Table 4.

Comparison of segmentation results of the proposed segmentation method with the segmentation method of Kubota et al., Kuhnigk et al., and Moltz et al. considering 891 nodules of LIDC-IDRI data set. For metrics PF, Accuracy, Overlap, Sensitivity, Specificity, SR the maximum and for metrics MD, HD, MHD, SA the minimum values are emphasized with italics.

Comparative analysis		Kuhnigk et al.		Moltz et al.		Kubota et al.		Proposed method
Nodule	Metric	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Solid/	MD	3.65	2.55	3.04	1.83	4.56	3.60	2.85	1.84
part-solid	PF	0.48	0.27	0.58	0.17	0.50	0.23	0.62	0.14
	HD	4.93	4.50	4.49	4.02	8.98	7.00	5.01	5.11
	MHD	2.90	4.30	1.62	2.53	3.05	3.37	1.46	2.41
	Accuracy	0.99	0.01	0.99	0.01	0.97	0.05	0.99	0.01
	Overlap	0.35	0.23	0.41	0.18	0.34	0.15	0.46	0.16
	Sensitivity	0.39	0.26	0.48	0.19	0.56	0.16	0.58	0.16
	Specificity	1.00	0.00	1.00	0.00	0.97	0.05	0.99	0.01
	SA	1.02	0.33	0.94	0.23	1.01	0.23	0.88	0.20
	SR	0.47	0.28	0.55	0.21	0.48	0.23	0.61	0.18
Non-solid	MD	6.36	2.49	6.19	2.50	6.81	0.39	3.24	1.89
	PF	0.05	0.14	0.07	0.17	0.36	0.23	0.56	0.15
	HD	9.05	4.22	8.15	3.17	13.38	6.44	4.93	3.35
	MHD	8.28	4.05	7.49	4.2	5.45	3.88	1.78	2.96
	Accuracy	0.98	0.00	0.98	0.02	0.94	0.06	0.98	0.02
	Overlap	0.00	0.02	0.02	0.06	0.18	0.15	0.32	0.12
	Sensitivity	0.01	0.03	0.03	0.07	0.40	0.18	0.44	0.16
	Specificity	1.00	0.00	1.00	0.00	0.95	0.06	1.00	0.00
	SA	1.57	0.00	1.51	0.13	1.24	0.21	1.04	0.16
	SR	0.02	0.06	0.04	0.10	0.27	0.23	0.47	0.15

MD mean distance, PF Pratt function, HD Hausdorff distance, MHD modified Hausdorff distance, SA similarity angle, SM similarity measure