Table 2. Features of nodules in different calcification groups.

Features	Non-calcification group* (n=177)	Micro-calcification group* (n=159)	Macro-calcification group * (n=181)	P value @
No. of males/females	34/143	39/120	38/143	0.488
Age #	49.8 ± 13.6 [18-80]	52.5 ± 13.3 [23-82]	52.4 ± 12.0 [23-78]	0.134
No. of nodules	177	159	181	<0.001
No. of benign nodules	140 (79.1)	94 (59.1)	112 (61.9)
No. of malignant nodules	37 (20.9)	65 (40.9)	69 (38.1)
Size (mm) #	20.3 ± 10.9 [10.0-62.6]	19.6 ± 8.7 [10.0-59.7]	20.3 ± 8.0 [12.3-53.3]	0.748
Conventional SE score				0.041
No. of score 1	1 (0.6)	0 (0)	0 (0)
No. of score 2	41 (23.2)	31 (19.4)	40 (22.1)
No. of score 3	93 (52.5)	64 (40.3)	73 (40.3)
No. of score 4	35 (19.7)	48 (30.2)	54 (29.8)
No. of score 5	7 (4.0)	16 (10.1)	14 (7.7)
ARFI SE grade				0.012
No. of grade 1	1 (0.6)	1 (0.6)	0 ()
No. of grade 2	41 (23.2)	21 (13.2)	34 (18.0)
No. of grade 3	89 (50.3)	63 (39.6)	83 (45.9)
No. of grade 4	34 (19.2)	41 (25.8)	41 (22.7)
No. of grade 5	10 (5.6)	30 (18.9)	22 (12.2)
No. of grade 6	2 (1.1)	3 (1.9)	1 (0.6)
Maximum SWS of nodule # (m/s)	3.31 ± 2.01 [0.56-8.40]	4.64 ± 2.64 [0.70-8.40]	4.79 ± 2.67 [0.54-8.40]	< 0.001
Mean SWS of nodule # (m/s)	2.60 ± 1.49 [0.43-8.21]	3.27 ± 1.85 [0.85-8.01]	3.68 ± 2.26 [0.41-8.32]	< 0.001
Maximum SWS of surrounding tissue # (m/s)	2.55 ± 0.78 [0.91-5.88]	2.60 ± 0.69 [1.26-7.88]	2.65 ± 0.91 [0.82-7.64]	0.466
Mean SWS of surrounding tissue # (m/s)	2.21 ± 0.72 [0.80-5.88]	2.37 ± 0.78 [1.10-6.24]	2.27 ± 0.80 [0.42-6.35]	0.142

^*Numbers in parentheses are percentages.

^#Data are means ± standard deviations. Ranges are in brackets.

^@P values of nonparametric variables were determined by Chi-square test, and P values of continuous variables by one way analysis of variation.

Abbreviation: SE, strain elastography; ARFI, acoustic radiation force impulse; SWS, shear-wave speed.