Hiba Bassem, Richard Nathalie, Thibault Hélène, Janier Marc
ANIMAGE, Rhône-Alpes Genopole, Université Claude Bernard Lyon1, Lyon, France.
Magn Reson Med. 2007 Oct;58(4):745-53. doi: 10.1002/mrm.21355.
ECG-gated cardiac MRI in the mouse is hindered by many technical difficulties in ECG signal recording inside high magnetic field scanners. The present study proposes a robust rectilinear method of acquiring cardiac and respiratory self-gated cine images in mouse hearts. In this approach, a motion-synchronization MR signal is collected in the center of k-space simultaneously with imaging data in each readout of a nontriggered rectilinear acquisition. This signal is then used for both cardiac and respiratory retrospective gating before cine image reconstruction. The value of this approach for overcoming ECG-gating failure was demonstrated by performing cardiac imaging in eight mice with myocardial infarction. Comparison with an auto-gated radial k-space sampling technique, previously reported for cardiac applications in the mouse, found the rectilinear strategy more robust, thanks to a more reliable self-gating signal, while the radial strategy was less sensitive to motion and flow artifacts.
在高磁场扫描仪内记录心电图信号时存在诸多技术难题，这阻碍了小鼠心电图门控心脏磁共振成像（ECG - gated cardiac MRI）的发展。本研究提出了一种稳健的直线采集方法，用于获取小鼠心脏的心脏和呼吸自门控电影图像。在这种方法中，在非触发直线采集成像数据的每次读出过程中，于k空间中心同时采集运动同步磁共振信号。然后，该信号在电影图像重建前用于心脏和呼吸回顾性门控。通过对八只患有心肌梗死的小鼠进行心脏成像，证明了该方法在克服心电图门控失败方面的价值。与先前报道的用于小鼠心脏应用的自动门控径向k空间采样技术相比，直线策略更稳健，这得益于更可靠的自门控信号，而径向策略对运动和流动伪影不太敏感。
