MRI evaluation of acute cardiovascular disease

今年是NIH郊区MRI中心的第一个整年。 该计划使我们的研究能够接触到有急性心血管疾病症状的患者。研究计划的总体目的仍然是：1）开发心血管MRI应用和分析，2）心肌灌注、收缩功能和心肌活力的生理学评估，3）心血管疾病的临床评价，重点是心肌缺血和缺血性心脏病。在过去的一年中，MR图像采集的进展包括一种新的高分辨率对比增强扫描，该扫描在造影剂给药后10-30分钟将心肌梗死描绘为图像上的亮点。 在今年完成的动物研究中，MRI对梗死面积的估计与病理证实之间存在密切相关性。 在患者研究中，该方法似乎对陈旧性和新发心肌梗死具有非常高的灵敏度。 它为胸痛患者的急诊室分诊增加了重要的力量。 关于可逆性心肌损伤的特异性仍然存在问题。 该方法适用于接受室间隔酒精消融术的肥厚型心肌病患者。 成像方面的其他进展包括更快的方法，现在可以以每张图像31 ms的时间分辨率对左心室功能进行成像。 该方法可以定量测量与自行车运动相关的心肌射血分数变化，而无需ECG门控或屏气。 一种新的成像技术已经开发出来，以提高血池和心肌梗死区域之间的对比度。 由于与郊区医院的合作，梗塞成像工作在很大程度上得到了完善。 一项使用这些新的成像技术评估急诊室胸痛患者的初步研究表明，MRI能够检测心肌损伤，其灵敏度与连续肌钙蛋白测量相当。 在少数情况下，MRI在血液测试超过正常限度之前就已经检测到异常。 虽然技术进步继续以快速的步伐，现有的MRI方法似乎相当有前途的患者与冠状动脉疾病。

This year represents the first full year of the NIH-Suburban MRI Center. This program has opened our research significantly with access to patients with symptoms of acute cardiovascular disease. The overall purposes of the research program remain: 1) development of cardiovascular MRI applications and analysis, 2) physiological assessment of myocardial perfusion, contractile function and myocardial viability, and 3) clinical evaluation of cardiovascular disease with an emphasis on myocardial ischemia and ischemic heart disease. Advances in MR image acquisition during the past year include a new high-resolution contrast enhanced scan that delineates myocardial infarction as a bright spot on images 10-30 minute after contrast administration. In animal studies completed this year, there is a tight correlation between MRI estimates of infarct size and pathological confirmation. In patient studies, this method appears to have very high sensitivity for old and new myocardial infarctions. It adds significant power to the emergency room triage of patients with chest pain. Issues remain regarding the specificity for reversible myocardial injury. This method is applicable to patients with hypertrophic cardiomyopathy undergoing alcohol ablation of the interventricular septum. Other advances in imaging include faster approaches that can now image left ventricular function with a temporal resolution of 31 ms per image. This method can quantitatively measure myocardial ejection fraction changes associated with bicycle exercise without the need for ECG gating or a breathhold. A new imaging technique has been developed to improve the contrast between the blood pool and the area of myocardial infarction. The infarct imaging work was largely perfected as a result of the collaboration with Suburban Hospital. A pilot study using these new imaging techniques to assess patients with chest pain in the emergency room suggests MRI is able to detect myocardial injury with comparable sensitivity to serial troponin measurements. In a few cases, the MRI has detected abnormalities before the blood test exceeded the normal limits. Although technical advances continue at a rapid pace, existing MRI methods appear quite promising in patients with coronary artery disease.