Active contours and surfaces with cubic splines for semiautomatic tracheal segmentation

Signs and symptoms of tracheal stenosis can create confusion about the etiology of the problem. While bronchoscopy is the diagnostic method of choice to evaluate the extension and localization of the lesion, the use of x-ray computed axial tomography (CAT) images has also been considered. Recent works on airway segmentation in CAT images propose the extensive use of automatic segmentation techniques based on 3-D region growing. This technique is computationally expensive and thus alternative analysis procedures are still under development. We present a segmentation method constructed over an active surface model based on cubic splines interpolation. The 3-D rendering of the upper-airway path segmented from neck and thorax CAT scans using the proposed method is validated in regard to its possible use as a diagnostic tool for the characterization of tracheal stenosis. The results presented relative to the performance of the model, both on synthetic and real CAT scan volumes, indicate that the proposed procedure improves over the reference active model methods.