Normal and abnormal cerebrospinal fluid dynamics evaluated by optimized cine phase-contrast MR imaging

To evaluate the normal and abnormal cerebrospinal fluid (CSF) hydrodynamics by quantitatively measuring the peak velocity of CSF in the aqueduct using two-dimensional cine phase-contrast magnetic resonance (MR) imaging. A prospective CSF flow study was performed with the use of an optimized two-dimensional cine phase-contrast MR technique. Ten normal age-matched volunteers (mean age 58.5 years) and 20 patients with abnormal CSF hydrodynamics were enrolled. The patient groups include 16 normal pressure hydrocephalus (NPH) cases (mean age 69.2 years) and four with communicating hydrocephalus (CH) (mean age 38.5 years). All images were acquired on both sagittal and axial planes using a bipolar gradient pulse sequence on a 1.5-tesla scanner (Siemens Vision+, Erlangen, Germany). The mean maximum CSF flow velocities (Vmax) at the aqueduct were 4.93 ± 0.28 cm/s (mean ± SD) for the control group, and 6.22 ± 0.67 and 7.24 ± 1.08 cm/s for the NPH and CH groups, respectively. The NPH group could be further divided into hyper- and hypodynamic groups when compared with the normal age-matched subjects. Vmax of the control group was significantly higher than that of the hypodynamic-NPH group (1.92 ± 1.11 cm/s, p < 0.001) and lower than that of the CH group (p < 0.007) and of the hyperdynamic-NPH group (10.52 ± 0.23 cm/s, p < 0.001). With optimized parametric setting, two-dimensional cine phase-contrast MR imaging appears to be practical for routine evaluation of patients with abnormal CSF flow dynamics. The peak velocity of the CSF flow was significantly higher in the hyperdynamic-NPH group but lower in the hypodynamic-NPH group as compared with the control group. Our results confirm that, in NPH patients, a pre-surgical MR imaging evaluation of CSF potentially can be very helpful in distinguishing the low-CSF-dynamic from high-CSF-dynamic groups before any CSF diversion procedure is contemplated.