Dependence of Shape-Based Descriptors and Mass Segmentation Areas on Initial Contour Placement Using the Chan-Vese Method on Digital Mammograms

Table 7

Mean values for the Jaccard similarity coefficient (JSC) and the Euclidean distances of the masses. The mean values and ranges of percentage differences in boundary moments (, , and ), percentage differences in shape convexity (%ΔSC), and percentage differences in shape rectangularity (%ΔSC) for the masses, labelled as groups with predefined margin characteristics and also a group with arbitrary margin characteristics, due to changes in the location of the initial level set contours evolved with the selective local or global segmentation model with tuneable parameter .

Margin characteristics	Obscured/ill-defined margins	Distinct/well-defined margins	Unlabelled margins
Average JSC	0.86 ± 0.09	0.91 ± 0.04	0.89 ± 0.07
Average DF	0.05 ± 0.04	0.04 ± 0.03	0.05 ± 0.04
Mean of	15.1%	11.1%	13.1%
Range of	0–74%	0–38%	0–74%
Mean of	15.4%	13.4%	14.4%
Range of	0–67.5%	0–44.2%	0–67.5%
Mean of	23.5%	15.1%	19.3%
Range of	0–52%	0–41.1%	0–52%
Mean of %ΔSC	10.2%	8.7%	9.5%
Range of %ΔSC	0–30%	0–25.1%	0–30%
Mean of %ΔSR	11.7%	9.2%	10.5%
Range of %ΔSR	0–30%	0–28%	0–30%