Magnetic Resonance Imaging Evaluation of Acute Cardiovascular Disease

心肌灌注成像仍然是该组织感兴趣的领域。今年完成了对25名正常人和25名冠心病患者的临床研究。本研究表明潘生丁负荷MRI研究对冠状动脉疾病的检测具有临床相关的敏感性和特异性。这种方法似乎是第一个临床上可用的方法，能够常规区分心内膜异位症和心外膜灌注异常。肥厚型心肌病患者也有局限于内膜的灌注异常。在受试者明显的左心室腔扩张铊，MRI灌注异常主要是endoerythrocyte在最严重的肥厚区域，而不是弥漫性分布。完成了一项比较MRI和荧光微球测定心肌血流量的验证研究。在造影剂到达后的固定时间间隔处的心肌对比增强率与内膜下微球测量在空间上和相对灌注方面都有很好的相关性。使用与加速MRI灌注成像相同的原理开发了更快的电影MRI应用程序。今年的一项技术研究描述了使用短分段回波平面读数来提高电影MRI（磁共振成像）效率的原理。第二个技术研究的特点，这种方法的成像参数的优化。这些研究表明，在1.5特斯拉下，心脏成像存在最佳读出持续时间。一方面，读出持续时间受信噪比和扫描效率的限制。在较长的读出持续时间，血流相关的伪影和几何失真占主导地位。这些快速成像方法的经验使我们能够通过实时成像获取心脏的体积数据，并在自行车运动后立即冻结心脏运动。我们正在研究与动脉粥样硬化相关的血管炎症。我们开发了一种旨在检测血管壁炎症的MRI方法。我们还确定了肥厚型心肌病患者的肥厚心肌是一个三维螺旋。- 磁共振成像，缺血性心脏病，心肌缺血，心肌梗死，心肌灌注，动脉粥样硬化-人类受试者

Myocardial perfusion imaging continues to be an area of interest for the group. A clinical study of 25 normal subjects and 25 patients with coronary artery disease was completed this year. This study indicated the dipyridamole stress MRI studies have clinically relevant sensitivity and specificity for detection of coronary artery disease. This methodology appears to be the first clinically available approach capable of routinely differentiating endocardial from epicardial perfusion abnormalities. Patients with hypertrophic cardiomyopathy also have perfusion abnormalities that localize to the endocardium. In subjects with apparent left ventricular cavity dilatation on thallium, the MRI perfusion abnormality is primarily endocardial in the most severely hypertrophic regions rather than diffusely distributed. A validation study was completed comparing myocardial blood flow determinations by MRI and fluorescent microspheres. Myocardial contrast enhancement ratio at a fixed time interval after contrast arrival correlates well with subendocardial microsphere measurements both spatially and in terms of relative perfusion. Faster cine MRI applications have been developed using the same principles developed to accelerate MRI perfusion imaging. One technical study this year describes the principle of using short segmented echoplanar readouts to increase the efficiency of cine MRI (magnetic resonance imaging). A second technical study characterizes the optimization of imaging parameters for this methodology. These studies indicate that there is an optimal readout duration for cardiac imaging at 1.5 Tesla. On one side readout duration is bounded by signal-to-noise and scan efficiency. At longer readout durations, blood flow related artifacts and geometric distortion dominate. Experience with these faster imaging methods has allowed us to acquire volumetric data of the heart with real-time imaging and to freeze cardiac motion in immediately after bicycle exercise. We are studying vascular inflammation associated with atherosclerosis. We developed an MRI methodology designed to detect inflammation in the vascular wall. We have also determined that hypertrophic myocardium in some patients with hypertrophic cardiomyopathy is in a 3-dimensional spiral. - Magnetic resonance imaging, ischemic heart disease, myocardial ischemia, myocardial infarction, myocardial perfusion, atherosclerosis - Human Subjects