Finding 3D parametric representations of the deep cortical folds

Parametric representations of anatomical structures provide useful mathematical descriptions for many medical imaging applications, including morphological analysis of the brain. Here, the authors develop a methodology for obtaining a parametric representation of the deep cortical folds of the brain utilizing characteristics of the cortical shape. They first find a mathematical representation of the outer cortical surface using a deformable surface algorithm. Using the principal curvatures of the resulting surface, the authors then identify the edges on the sulci on it, and they initialize active contours along them. An external force field guides an active contour to the deep edge of a sulcus, along the medial surface of a cortical fold. A parametric description of a sulcal surface is obtained as the active contour traverses the sulcus, sweeping a surface resembling a convoluted ribbon embedded in 3D. Here, the authors present results using magnetic resonance images.