Figure 10e.

Potential failures of region-based segmentation methods. Six examples of potential failures of region-based segmentation methods show lung boundaries (red contours) and areas in which the algorithms fail (arrows). In particular, the structures that are excluded from lung segmentation are vascular structures (a, d), consolidations (b, c, f), and a pleural effusion (e). Compare with Figure 16, which shows optimal segmentation in similar cases with the use of the neighboring anatomy–guided segmentation method.