Magnetic Resonance Imaging Cerebrospinal Fluid Hydrodynamics in Patients with Meningitis

The objective of the study was to evaluate the cerebrospinal fluid (CSF) flow alterations in meningitis using phase-contrast magnetic resonance imaging (PCMRI).

Fifty patients with clinically confirmed or strongly suspected infectious meningitis and 20 controls were evaluated with MRI. Quantitative CSF analysis was performed at the level of cerebral aqueduct using cardiac-gated PCMRI. Velocity encoding (Venc) was kept at 20 cm/s. Patients were subdivided into Group I (patients with hydrocephalus [n = 21]) and Group II (patients without hydrocephalus [n = 29]).

The mean peak velocity and stroke volume in controls were 2.49 ± 0.86 cm/s and 13.23 ± 6.84 µl and in patients were 2.85 ± 2.90 cm/s and 16.30 ± 20.02 µl, respectively. A wide variation of flow parameters was noted in meningitis irrespective of the degree of ventricular dilatation. A significant difference in peak velocity and stroke volume was noted in Group II as compared to controls. Viral meningitis showed milder alteration of CSF flow dynamics as compared to bacterial and tuberculous etiologies. At a cutoff value of 3.57 cm/s in peak CSF velocity, the specificity was 100% and sensitivity was 22.7% to differentiate between viral and non-viral meningitis.

Alteration of CSF flow dynamics on PCMRI can improve segregation of patients into viral and non- viral etiologies, especially in those in whom contrast is contraindicated or not recommended. This may aid in institution of appropriate clinical treatment.