Late Gadolinium-Enhancement Cardiac Magnetic Resonance Identifies Postinfarction Myocardial Fibrosis and the Border Zone at the Near Cellular Level in Ex Vivo Rat Heart

作者：Erik B. Schelbert, Li‐Yueh Hsu, Stasia A. Anderson, Bibhu D. Mohanty, Syed M. Karim, Peter Kellman, Anthony H. Aletras, Andrew E. Arai · 发表于：Circulation Cardiovascular Imaging · 年份：2010 · DOI：10.1161/circimaging.108.835793 · 被引用次数：175 · 研究领域：Cardiac Imaging and Diagnostics、Advanced MRI Techniques and Applications、Cardiac Fibrosis and Remodeling

BACKGROUND: using a resolution 1000-fold higher than prior studies, we studied (1) the degree to which late gadolinium-enhancement (LGE) cardiac magnetic resonance tracks fibrosis from chronic myocardial infarction and (2) the relationship between intermediate signal intensity and partial volume averaging at distinct "smooth" infarct borders versus disorganized mixtures of fibrosis and viable cardiomyocytes. METHODS AND RESULTS: sprague-Dawley rats underwent myocardial infarction by coronary ligation. Two months later, rats were euthanized 10 minutes after administration of 0.3 mmol/kg intravenous gadolinium. LGE images ex vivo at 7 T with a 3D gradient echo sequence with 50×50×50 μm voxels were compared with histological sections (Masson trichrome). Planimetered histological and LGE regions of fibrosis correlated well (y=1.01x-0.01; R(2)=0.96; P<0.001). In addition, LGE images routinely detected clefts of viable cardiomyocytes 2 to 4 cells thick that separated bands of fibrous tissue. Although LGE clearly detected disorganized mixtures of fibrosis and viable cardiomyocytes characterized by intermediate signal intensity voxels, the percentage of apparent intermediate signal intensity myocardium increased significantly (P<0.01) when image resolution was degraded to resemble clinical resolution consistent with significant partial volume averaging. CONCLUSIONS: these data provide important validation of LGE at nearly the cellular level for detection of fibrosis after myocardial ...