Measurement of the corpus callosum using magnetic resonance imaging: Analyses of methods and techniques

Since the first postmortem report of sex-related differences in the size of the human corpus callosum, a number of studies on sex differences have bee n published, but results conflicted. The aim of this review was not to asse ss the possible existence and magnitude of sex variations in the size of th e corpus callosum but to analyze methodological differences in several stud ies using Magnetic Resonance Imaging to investigate the sexual dimorphism i n the size of the corpus callosum. Methodological problems arise at several steps of the method: sampling, imagery techniques, and measurements. Moreo ver, the means of callosal areas obtained by the nine reported studies are significantly different. The hypothesis that methodological differences cou ld explain these differences is supported by statistical results. A common method for investigating sex-related differences in callosal morphology app ears necessary to resolve the question of a real sexual dimorphism of the c orpus callosum and its subregions.