Quantitative phase-contrast MRI study of cerebrospinal fluid flow: a method for identifying patients with normal-pressure hydrocephalus.

OBJECTIVES The aim of this study is to evaluate the use of phase-contrast MR imaging to diagnose normal pressure hydrocephalus (NPH) and differentiate it from other neurological disorders with similar clinical symptoms. METHODS The study included 108 subjects, of whom 61 were healthy controls and 47, patients; in the patient group, 19 had cerebrovascular disease (CVD) and 28 had NPH. All patients underwent a phase-contrast MRI study and several CSF flow and velocity parameters were measured at the aqueduct of Sylvius. Discriminant analyses were performed to evaluate the classification capacity of both individual parameters and the combination of different parameters. RESULTS Maximum diastolic velocity, mean flow, and stroke volume showed statistically significant differences that could be used to distinguish between NPH and CVD patients (P<.001). Stroke volume and mean flow showed no false positive results and successful classification rates of 86% and 79%, respectively. No other parameters or combination produced better results. CONCLUSIONS Phase-contrast MR imaging is a useful tool for the early diagnosis of patients with NPH. CSF flow quantitative parameters, along with morphological features in a conventional MR study, enable us to differentiate between NPH and CVD patients.