Fig. 4

Comparison of bAHD and Dice values for two examples of manually created errors. a A severe omission of small vessels is shown in the subpanel a. This error received a Dice score of 0.960 and a bAHD score of 0.65. b In subpanel b, a subtle boundary error of the internal carotid artery is shown. This error received a similar Dice value of 0.963, however, it received a lower bAHD value of 0.039. Please note that distance based measures assign lower values to better segmentations. bAHD is sensitive to the error in subpanel a and penalises the omission of small vessels because it considers voxel localisation. In contrast, Dice, which measures only the overlap, cannot distinguish between the two errors. Red: True positive voxels, Green: False-positive voxels, Blue: False-negative voxels