Table 1.

Comparison of morphological features of lung metastasis (PM) and non- metastasis (NM) in the training and validation datasets.

	Training dataset			Validation dataset
Characteristics	NM	PM	p	NM	PM	p
Age	59.82 ± 10.530	58.17 ± 11.360	0.382	58.54 ± 12.188	56.06 ± 9.055	0.372
Gender			0.676			0.316
1	42 (57.5%)	34 (54.0%)		13 (46.4%)	19 (59.4%)
2	31 (42.5%)	29 (46.0%)		15 (53.6%)	13 (40.6%)
Lobe location			0.025*			0.507
1	12 (16.4%)	19 (30.2%)		7 (25.0%)	6 (18.8%)
2	12 (16.4%)	10 (15.9%)		4 (14.3%)	10 (31.3%)
3	23 (31.5%)	9 (14.3%)		8 (28.6%)	5 (15.6%)
4	12 (16.4%)	5 (7.9%)		1 (3.6%)	1 (3.1%)
5	14 (19.2%)	20 (31.7%)		8 (28.6%)	10 (31.3%)
Size category			<0.001*	0.00%	0.00%	0.095
1	56 (76.7%)	22 (34.9%)		20 (71.4%)	14 (43.8%)
2	10 (13.7%)	24 (38.1%)		4 (14.3%)	10 (31.3%)
3	7 (9.6%)	17 (27.0%)		4 (14.3%)	8 (25.0%)
Long-axis diameter	8.988 ± 3.493	12.662 ± 4.200	<0.001*	9.221 ± 4.422	11.819 ± 4.180	0.023*
Short-axis diameter	5.825 ± 2.144	9.611 ± 9.253	0.001*	5.682 ± 2.031	8.184 ± 3.071	<0.001*
Density			<0.001*			0.002*
1	12 (16.4%)	0 (0.0%)		6 (21.4%)	0 (0.0%)
2	15 (20.5%)	2 (3.2%)		6 (21.4%)	2 (6.3%)
3	46 (63.0%)	61 (96.8%)		16 (57.1%)	30 (93.8%)
Contour			0043*			0.011*
1	2 (2.7%)	10 (15.9%)		1 (3.6%)	1 (3.1%)
2	21 (28.8%)	20 (31.7%)		2 (7.1%)	8 (25.0%)
3	29 (39.7%)	19 (30.2%)		11 (39.3%)	19 (59.4%)
4	21 (28.8%)	14 (22.2%)		14 (50.0%)	4 (12.5%)
Border			<0.001*			<0.001*
1	28 (38.4%)	2 (3.2%)		13 (46.4%)	1 (3.1%)
2	24 (32.9%)	43 (68.3%)		10 (35.7%)	20 (62.5%)
3	21 (28.8%)	18 (28.6%)		5 (17.9%)	11 (34.4%)
Air bronchogram			0.032*			0.178
0	72 (98.6%)	57 (90.5%)		28 (100.0%)	30 (93.8%)
1	1 (1.4%)	6 (9.5%)		0 (0.0%)	2 (6.3%)
Lymphadenopathy			0.032*			0.369
0	72 (98.6%)	57 (90.5%)		27 (96.4%)	29 (90.6%)
1	1 (1.4%)	6 (9.5%)		1 (3.6%)	3 (9.4%)

Chi-square tests were used to compare the differences in categorical variables while a two-sample t-test was used to compare the differences in continuous variables.

NM, non-metastasis group; PM, lung metastasis group.

^*p < 0.05.