Saeed M
Department of Radiology, School of Medicine, University of California, San Francisco 94143-0628, USA.
Exp Biol Med (Maywood). 2001 May;226(5):367-76. doi: 10.1177/153537020122600502.
New concepts regarding the assessment of ischemic myocardial injuries have been addressed in this Minireview using magnetic resonance imaging (MRI). MRI, with its different techniques, brings not only anatomic, but also physiologic, information on ischemic heart disease. It has the ability to measure identical parameters in preclinical and clinical studies. MRI techniques provide the ideal package for repeated and noninvasive assessment of myocardial anatomy, viability, perfusion, and function. MR contrast agents can be applied in a variety of ways to improve MRI sensitivity for detecting and assessing ischemically injured myocardium. With MR contrast agents protocol, it becomes possible to identify ischemic, acutely infarcted, and peri-infarcted myocardium in occlusive and reperfused infarctions. Necrosis specific and nonspecific extracellular contrast-enhanced MRI has been used to assess myocardial viability. Contrast-enhanced perfusion MRI can explore the disturbances in large (angiography) and small coronary arteries (myocardial perfusion) as the underlying cause of myocardial dysfunction. Perfusion MRI has been used to measure myocardial perfusion (ml/min/g) and to demonstrate the difference in transmural myocardial blood flow. Information on no-reflow phenomenon is derived from dynamic changes in regional signal intensity after bolus injection of MR contrast agents. Another development is the near future availability of blood pool MR contrast agents. These agents are able to assess microvascular permeability and integrity and are advantageous in MR angiography (MRA) due to their persistence in the blood. Noncontrast-enhanced MRI such as cine MRI at rest/stress, sodium MRI, and MR spectroscopy also have the potential to noninvasively assess myocardial viability in patients. Futuristic applications for MRI in the heart will focus on identifying coronary artery disease at an early stage and the beneficial effects of new therapeutic agents such as intra-arterial gene therapy. MR techniques will have great future in the drug discovery process and in testing the effects of drugs on myocardial biochemistry, physiology, and morphology. Molecular imaging is going to bloom in this decade.
本综述利用磁共振成像（MRI）探讨了评估缺血性心肌损伤的新概念。MRI凭借其不同技术，不仅能提供缺血性心脏病的解剖学信息，还能提供生理学信息。它能够在临床前和临床研究中测量相同的参数。MRI技术为重复、无创地评估心肌解剖结构、存活能力、灌注和功能提供了理想的组合。磁共振造影剂可以通过多种方式应用，以提高MRI检测和评估缺血性损伤心肌的敏感性。借助磁共振造影剂方案，能够在闭塞性和再灌注性梗死中识别缺血、急性梗死和梗死周边心肌。坏死特异性和非特异性细胞外对比增强MRI已用于评估心肌存活能力。对比增强灌注MRI可以探究大（血管造影）、小冠状动脉（心肌灌注）的紊乱，将其作为心肌功能障碍的潜在原因。灌注MRI已用于测量心肌灌注（毫升/分钟/克），并显示透壁心肌血流的差异。无复流现象的信息来自静脉注射磁共振造影剂后局部信号强度的动态变化。另一个进展是血池磁共振造影剂在不久的将来即可应用。这些造影剂能够评估微血管通透性和完整性，并且由于它们在血液中的持久性，在磁共振血管造影（MRA）中具有优势。非对比增强MRI，如静息/负荷电影MRI、钠MRI和磁共振波谱，也有潜力对患者的心肌存活能力进行无创评估。MRI在心脏领域的未来应用将聚焦于早期识别冠状动脉疾病以及诸如动脉内基因治疗等新型治疗药物的有益效果。MR技术在药物研发过程以及测试药物对心肌生物化学、生理学和形态学的影响方面将有广阔的前景。分子成像将在这十年蓬勃发展。
