Correction of segmented lung boundary for inclusion of pleural nodules and pulmonary vessels in chest CT images.

We propose a new curvature-based method for correcting the segmented lung boundary. Our method consists of the following steps. First, the lungs are extracted from chest CT images by the automatic segmentation method. Second, the segmented lung contours are corrected by lung smoothing in each axial slice. Our scan line search provides an efficient contour tracing and curvature calculation. Finally, the smoothed lung contours are corrected by 3D VOI refinement. This increases the smoothness in the z-axis without distortion of the lung boundary. Experimental results show that our method effectively incorporates the pleural nodules and pulmonary vessels into the segmentation results.