Cardiac-respiratory gating method for magnetic resonance imaging of the heart

In studies of transmural myocardial function, acquisitions of high spatial and temporal resolution tagged cardiac images often exceed the practical ti me limit for breath-hold fast imaging techniques. Therefore, a dual cardiac -respiratory gating device has been constructed to acquire SPAMM-tagged car diac MR images at or near end-expiration during spontaneous breathing, by p roviding an external trigger to a conventional MRI system. Combined cardiac and respiratory gating essentially eliminates the respiratory motion artif acts in tagged cardiac MR images. Compared to cardiac-gated images obtained during intermittent breath-holds, cardiac-respiratory gated images show im proved tag-myocardium contrast due to magnetization recovery during inspira tion. (C) 2000 Wiley-Liss, Inc.