Table 2 CT characteristics of the benign and malignant nodules

Distribution

0.053

 Upper lobe

54 (42.2)

92 (53.5)

 Middle and lower lobes

74 (57.8)

80 (46.5)

Abutting the mediastinal pleura

10 (7.8)

43 (25.0)

 < 0.001

Size (mm)

14.55 ± 6.84

19.18 ± 6.07

 < 0.001

Shape (irregular)

8 (6.3)

9 (5.2)

0.706

Lobulation

23 (18.0)

128 (74.4)

 < 0.001

Spiculation

25 (19.5)

77 (44.8)

 < 0.001

Narrow basement

65 (50.8)

137 (79.7)

 < 0.001

Adjacent pleural change

0.229

 No

101 (78.9)

144 (83.7)

 Pleural thickening

27 (21.1)

28 (16.3)

R-thickening

1.31 ± 0.68

0.75 ± 0.27

 < 0.001*

Extrapleural fat thickening

14 (10.9)

24 (14.0)

0.437

Relationship between nodule and pleura

 < 0.001

 Type I

99 (77.3)

126 (73.3)

0.419

 Type II

12 (9.4)

24 (13.4)

0.145

 Type III

15 (11.7)

3 (1.7)

 < 0.001

 Type IV

2 (1.6)

20 (11.6)

0.001

Concomitant lesions in peripheral lung fields (yes)

51 (39.8)

43 (25.0)

0.006

Lymph node enlargement

0.002

 No

112 (87.5)

122 (70.9)

0.001

 Hilar or mediastinal lymph nodule enlargement

9 (7.0)

24 (14.0)

0.058

 Simultaneous hilar and mediastinal lymph nodule enlargement

7 (5.5)

26 (15.1)

0.008

Plain CT value (HU)

37.17 ± 30.0

33.06 ± 17.67

0.802

△CT value (HU)

45.85 ± 23.50

42.05 ± 19.17

0.463*