CEREBROSPINAL-FLUID FLOW WAVE-FORMS - EFFECT OF ALTERED CRANIAL VENOUS OUTFLOW - A PHASE-CONTRAST MR FLOW IMAGING STUDY

Our purpose was to assess the effect of alterations in the cranial ven ous outflow on cerebrospinal fluid (CSF) flow waveforms using phase-co ntrast MRI. Thirteen healthy subjects were assessed for CSF flow and c erebral vascular flow at the C2-3 level, both before and after jugular venous compression (JVC). The flow waveforms were assessed both as an aggregate, and after dividing subjects in two groups based on percent jugular venous flow (PJVF) i. e. jugular outflow expressed as percent of cerebral arterial inflow Group 1:7 subjects with PJVF more than an d including median (predominantly jugular outflow); Group 2:6 subjects with PJVF less than median (predominantly extra-jugular outflow). CSF waveforms: JVC produced rounding of contours and flattening of dicrot ic waves, with the effect being greater in group 1 than group 2, In gr oup 1, systolic upslopes of the waveforms increased. No significant ag gregate amplitude changes were noted; amplidutes increased in group 1 (P = 0.001), and decreased in group 2 (P = 0.03). Temporal interval to the maximum CSF systolic flow significantly increased in group 1. Vas cular flow: Arterial flow significantly decreased in group 1. Jugular flow significantly decreased in both groups. The results suggest that CSF flow waveforms are sensitive to alterations in the cranial venous outflow. Changes in group 1 are most likely because of an elevation in intracranial pressure. Analysis of CSF flow waveforms appears a promi sing noninvasive tool for assessment of cranial compartment.