Table 2.

The list of nodular signs in the relevant literature

Nodular signs	Literature
Nodule size or lesion diameter	[6–10, 12–18, 21, 22]
Lobulation and spiculation	[9–11, 13–19, 21, 22]
Smoking history	[7, 12–15, 17, 21]
Pleural indentation	[10, 13, 17–20]
Lung cancer history	[12, 14–17]
The proportion of solid components within the lesion	[9, 15, 18, 19]
Air bronchogram	[18, 21, 22]
Vascular convergence sign	[9, 14, 19]