Cassidy Paul J, Schneider Jürgen E, Grieve Stuart M, Lygate Craig, Neubauer Stefan, Clarke Kieran
Oxford Cardiac Research Group Magnetic Resonance Unit, University Laboratory of Physiology, University of Oxford, Oxford, UK.
J Magn Reson Imaging. 2004 Feb;19(2):229-37. doi: 10.1002/jmri.10454.
To assess the performance of motion gating strategies for mouse cardiac magnetic resonance (MR) at high magnetic fields by quantifying the levels of motion artifact observed in images and spectra in vivo.
MR imaging (MRI) of the heart, diaphragm, and liver; MR angiography of the aortic arch; and slice-selective 1H-spectroscopy of the heart were performed on anesthetized C57Bl/6 mice at 11.75 T. Gating signals were derived using a custom-built physiological motion gating device, and the gating strategies considered were no gating, cardiac gating, conventional gating (i.e., blanking during respiration), automatic gating, and user-defined gating. Both automatic and user-defined modes used cardiac and respiratory gating with steady-state maintenance during respiration. Gating performance was assessed by quantifying the levels of motion artifact observed in images and the degree of amplitude and phase stability in spectra.
User-defined gating with steady-state maintenance during respiration gave the best performance for mouse cardiac imaging, angiography, and spectroscopy, with a threefold increase in signal intensity and a sixfold reduction in noise intensity compared to cardiac gating only.
Physiological gating with steady-state maintenance during respiration is essential for mouse cardiac MR at high magnetic fields.
通过量化体内图像和光谱中观察到的运动伪影水平，评估高磁场下小鼠心脏磁共振（MR）运动门控策略的性能。
在11.75T下对麻醉的C57Bl/6小鼠进行心脏、膈肌和肝脏的磁共振成像（MRI）、主动脉弓磁共振血管造影以及心脏的切片选择性1H光谱分析。使用定制的生理运动门控装置获取门控信号，所考虑的门控策略包括无门控、心脏门控、传统门控（即呼吸期间消隐）、自动门控和用户定义门控。自动和用户定义模式均使用心脏和呼吸门控，并在呼吸期间维持稳态。通过量化图像中观察到的运动伪影水平以及光谱中的幅度和相位稳定性程度来评估门控性能。
与仅心脏门控相比，呼吸期间维持稳态的用户定义门控在小鼠心脏成像、血管造影和光谱分析中表现最佳，信号强度增加了三倍，噪声强度降低了六倍。
呼吸期间维持稳态的生理门控对于高磁场下的小鼠心脏MR至关重要。
