Quantitative analysis of glioma cell invasion by diffusion tensor imaging.

We aimed to quantitatively analyze the invasion of glioma cells by diffusion tensor imaging (DTI). Twenty patients with glioma, who required surgical decompression, were included in this study. Peritumoral edematous regional tissues were harvested for tumor cell counting and cell density analysis to establish standards for degrees of tumor infiltration. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of water molecules in brain in five regions of interest (ROI) were measured by DTI: (i) the glioma region; (ii) peritumoral edematous tissue; (iii) surrounding edematous tissue; (iv) white matter; and (v) contralateral white matter. The correlation between FA and ADC values from different ROI, and degree of tumor infiltration was analysed. FA values tended to increase from the glioma region outwards, and the maximum amplification appeared between peritumoral edematous and surrounding edematous regions. FA values from peritumoral edematous regions were negatively correlated with the degree of glioma infiltration. ADC values increased significantly in the peritumoral edematous region, but changes in other regions were variable. FA values from peritumoral edematous regions should be used as an evaluation index for the invasion of glioma cells.