Cerebrospinal Fluid Flow Analysis in Tuberculous Meningitis Using Phase Contrast Technique on 3 Tesla MRI: A New Paradigm and Our Initial Experience.

Background: Phase-contrast magnetic resonance imaging (PC-MRI) has been used for studying cerebrospinal fluid (CSF) dynamics in various CSF related disorders at aqueduct of Sylvius. Objective: To analyze the CSF flow dynamics qualitatively and quantitatively using PC-MRI across the aqueduct of Sylvius in diagnosed patients of tuberculous meningitis. Methods: Thirty patients, clinically diagnosed with tuberculous meningitis and mean age of 24 years (range: 12-60 years) were taken up to study the changes in CSF flow dynamics using PC-MRI with retrospective cardiac gating. Thirty age and sex matched healthy volunteers were also included for comparison and reference values. Flow quantification was done by through-plane scans acquired in the axial plane perpendicular to the aqueduct. For qualitative examination, in-plane phase contrast scans were acquired in the mid-sagittal plane. Encoding velocity was kept in craniocaudal direction. Calculated parameters were peak velocity (cm/s), average velocity (cm/s), average flow (mL/s), net forward volume (mL), and stroke volume (µL). Results: Qualitatively, loss of normal sinusoidal waveform of CSF flow was noted in two cases of hydrocephalus with exaggerated flows. Quantitatively, CSF flow parameters showed marked numerical difference in tuberculous meningitis patients with hydrocephalus on comparison with healthy volunteers and with cases without hydrocephalus. Conclusion: PC-MRI is a sensitive technique to analyze altered CSF flow dynamics in tuberculous meningitis patients. This is a useful adjunct in imaging these patients to extract both the qualitative and quantitative information about CSF flow for comprehensive evaluation.