British Heart Foundation Experimental MR Unit (BMRU), Department of Cardiovascular Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom.
Magn Reson Med. 2011 Jan;65(1):60-70. doi: 10.1002/mrm.22605.
MRI has become an important tool to noninvasively assess global and regional cardiac function, infarct size, or myocardial blood flow in surgically or genetically modified mouse models of human heart disease. Constraints on scan time due to sensitivity to general anesthesia in hemodynamically compromised mice frequently limit the number of parameters available in one imaging session. Parallel imaging techniques to reduce acquisition times require coil arrays, which are technically challenging to design at ultrahigh magnetic field strengths. This work validates the use of an eight-channel volume phased-array coil for cardiac MRI in mice at 9.4 T. Two- and three-dimensional sequences were combined with parallel imaging techniques and used to quantify global cardiac function, T(1)-relaxation times and infarct sizes. Furthermore, the rapid acquisition of functional cine-data allowed for the first time in mice measurement of left-ventricular peak filling and ejection rates under intravenous infusion of dobutamine. The results demonstrate that a threefold accelerated data acquisition is generally feasible without compromising the accuracy of the results. This strategy may eventually pave the way for routine, multiparametric phenotyping of mouse hearts in vivo within one imaging session of tolerable duration.
MRI 已成为一种重要的工具，可用于非侵入性地评估全球和区域性心脏功能、梗塞面积或心肌血流，适用于人类心脏病的手术或基因修饰的小鼠模型。由于血流动力学受损的小鼠对全身麻醉敏感，因此扫描时间受到限制，这通常限制了在一次成像过程中可用的参数数量。为了缩短采集时间而采用的并行成像技术需要使用线圈阵列，但在超高磁场强度下设计线圈阵列具有技术挑战性。本研究验证了在 9.4T 下使用八通道容积相控阵线圈进行小鼠心脏 MRI 的方法。二维和三维序列与并行成像技术相结合，用于定量评估整体心脏功能、T1 弛豫时间和梗塞面积。此外，快速采集功能电影数据首次允许在静脉输注多巴酚丁胺的情况下测量小鼠左心室峰值充盈和射血率。结果表明，一般来说，三倍加速的数据采集是可行的，而不会影响结果的准确性。该策略最终可能为在可耐受时长的一次成像过程中对活体小鼠心脏进行常规、多参数表型分析铺平道路。
