Two-dimensional cine phase contrast (2D-cine PC) magnetic resonance (MR) imaging is an imaging technique that sensitizes MR images to velocity changes in a specific direction while cancelling signals from stationary protons and from motion in other directions. This article reviews the technique, conventions, and applications of this imaging technique to hydrocephalus. 2D-Cine PC and additional more rapid MR imaging methods now in development will allow clinicians to measure CSF velocity, pulsation, and bulk flow noninvasively in normal individuals and in patients with a variety of pathologic conditions. It is hoped that these measurements may be correlated with intracranial pressures to develop clinical tests of brain compliance and improved management of patients with hydrocephalus.