Aim: To look for the clinical implications of increased cortical fractional anisotropy (FA) in meningitis patients associated with brain abscess.
Material and Methods: Diffusion tensor imaging was performed in 10 patients of meningitis associated with brain abscess and 10 controls. The region of interest analysis was performed to calculate FA and mean diffusivity values from the abscess cavity and cortical regions of patients (enhancing and nonenhancing meninges on postcontrast T1-weighted images) and controls.
Results: Significantly increased FA values with no change in mean diffusivity values were found in enhancing (FA = 0.113 ± 0.023, P = 0.000) as well as nonenhancing (FA = 0.085 ± 0.009, P = 0.000) cortical region of patients compared with controls (FA = 0.067 ± 0.010).
Conclusions: Increased FA values in the enhancing as well as nonenhancing cortical regions suggest diffuse inflammatory activity in the pia-arachnoid in meningitis patients. It also suggests that FA may be a better indicator of active and diffuse meningeal inflammation than postcontrast T1-weighted images.