Table 2 The list of nodular signs in the relevant literature

Nodule size or lesion diameter

[6,7,8,9,10, 12,13,14,15,16,17,18, 21, 22]

Lobulation and spiculation

[9,10,11, 13,14,15,16,17,18,19, 21, 22]

Smoking history

[7, 12,13,14,15, 17, 21]

Pleural indentation

[10, 13, 17,18,19,20]

Lung cancer history

[12, 14,15,16,17]

The proportion of solid components within the lesion

[9, 15, 18, 19]

Air bronchogram

[18, 21, 22]

Vascular convergence sign

[9, 14, 19]