Table 2 Comparison of sonographic characteristics of non-diffuse PTL and PTC

(n = 100)

(n = 50)

Nodule size (mm, ‾x ± s)

31.86 ± 9.40

44.70 ± 15.50

t' = -5.384

 < 0.001

Echo texture

χ² = 0.000^*

1.000

 Homogeneous

1(1.0%)

0(0.0%)

 Heterogeneous

99(99.0%)

50(100%)

Echogenicity

χ² =57.429

 < 0.001^a

 Markedly hypoechoic

2 (2.0%)

27 (54.0%)

 Hypoechoic

93 (93.0%)

23 (46.0%)

 Equal or high echo

5 (5.0%)

0 (0.0%)

Internal linear echogenic strands

χ² = 45.054

 < 0.001

 Yes

34(34.0%)

46(92.0%)

 No

66(66.0%)

4(8.0%)

Anteroposterior-to-transverse ratio > 1

χ² = 0.917^*

0.338

 Yes

10 (10.0%)

2 (4.0%)

 No

90 (90.0%)

48 (96.0%)

Margin

χ² = 13.787

 < 0.001

 Regular

22(22.0%)

26(52.0%)

 Irregular

78(78.0%)

24(48.0%)

Posterior echo enhancement

χ² = 56.305

 < 0.001

 Yes

20(20.0%)

42(84.0%)

 No

80(80.0%)

8(16.0%)

Cystic change

χ² = 3.043^*

0.081

 Yes

12 (12.0%)

1 (2.0%)

 No

88 (88.0%)

49 (98.0%)

Calcification

χ² = 52.380

 < 0.001

 Mirco/coarse

78 (78.0%)

8 (16.0%)

 None

22 (22.0%)

42 (84.0%)

Vascularity

χ² = 4.500

0.034

 Absence/not rich vascularity

46 (46.0%)

14 (28.0%)

 Rich vascularity

54 (54.0%)

36 (72.0%)

Capsular invasion

χ² = 18.803

 < 0.001

 Yes

83(83.0%)

24(48.0%)

 No

17(17.0%)

26(52.0%)