Cardiac and respiratory self‐gated cine MRI in the mouse: Comparison between radial and rectilinear techniques at 7T

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. Magn Reson Med 58:745–753, 2007. © 2007 Wiley‐Liss, Inc.