Faculty of Medicine, University of Geneva, Geneva, Switzerland.
NMR Biomed. 2010 Jun;23(5):503-13. doi: 10.1002/nbm.1489.
Manganese (Mn(2+)) was recognized early as an efficient intracellular MR contrast agent to assess cardiomyocyte viability. It had previously been used for the assessment of myocardial infarction in various animal models from pig to mouse. However, whether Manganese-Enhanced MRI (MEMRI) is also able to assess infarction in the acute phase of a coronary occlusion reperfusion model in mice has not yet been demonstrated. This model is of particular interest as it is closer to the situation encountered in the clinical setting. This study aimed to measure infarction volume taking TTC staining as a gold standard, as well as global and regional function before and after Mn(2+) injection using a clinical 3T scanner. The first step of this study was to perform a dose-response curve in order to optimize the injection protocol. Infarction volume measured with MEMRI was strongly correlated to TTC staining. Ejection fraction (EF) and percent wall thickening measurements allowed evaluation of global and regional function. While EF must be measured before Mn(2+) injection to avoid bias introduced by the reduction of contrast in cine images, percent wall thickening can be measured either before or after Mn(2+) injection and depicts accurately infarct related contraction deficit. This study is the first step for further longitudinal studies of cardiac disease in mice on a clinical 3T scanner, a widely available platform.
锰（Mn(2+)）很早就被认为是一种有效的细胞内磁共振对比剂，用于评估心肌细胞活力。它以前曾被用于各种动物模型（从猪到老鼠）的心肌梗死评估。然而，锰增强磁共振成像（MEMRI）是否也能够评估冠状动脉闭塞再灌注模型中急性心肌梗死尚未得到证实。这种模型特别有趣，因为它更接近临床环境中遇到的情况。本研究旨在使用临床 3T 扫描仪，以 TTC 染色作为金标准，测量梗塞体积，以及 Mn(2+)注射前后的整体和局部功能。本研究的第一步是进行剂量反应曲线，以优化注射方案。MEMRI 测量的梗塞体积与 TTC 染色有很强的相关性。射血分数（EF）和壁增厚百分比测量可用于评估整体和局部功能。虽然 EF 必须在 Mn(2+)注射前测量，以避免电影图像对比度降低带来的偏差，但壁增厚百分比可以在 Mn(2+)注射前后测量，准确描绘梗塞相关的收缩缺陷。本研究是在临床 3T 扫描仪上对老鼠进行心脏疾病进一步纵向研究的第一步，这是一个广泛应用的平台。
