Prospective study of differential diagnosis of hepatic tumors by pattern-based classification of contrast-enhanced sonography

Table 3 Enhancement pattern-based classification of contrast-enhanced harmonic gray-scale sonography images and positive predictive value for differentiating hepatic tumors

Enhancement pattern			Positive predictive value (No. of lesions)			Diagnosis1
Pattern combi- nation	Arterialphase	Portalphase	HCC(n = 178)	Metastasis(n = 56)	Hemangioma(n = 69)
1	A1	P1	0.996 (165)	0.004 (2)	0 (0)	HCC
2	A1	P2	1 (2)	0 (0)	0 (0)	HCC
3	A1	P3	0 (0)	1 (3)	0 (0)	Metastasis
4	A1	P4	1 (2)	0 (0)	0 (0)	HCC
5	A3	P1	0 (0)	1 (4)	0 (0)	Metastasis
6	A3	P2	0 (0)	1 (3)	0 (0)	Metastasis
7	A3	P3	0 (0)	1 (24)	0 (0)	Metastasis
8	A4	P1	0 (0)	0 (0)	1 (25)	Hemangioma
9	A4	P3	0.84 (2)	0 (0)	0.16 (1)	HCC
10	A4	P4	0 (0)	0 (0)	1 (16)	Hemangioma
11	others2	P1	0.20 (1)	0.19 (3)	0.61(8)	Hemangioma
12	others2	P2	0.79 (6)	0.21 (5)	0 (0)	HCC
13	others2	P3	0 (0)	1 (11)	0 (0)	Metastasis
14	others2	P4	0 (0)	0.04 (1)	0.96 (19)	Hemangioma

A1: Intratumoral vessels with homogeneous or heterogeneous enhancement; A3: Peritumoral vessels; A4: Peripheral nodular enhancement without tumor vessels; P1: homogeneous or heterogeneous enhancement; P2: Perfusion defect; P3: Ring enhancement; P4: Peripheral nodular enhancement.

¹Diagnosis was made on the basis of the largest positive predictive value for each of the three kinds of tumors in each combination of enhancement patterns.

²Others mean A2 or A5 as shown in Table 1.