Department of Biomedical Engineering, University of Virginia, Charlottesville, Virginia 22908, USA.
Magn Reson Med. 2010 Mar;63(3):648-57. doi: 10.1002/mrm.22280.
Experimental myocardial infarction (MI) in mice is an important disease model, in part due to the ability to study genetic manipulations. MRI has been used to assess cardiac structural and functional changes after MI in mice, but changes in myocardial perfusion after acute MI have not previously been examined. Arterial spin labeling noninvasively measures perfusion but is sensitive to respiratory motion and heart rate variability and is difficult to apply after acute MI in mice. To account for these factors, a cardiorespiratory-gated arterial spin labeling sequence using a fuzzy C-means algorithm to retrospectively reconstruct images was developed. Using this method, myocardial perfusion was measured in remote and infarcted regions at 1, 7, 14, and 28 days post-MI. Baseline perfusion was 4.9 +/- 0.5 mL/g min and 1 day post-MI decreased to 0.9 +/- 0.8 mL/g min in infarcted myocardium (P < 0.05 versus baseline) while remaining at 5.2 +/- 0.8 mL/g min in remote myocardium. During the subsequent 28 days, perfusion in the remote zone remained unchanged, while a partial recovery of perfusion in the infarct zone was seen. This technique, when applied to genetically engineered mice, will allow for the investigation of the roles of specific genes in myocardial perfusion during infarct healing.
实验性心肌梗死（MI）在小鼠中是一种重要的疾病模型，部分原因是能够研究基因操作。MRI 已被用于评估 MI 后小鼠的心脏结构和功能变化，但以前尚未检查过急性 MI 后心肌灌注的变化。动脉自旋标记非侵入性地测量灌注，但对呼吸运动和心率变异性敏感，并且在 MI 后难以在小鼠中应用。为了考虑这些因素，开发了一种使用模糊 C 均值算法进行回顾性图像重建的心脏呼吸门控动脉自旋标记序列。使用该方法，在 MI 后 1、7、14 和 28 天测量了远程和梗死区域的心肌灌注。基础灌注为 4.9 +/- 0.5 mL/g min，MI 后 1 天降低至梗死心肌的 0.9 +/- 0.8 mL/g min（与基线相比，P < 0.05），而在远程心肌中仍为 5.2 +/- 0.8 mL/g min。在随后的 28 天中，远程区域的灌注保持不变，而梗死区域的灌注部分恢复。当应用于基因工程小鼠时，该技术将允许研究特定基因在梗死愈合过程中对心肌灌注的作用。
