Morphometric evaluation of the human corpus callosum using magnetic resonance imaging: Sex difference and relationship to age and intracranial size

Introduction: The objective of this study was to determine the normal values of corpus callosum (CC) subregions in healthy adult individuals in our population using magnetic resonance imaging (MRI) and to reveal gender differences during normal aging. Material and Methods: We performed the measurements of certain CC dimensions in 104 (44 males and 60 females) individuals. MRI imaging device was used for the measurements. The subregions of CC were measured with the midsagittal images. After the measurements of CC and its sections' (rostrum [R], genus [G], anterior body, posterior body, isthmus [I], and splenium [S]), length (L), width (W), and area (A) were carried out, the intracranial volume (ICV) and intracranial area (ICA) values were calculated. The Student's t-test and Pearson correlation test were used for statistical analysis. Results: Morphometric data of length, width, area, ICV, and ICA were collected. No significant difference was identified in CC morphometry by age among the patients (P > 0.05). Indicating longer diameters in males, the differences between the genders were significant (P < 0.05). Moreover, the mean of R-L, G-A, and G-W measurements was found significant between the age groups (P < 0.001). Conclusion: Sexual dimorphism in the CC is not a simple artifact of sex differences in brain size and may reflect differences in connectivity necessitated by differences in brain sizes.