Real Time Phase Contrast MRI and Cerebrovascular Beat-to-Beat Variability Changes with Respiration Mode

Real-time, phase-contrast MRI (RT-PC-MRI) provides a quantitative evaluation of flow signals. Focusing the high cervical level, the fluid interchange of the intracranial compartment can thus be monitored. In the present study we address the beat-to-beat variability of the arterial, venous, and liquor flows in 30 healthy volunteers. Also, the median beats in the inspiratory and expiratory phases are derived, considering three respiratory conditions: free, paced, and deep. These results, though preliminary, clearly demonstrate the utility of this new technique.