Clinical value of contrast-enhanced ultrasound in early diagnosis of small hepatocellular carcinoma (≤ 2 cm)

Table 1 Baseline characteristics of patients grouped according to classification of their liver nodules

Category	Patients (n = 364)		P value
	HCC (n = 65)	Non-HCC (n = 299)
Age (yr), mean ± SD	49.86 ± 0.84	60.40 ± 1.72	< 0.001
Male, n (%)	45 (69.23)	218 (72.90)	NS
Family history of HCC, n (%)	8 (12.31)	11 (3.67)	NS
BMI (kg/m2), n (%)			NS
> 28	4 (6.15)	28 (9.36)
≤ 28	61 (93.85)	211 (90.94)
HBV, n (%)	65 (100)	219 (73.24)	< 0.01
HCV, n (%)	2 (3.08)	24 (8.03)	NS
Alcohol cirrhosis, n (%)	2 (3.08)	5 (1.67)	NS
Diabetes, n (%)	8 (12.3)	46 (15.38)	NS

HCC: Hepatocellular carcinoma; BMI: Body mass index; HBV: Hepatitis B virus; HCV: Hepatitis C virus; NS: No significant.

Table 2 Comparison of ultrasonographic characteristics between hepatocellular carcinoma and non-hepatocellular carcinoma nodules

Category	Nodules (n = 551)		P value
	HCC (n = 65)	Non-HCC (n = 486)
Ultrasonographic characteristics, n (%)			< 0.05
Hyperecho	13 (20)	175 (36.01)
Isoecho	5 (7.69)	12 (2.47)
Hypoecho	47 (72.31)	299 (61.52)
Nodule size (mm)	14.6 ± 0.48	12.2 ± 10.27	< 0.05
Location, n (%)			NS
Left liver	9 (13.85)	77 (15.84)
Right liver	56 (86.15)	409 (84.16)

HCC: Hepatocellular carcinoma; NS: No significant.

Table 3 Contrast-enhanced ultrasound findings in cirrhotic nodules, dysplastic nodules, and hepatocellular carcinoma

CEUS characteristic, n (%)	Nodules (n = 551)			P value
	CN (n = 467)	DN (n = 19)	HCC (n = 65)
Arterial phase				< 0.05
Hyperecho	0	1 (5.26)	56 (83.60)
Isoecho	438 (93.79)	8 (42.11)	9 (16.40)
Hypoecho	29 (6.21)	10 (52.63)	0
Portal phase				< 0.05
Hyperecho	0	0	0
Isoecho	464 (99.36)	17 (89.47)	50 (72.71)
Hypoecho	3 (0.64)	2 (10.53)	15 (27.29)
Delayed phase				< 0.05
Hyperecho	0	0	0
Isoecho	464 (99.36)	17 (89.47)	27 (41.54)
Hypoecho	3 (0.64)	2 (10.53)	38 (58.46)

CEUS: Contrast-enhanced ultrasound; CN: Cirrhotic nodule; DN: Dysplasia; HCC: Hepatocellular carcinoma.

Table 4 Contrast-enhanced ultrasound findings in small hepatocellular carcinoma of different sizes

Category	Nodule size		P value
	≤ 1 cm	1-2 cm
No.	13	52
Type of echo, n (%)			NS
Hyperecho	1 (7.69)	8 (15.38)
Isoecho	2 (15.38)	14 (26.92)
Hypoecho	10 (76.92)	30 (57.69)
Enhancement time (s), mean ± SD	15.12 ± 1.44	19.90 ± 0.61	< 0.05
Wash-out time (s), mean ± SD	115.20 ± 10.25	80.13 ± 13.18	NS
Arterial phase (0-30 s), n (%)	0	1 (1.92%)
Portal phase (31-120 s), n (%)	4 (30.77)	28 (53.85)
Delayed phase (121-360s), n (%)	1 (7.69)	4 (7.69)
> 360 s, n (%)	8 (61.54)	19 (36.54)
CEUS pattern, n (%)			< 0.05
Fast-in and fast-out	5 (38.46)	33 (63.46)
Fast-in and isochronous-out	8 (61.54)	19 (36.54)

CEUS: Contrast-enhanced ultrasound; NS: No significant.