Detection of structural differences between the brains of schizophrenic patients and controls.

This paper investigates the validity of the null hypothesis: there are no structural differences between the brains of schizophrenic and normal control subjects that manifest themselves in MRI-T(2) data and distinguish the two populations in a statistically significant way. The data used refer to 21 schizophrenic patients and 19 normal controls, matched for age, sex and social background. The methodology used is based on three-dimensional texture analysis, which is used to quantify anisotropy in the data at scales of the order of a few millimetres. These data reject the null hypothesis. In addition, this article attempts to identify the regions of the brain that are responsible for the morphological characteristics that distinguish the two populations. For this purpose, it utilises a second texture analysis method that, in spite of being a global method, allows one to trace back to the data the origin of the features that most distinctly distinguish the two populations. This method indicates that the features that distinguish the two populations with P values smaller than 10(-6) are located in the most inferior part of the brain and in particular in the tissue that makes up the sulci. It is stressed that in order to preserve the integrity of the data for texture calculations, no registration of anatomical structures is performed, and the most inferior part of the brain is identified as referring to those slices of the scans that visually correspond to slices 1-12 of the Talairach and Tournoux brain atlas.