PURPOSE: To evaluate the changes in diagnosis of intracranial cerebrospinal fluid (CSF) dynamics in the hydrocephalus, we studied the various parameters of cine phase contrast (PC) magnetic resonance (MR) CSF flow images in cases of acutely progressive hydrocephalus, comparing them with those in normal CSF circulation. MATERIALS AND METHODS: The MR images were obtained with a 1.5T (GE Signa, GE Medical Systems, Milwaukee, USA) unit using the 2 dimensional cine PC sequence with cardiac gating and gradient recalled echo imaging in ten cases of non-obstructive hydrocephalus (NOH), three of obstructive hydrocephalus (OH), and ten controls. The time-echo time-flip angle employed were 50 to 80 msec - 11 to 15 msec - 12 to 15 °. Temporal velocity information relating to cervical pericord CSF spaces, third and fourth ventricles, and the aqueduct were plotted as wave forms which were then analyzed for configuration, amplitude parameters (Vmax, Vmin, Vdif), and temporal parameters (R-S, R-SMV, R-D, R-DMV). The statistical significance of each parameter was examined using the paired t-test. All patients with OH underwent endoscopic third ventriculostomy, whereas all with NOH underwent shunting procedures. RESULTS: In five ROIs, distinct reproducible configuration features were obtained at aqueduct and cervical pericord spaces, but not at ventricular levels. We determined the statistically significant differences between controls and hydrocephalus patients using temporal, rather than amplitude parameters. In NOH, the graph showed R-DMV shortening (p<0.01) at the anterior cervical pericord space. In OH, there were R-DMV shortening (p<0.05) was seen at the anterior cervical pericord space, and R-DMV shortening (p<0.02) at the posterior cervical pericord space. In one case of OH, a typical change of configuration, mirror image, was obtained at aqueduct level, and in all OH cases, the level of obstruction could be determined. CONCLUSION: The results of cine PC MR CSF flow study may be valuable for points for determining the level of obstruction, explaining the cause of hydrocephalus, diagnosing OH, and deciding the need for shunting procedures; decisions would be based on an analysis of in vivo images, curve configuration, and phase shift of the velocity curve. In the diagnosis of acutely progressive hydrocephalus, termporal parameters are nore important than those relating to amplitude. Among the former, R-DMV and/or R-SMV may be the most valuable.