TABLE 1.

Description of semantic features

Characteristic	Definition	Scoring
Location
1. Lobe Location	Lobe location of the nodule	left lower lung (5), left upper lung (4), right lower lung (3), right top lung (2), right upper lung (1)
Size
2. Long-axis Diameter	Longest diameter of the nodule	NA
3. Short-axis Diameter	Longest perpendicular diameter of nodule in the same section	NA
Shape
4. Contour	Roundness of the nodule	1, round; 2, oval; 3, irregular
5. Lobulation	Wavy nodule’s surface	1, none; 2, yes
6. Concavity	Concave cut on nodule surface	1, none; 2, slight concavity; 3, deep concavity
Margin
7. Border Definition	Edge appearance of the nodule	1, well defined; 2, slight poorly; 3, poorly defined
8. Spiculation	Spike edge in the nodule	1, none; 2 yes
Attenuation
9. Texture	Solid, non-solid, part solid	1, non-solid; 2, part solid; 3, solid
External
10. Fissure Attachment	Nodule attaches to the fissure	0, no; 1, yes
11. Pleural Attachment	Nodules attaches to the pleura	0, no; 1, yes
12. Vascular Convergence	Convergence of vessels to nodule	0, no significant convergence; 1, significant
13. Pleural Retraction	Retraction of the pleura towards nodule	0, absence of pleural retraction; 1, present
14. Peripheral emphysema	Peripheral emphysema caused by nodule	1, absence of emphysema; 2, slight present; 3 severely present
15. Peripheral Fibrosis	Peripheral fibrosis caused by nodule	1, absence of fibrosis; 2, slight present; 3 severely present
16. Vessel Attachment	Nodule attachment to blood vessel	0, no; 1, yes
17. Cavitation	Cavity within nodule due to fibrosis	0, no; 1, yes
Associated Findings
18. Nodules in primary lobe	Any nodules suspected to be malignant	0, no; 1, yes
19. Nodules in non-tumor lobe	Any nodules suspected to be malignant	0, no; 1, yes
20. Lymphadenopathy	Lymph nodes with short- axis diameter greater than 1 cm	0, no; 1, yes