A PROBABILISTIC RIBBON MODEL FOR SHAPE-ANALYSIS OF THE CEREBRAL SULCI- APPLICATION TO THE CENTRAL SULCUS

Purpose: An approach for quantifying the shapes of the cerebral sulci is presented, utilizing a probabilistic geometric model, and it is app lied to the central sulcus. Method: The geometric structure of the cen tral sulcus is determined from a set of outlines on cross-sectional im ages and is used by a procedure that automatically labels the major cr est lines, i.e., curves of locally maximal curvature, along the sulcus . An automated procedure then determines a parametric representation o f the central sulcus that is consistent across individuals, in that it assigns the same parametric coordinates to corresponding regions of t he sulcus. Results: The method is applied to the central sulci from 20 subjects. The use of this shape representation in cortical morphometr ic analysis applications is demonstrated, in particular in obtaining l ocal depth and curvature measurements of a sulcus as well as in determ ining average shapes and variability. Conclusion: With this method, we were able to build parametric representations of the sulcal ribbons b y preserving anatomical homologies.