Sex differences of human corpus callosum revealed by polar coordinate system: magnetic resonance imaging study

Evaluation of morphological and size changes related to various pathological conditions of the corpus callosum (CC) requires the data about sex dimorphism of the CC. The purpose of our study is to define potential morphological sex differences of the CC by the use of polar coordinate system as a system of measurements.

After division of the CC into three equal segments by the use of polar coordinate system, we investigated the length of the hemisphere (A-A'), the CC size as its midsagittal section area (CCA), the size of its segments (C1, C2, C3), thickness of the thinnest part of the CC (TCC) and the angular coordinate (a angle) of dorsal point of the TCC in a sample of 30 human brains magnetic resonance images (15 males and 15 females, age 20-50 years).

We found significantly larger CCA, C3 segment and the TCC in males. Statistically significant correlation in both, males and females, was found between parameters of the CCA and of all of its segments (C1, C2, C3), the C1 and C2, the C2 and C3 segments, as well as like as between the C2 and TCC. Sex differences were also in findings of significant correlation between the C1 and C3 segments, between CCA and TCC, and of significant negative correlation between the a angle and A-A' only in females.

We concluded that the use of polar coordinate system appropriately reflects the anatomical and encephalometric characteristics of human CC.