In vivo demonstration of neuroinflammatory molecule expression in brain abscess with diffusion tensor imaging.

BACKGROUND AND PURPOSE Neuroinflammatory molecules, including tumor necrosis factor-alpha, interleukin1-beta, lymphocyte function associated molecule-1, and intercellular cell adhesion molecule-1 contribute to the development of brain abscess. We hypothesized that the high fractional anisotropy (FA) in the brain abscess cavity reflects the upregulation of these neuroinflammatory molecules. MATERIALS AND METHODS Diffusion tensor imaging (DTI) was performed in 24 patients with brain abscess and Staphylococcus aureus-treated as well as nontreated Jurket cell lines (at 4 time points: 1, 24, 48, and 72 hours). Neuroinflammatory molecules were quantified from the brain abscess cavity aspirate of the patients as well as from the heat-killed S aureus-treated and nontreated cell lines and correlated with DTI measures. RESULTS The DTI-derived FA strongly correlated with the presence of neuroinflammatory molecules in the pus as well as in S aureus-treated cell lines; no such correlation was observed in nontreated cell lines. CONCLUSIONS These data indicate that neuroinflammatory molecules confer high diffusion anisotropy inside the brain abscess cavity. We propose that increased FA reflects upregulated inflammatory response in brain abscess.