Background: Almost intracerebral diseases affect cerebrospinal fluid (CSF) and circulation of CSF in ventricular system and subarachnoid space, including those characterized by changes in the subarachnoid space such as hydrocephalus (HC), arachnoid cyst, Chiari malformation. Objective: Using phase-contrast MRI to quantify the parameters of cerebrospinal flow at the normal ventricle and to compare with HC induced by SAH patients.