Segmentation of rib bones from MR data using tracking approach and polynomial parametrization

Segmentation of rib bones from magnetic resonance (MR) data is a challenging task due to the very weak MR signal of the bone tissue. The locations of the rib bones are indicated by the lack of signal between the surrounding soft tissues. We have developed an automated rib segmentation method, which tracks the bones from a given initial point using a predefined rib cross-section template. The three-dimensional location of the rib midline is parametrized with second order polynomials. The correct rib midline is determined through numerical optimization of polynomial parameters by maximizing cross-correlation between the template and the MR data. The segmentation result is a three-dimensional binary segmentation of the ribs, which can be output also as a surface. Comparison between the method´s output and a manual segmentation shows that the method works adequately.