Using Real Time Phase contrast MRI to investigate CSF oscillations and aqueductal pressure gradients during free breathing

Motivation: CSF dynamics is complex and regulates intracranial pressure. Pressure difference dynamics between the third and fourth ventricles (ΔPt) drives CSF oscillations in the aqueduct. MRI can quantify aqueduct anatomy and CSF oscillations. Goal(s): To quantify ΔPt during free-breathing by combining MRI anatomical imaging with real-time phase-contrast MRI. Approach: We developed a dedicated software to obtain: CSF flows dynamics Q(t), morphology of the aqueduct, its flow resistance (R) and ΔPt which equal R·Qt. Cardiac and breathing contributions to ΔPt were investigated in volunteers. Results: Contributions to ΔPt were 12.3 Pa and 9.5 Pa from cardiac and breathing respectively. Impact: Dedicated post-processing of real-time phase-contrast MRI allows quantification of CSF oscillations in the aqueduct and the pressure gradient between the third and fourth ventricles. Furthermore, continuous flow acquisition allows calculation of the cardiac and breathing influence on the pressure gradient.