoses Using T2-Weighted MRI

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)通过使用T2加权技术评估心肌T2改变来检测临床上有意义的冠状动脉狭窄的存在。长期目标是确定那些有缺血性心脏病风险的患者，他们可能受益于血管干预，如经皮血管腔内成形术或搭桥术。在拟议的项目中，将使用受控良好的动物模型(狗)。会造成不同程度的冠状动脉狭窄。这些研究将在最先进的3-特斯拉成像系统上进行，以提高测试的灵敏度。与传统的首次通过对比剂增强心肌灌注评价方法相比，该方法具有不需要药物负荷试验和/或更好的空间分辨率和覆盖率的优点。该项目的具体目标是：目标1：开发一种用于心脏T2测量的T2三维稳态进动真快速成像技术，并在体模上验证MR血容量分数的测量。目的2：验证冠状动脉内直接注射腺苷后局部心肌T2差值在3.0T时大于1.5T时。目的3：验证静息状态下磁共振T2加权成像能否发现有意义的冠状动脉狭窄供血区域。目的4：测试磁共振T2加权成像是否能检测到药物应激下血流储备的2倍区域差异。该项目的积极结果将保证在患者中进行临床研究，以评估T2加权磁共振成像在检测重要的功能性冠状动脉疾病中的作用。

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 detect the presence of clinically significant coronary artery stenoses by assessing the myocardial T2 changes using a T2-weighted technique. The long term goal is to identify those patients at risk of ischemic heart disease who might benefit from vascular interventions such as percutaneous transluminal angioplasty or bypass graft. In the proposed project, a well-controlled animal model (dog) will be used. Various levels of coronary artery stenoses will be created. The studies will be performed on a state-of-the-art 3-Tesla imaging system to improve the sensitivity of the test. Compared to the conventional method of myocardial perfusion evaluation using first-pass contrast-enhanced technique, the proposed method has the advantage of potentially not requiring pharmacological stress test, and/or better spatial resolution and coverage. The specific aims of the proposed project are: Aim 1: To develop a T2-prepared three-dimensional true fast imaging with steady state precession technique for T2 measurement in the heart and to validate MR blood volume fraction measurement on phantom. Aim 2: To verify that regional myocardial T2 difference following direct adenosine injection into the coronary artery is greater at 3.0 T than that at 1.5 T. Aim 3: To test whether territory supplied by functionally significant coronary artery stenoses can be detected using T2-weighted MR imaging under resting conditions. Aim 4: To test whether MR T2-weighted imaging can detect a 2-fold regional difference in blood flow reserve under pharmacologic stress. Positive results from this project will warrant clinical studies in patients to evaluate the role of T2-weighted MR imaging in detecting functionally significant coronary artery disease.