MRI ANGIOGRAPHY OF HUMAN CORONARY ARTERIES

心血管疾病是美国人死亡的主要原因 每年有超过60万人死于冠状动脉疾病， 每年有超过50万例诊断性心脏导管插入术 在美国，尽管开发了多种非侵入性测试， 心肌缺血的检测，高达20%的诊断冠状动脉 血管造影显示冠状动脉疾病不明显。 冠状 然而，血管造影术伴随着高成本和低，尽管有限， 发病率和死亡率，使其不适合用作筛查 test. 此外，虽然它提供了有关直径的信息， 狭窄，关于冠状动脉血流的定量数据不是 一般可用。 我们最近开发了一种磁共振成像脉冲 允许冠状动脉血液的高分辨率成像的序列 在人类中流动。 完整的图像可以在一次呼吸中获得- 使用商用MR扫描仪和表面线圈保持（10-15秒）。 以来 还可以以< 85毫秒 此外，冠状血管内的血流速度可 现在可以以非侵入性的方式进行评估， 血管内造影剂或血管通路。 我们的目标包括： 1.为了优化MR方法学，以成像人类冠状动脉， 年轻的成年志愿者以及接受诊断性心脏病的患者 冠状动脉造影显示冠状动脉正常的患者 管腔; 2.开发将MR数据处理为投影的方法 血管造影。 将通过与以下对比对MR血管造影片进行确认： 冠状动脉解剖正常患者的常规血管造影 局灶性狭窄者; 3.为了进一步发展MR方法， 绝对冠状动脉血流量，特别是使用相位敏感 结合分段的k空间采集进行成像。 流 定量技术将使用流动模型进行验证， 在计划进行诊断性冠状动脉造影的患者中进行测试， 将使用以下两种方法评估冠状动脉血流 经食管多普勒超声心动图或冠状动脉内多普勒血流 探针; 4.评估冠状动脉血流的变化， 药理学冠状血管舒张。

Cardiovascular disease is the leading cause of death in the United States with over 600,000 deaths per year attributed to coronary artery disease, and over 500,000 diagnostic cardiac catheterizations performed annually in the U.S. Despite the development of multiple noninvasive tests for the detection of myocardial ischemia, up to 20% of diagnostic coronary angiograms reveal insignificant coronary artery disease. Coronary angiography, however, carries with it a high cost and low, though finite morbidity and mortality, making it inappropriate for use as a screening test. Furthermore, while it gives information regarding diameter stenoses, quantitative data regarding coronary blood flow is not generally available. We have recently developed a magnetic resonance (MR) imaging pulse sequence which permits high-resolution imaging of coronary artery blood flow in humans. Complete images may be acquired during a single breath- hold (10-15 sec) using a commercial MR scanner and surface coil. Since images can also be acquired with an effective temporal resolution of < 85 msec. Moreover, blood flow velocities within the coronary vessels can now be assessed in a non-invasive manner and without the need for any intravascular contrast agents or vascular access. Our goals include: 1. To optimize the MR methodology for imaging human coronary arteries in young adult volunteers as well as patients undergoing diagnostic cardiac catheterization in whom coronary angiography reveals normal coronary lumen; 2. To develop the means for processing the MR data into projection angiograms. The MR angiograms will be validated by comparison with conventional angiograms in patients with normal coronary artery anatomy and in those with focal stenoses; 3. To further develop the MR methodology to permit measurement of absolute coronary artery blood flow, specifically using phase-sensitive imaging in conjunction with a segmented k-space acquisition. Flow quantification techniques will be validated using flow phantoms and will be tested in patients scheduled for diagnostic coronary angiography in whom coronary artery blood flow will be assessed using either transesophageal Doppler echocardiography or intracoronary Doppler flow probes; 4. To assess changes in coronary artery blood flow following pharmacologic coronary vasodilation.