The intracranial volume is made up by the cerebrospinal fluid (CSF) volume, the blood flow volume and the brain parenchyma.The inflow blood to the skull in systole temporary increases the intracranial volume.According to the Monroe-Kellie doctrine an increase in one volume should cause a decrease in one or both of the remaining two volumes in order to maintain volume constant.The imbalances that occur in this process of cerebral homeostasis have been linked to neurodegenerative and cerebrovascular diseases.Therefore, adequate methodologies in order to analyze the dynamic of the intracranial fluids (LCR and blood) are necessary.The cine sequences of phase contrast magnetic resonance imaging (PC-MRI) with cardiac synchronism allow to quantify the CSF and blood flows during a cardiac cycle.Flow measurement with PC-MRI is accurate and reproducible if an adequate acquisition protocol is used.The reproducibility and accuracy of the