Hiba Bassem, Richard Nathalie, Janier Marc, Croisille Pierre
Platform ANIMAGE, Rhône-Alpes Genopole, Lyon, France.
Magn Reson Med. 2006 Mar;55(3):506-13. doi: 10.1002/mrm.20815.
ECG-gated cardiac MRI in the mouse is hindered by many technical difficulties in ECG signal recording inside static and variable high magnetic scanner fields. The present study proposes an alternative robust method of acquiring auto-gated cardiac and respiratory cine images in mouse heart. In our approach, a motion synchronization signal is extracted from the echo peak MR signal of a non-triggered radial acquisition. This signal is then used for both cardiac and respiratory retrospective gating before cine image reconstruction. Highly asymmetric echoes were acquired to achieve the radial k-space sampling in order to avoid radial acquisition related artifacts and to increase auto-gating robustness. In vivo experiments demonstrated the feasibility and robustness of self-gated cine-MRI in the mouse heart at 7T. The signal-to-noise and contrast-to-noise ratios of the self-gated and ECG-gated images were comparable, all parameters being equal. Magn Reson Med, 2006. (c) 2006 Wiley-Liss, Inc.
在静态和可变高磁场扫描仪场中记录心电图（ECG）信号存在诸多技术难题，这阻碍了小鼠的心电图门控心脏磁共振成像（MRI）。本研究提出了一种在小鼠心脏中获取自动门控心脏和呼吸电影图像的可靠替代方法。在我们的方法中，从非触发径向采集的回波峰值磁共振信号中提取运动同步信号。然后，该信号在电影图像重建之前用于心脏和呼吸回顾性门控。采集高度不对称回波以实现径向k空间采样，从而避免与径向采集相关的伪影并提高自动门控的稳健性。体内实验证明了在7T场强下小鼠心脏自门控电影MRI的可行性和稳健性。在所有参数相同的情况下，自门控图像和心电图门控图像的信噪比和对比噪声比相当。《磁共振医学》，2006年。（c）2006威利 - 利斯公司。
