[Normal values for cerebrospinal fluid flow dynamics in the aqueduct of Sylvius through optimized analysis of...

To establish normal values for the different parameters that characterize the cerebrospinal fluid (CSF) flow dynamics in the aqueduct of Sylvius (velocity, flow, volume per cycle, and CSF production) obtained from phase-contrast MR images using a reliable and reproducible post-processing method. The optimized semiautomatic method eliminates interobserver variability and corrects errors due to low amplitude movements, aliasing, and the partial volume effect.

We studied 42 healthy subjects without neurological or cerebrovascular disease or disturbances in CSF dynamics. Images were acquired on a 1.5 T MR scanner using a phase-contrast sequence. All images were acquired during the same time frame (14:00 to 18:00) to avoid circadian influences.

we obtained normal values for each of the parameters that characterize CSF dynamics in the aqueduct (maximum diastolic and systolic velocity, mean velocity, maximum diastolic and systolic flow, mean flow, production rate, and stroke volume). Although trends were noted, neither sex nor age (< 25, 26-50, >51 years old) had a statistically significant effect on any parameter (p> or =0.05).

Although measurements of CSF flow dynamics parameter are sensitive to various factors (temporal and spatial resolutions of the MR sequence, circadian rhythms, age, sex, and MR equipment manufacturer), an optimized post-processing method enables reliable and reproducible values and ranges for normal subjects to be established.