The influence of handedness and gender on the microstructure of the human corpus callosum: a diffusion-tensor magnetic resonance imaging study.

The aim of the present study was to examine whether handedness and gender are associated with microstructural differences in human corpus callosum (CC). For this purpose, diffusion-tensor magnetic resonance imaging (DTI) was performed on 34 right- and 33 left-handed subjects of both sexes. Four quantitative variables (Mean Diffusion, Relative Anisotropy, parallel and orthogonal diffusion) were computed within the CC. A significantly increased anisotropy was found in left- as compared to right-handed subjects, and in men as compared to women. Additionally, both overall and orthogonal diffusion were significantly lower in left- than in right-handed subjects. Possible interpretations of these findings are discussed. The novel DTI technique promises to further advance current understanding of morphological structure in the living brain.