Cerebrospinal fluid flow measured by phase-contrast cine MR.

PURPOSE This prospective study was designed to establish the temporal and quantitative relationship between blood flow and cerebrospinal fluid (CSF) flow using a phase-contrast cine MR pulse sequence.

METHODS A cine phase-contrast MR pulse sequence using peripheral gating was used to measure CSF flow direction and velocity. Data were acquired continuously and interpolated into 16 images throughout the cardiac cycle.

RESULTS The timing of systolic CSF flow in the cervical subarachnoid space (SAS) correlated very closely to the brain arteriovenous blood flow difference during the cardiac cycle. This arteriovenous difference was a measure of brain expansion. Aqueduct CSF flow during the cardiac cycle differed from SAS flow in that systolic flow was delayed in comparison with systolic cervical SAS flow. The normal aqueductal oscillatory flow volume was 1.7 +/- .4 mL/min or 0.03 +/- 0.01 mL per cardiac cycle. This represented 14.5% +/- 3.1% of the total CSF flow and tissue displacement through the incisura which was 14.5 +/- 2.2 mL/min or 0.22 +/- 0.03 mL per cycle. CSF oscillatory flow volume in the cervical SAS was 39.0 +/- 4.0 mL/min or 0.65 +/- 0.08 mL per cycle.

CONCLUSION CSF flow can be measured. Results in healthy subjects show relatively low oscillatory flow through the aqueduct which is slightly out of phase (delayed) compared with SAS CSF flow.