Differential features of cortical folds

Analysis of functional images of the brain increasingly relies on individual anatomy of subjects. The aim is the construction of accurate anatomy-indexed functional mappings which would be of crucial importance for neurosurgical planning. The major difficulty relies in the important inter-subject structural variability of the cortical anatomy. In this paper, we assume that a large part of this variability can be overcome if more elementary and stable units than sulci and gyri are chosen to analyse cortex anatomy. Hence, we try to highlight such features using differential geometry. A method extracting cortical fold crest lines is described first. Then a morphological decomposition of sulci along crest lines is proposed. Finally, the relevance of this approach is demonstrated by a segmentation of central sulcus into two stable parts for ten subjects.