Detection of Coronary Stenoses Using T2-Weighted MRI

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），以检测临床上显着的冠状动脉狭窄的存在，通过评估心肌T2的变化，使用T2加权技术。长期目标是确定那些有缺血性心脏病风险的患者，他们可能从血管介入治疗（如经皮腔内血管成形术或旁路移植术）中获益。在拟定项目中，将使用控制良好的动物模型（犬）。将产生不同程度的冠状动脉狭窄。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。与使用首过对比增强技术的心肌灌注评价的传统方法相比，所提出的方法具有潜在地不需要药理学负荷测试和/或更好的空间分辨率和覆盖范围的优点。拟议项目的具体目标是：目标1：开发一种用于心脏T2测量的T2准备三维真快速成像（采用稳态进动技术），并验证体模上的MR血容量分数测量。目标二：验证腺苷直接注入冠状动脉后，在3.0 T下的局部心肌T2差大于1.5 T下的局部心肌T2差。目标3：旨在测试在静息条件下使用T2加权MR成像是否可以检测到由功能显著的冠状动脉狭窄提供的区域。目的4：测试磁共振T2加权成像是否可以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，以评价T2加权MR成像在检测功能显著的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.