A novel framework for analyzing cortical folding patterns based on sulcal baselines and gyral crestlines

One of the most important morphometric features of cerebral cortex is its convex (gyri) and concave (sulci) folding pattern. Previous studies have shown that sulci and gyri have different anatomical and connectivity patterns. However, most cortical morphometric studies do not differentiate them and few studies have focused on the convolution folding pattern of gyri and sulci separately. In this paper, we developed a novel computational framework to study the morphometric patterns of gyral crestline and sulcal baseline in autism spectrum disorder (ASD). Specifically, the crestlines of eight major gyri and the baseline of two major sulci have been measured on each hemisphere. Our results showed dominantly decreased cortical thickness and increased curvature to the tangential direction of cortical sphere in the brain regions of ASD. Moreover, by using curvature along the lines as its shape feature vector, k-means clustering was performed to cluster the lines with similar shape patterns. Both ASD dominant clusters with more curved patterns and healthy control dominant clusters with less curved patterns were identified. These results coincide with the findings in brain developmental studies that thinner cortex will be more curved and our study may add new insights to the developing mechanism of the cause of ASD.