Analysis of the parameters derived from the diffusion tensor in autistic and language-impaired patients in magnetic resonance imaging

The diffusion tensor images generate a set of measurements that probe the structure of the white matter pathways in the brain. On the other hand, it is possible to analyze a whole set of images of a group of patients in a statistical study called connectometry, which uses permutation and boos trapping tests to correlate qualitative or quantitative variables with the parameters derived from the diffusion tensor. In connectometry, the images obtained through the spin density function, responsible for generating the signal and with a dependence on the coordinates of the stereotaxic reference frame in the patient, are mapped to a common space that is constructed by means of an atlas of weighted images in T1 of a patients group. The mathematical transformation used is known as diffeomorphism and its usefulness is to guarantee that the mapping function has an inverse and is differentiable, in order to have the equivalent image in the atlas coordinates. In this work, the diagnosis of patients as an ordinal qualitative variable of a group of 41 right-handed patients, 5 women and 36 men, where 19 belong to the group of healthy patients from control, 17 are patients diagnosed with language problems and 5 were diagnosed with Autism Spectrum Disorder. Due to the very different size between the study groups, the permutation test, as it is computationally robust, is adequate and minimizes the error that could be generated by this characteristic. The parameters used in this work correspond to Fractional Anisotropy, Average Diffusivity, Axial Diffusivity and Radial Diffusivity. In the results, significant correlations in the cerebellar tracts and the corpus callosum were observed in patients with language problems, which coincides with the literature, where models have been proposed in which the cerebellum is involved in more complex functions such as the language, contrary to what is classically considered, as a regulator of movements. (Author)