Sexual dimorphism in the human corpus callosum? A comparison of methodologies

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

“…However, in division of the CC in 4 unequal subareas using same line, third one was called isthmus [15]. Only the female isthmus was the exception, being not different in size, while in all cases using 3 different methods mentioned above differences between the CC subareas were significant [6]. The CC subdivisions, including isthmus are arbitrary, while any partitioning method should be based on an anatomical rationale.…”

“…Age range in our sample, without old subjects, excluded possibility of significant age effect [12], where most of the older women had a slender and almost symmetrical CC [10], with the tendency of the splenium to expand with age [8]. The genu-splenial line, which we used as polar axis, represents the middle position between two extremes (intercommissural and Chamberalin's lines) of three orientation systems and in fact may prove to contain the fewest number of confounding variables [6].…”

“…For discussion and overview of conflicting results, as well as for exhaustive reviews of errors and numerous causes of potential false conclusions see several papers [1,3,10,12,18,28]. In short, there are three main areas of important methodological problems: 1) sampling and subject material, 2) measurement procedure, and 3) appropriateness of using absolute or relative values [6].…”

“…In the studies of the CC size and morphology, including measurements of midsagittal surface area, were used: straight-line method (genu-splenial line, intercommissural line and Chamberalin's line) [6], curved-line method, bent line method (centre of gravity, medium line from the rostrum to splenium) [4], and radial gravity method [3]. These methods included different subdivisions of the CC, like subdivision in 7 subareas using the length of the CC [28] or the intercommissural line [26], division in 4 unequal subareas using intercommissural line [15], and the indexes, like slenderness index [4] or callosal ratio [26].…”

Automated Segmentation of the Corpus Callosum Midsagittal Surface Area

“…Similar studies were proposed by several different authors using MR manual segmentation or other dissection techniques [6,7,8,9,10,11,12,13,14]. Automatic segmentation of other specific brain regions, such as the hippocampus, may play an important role on Alzheimer´s disease, even when symptoms are still subtle [4].…”