Statistical Shape Analysis of the Corpus Callosum in Subtypes of Autism

Brain imaging studies of the corpus callosum (CC) in autism have yielded inconsistent results. In this paper, we explore the three-dimensional profile of CC abnormalities in autism. The CC is segmented from mid-sagittal MRI and four adjacent slices on both sides, using our newly developed semiautomatic method. A subsequent contour stitching is performed to create the 3D surface of the CC, and the point correspondence problem can be simplified by our segmentation scheme. After alignment, differences from each surface to a template are computed to create a signed distance map of each subject. The group difference in the distance map is analyzed using two sample t-test, which results in a significance map. The statistical results reveal significant difference between patients and controls in the body of the CC.