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

Table 4 Prospective study of pattern combination-based classification of contrast-enhanced harmonic gray-scale sonography images for differentiating hepatic tumors

Enhancement pattern			No. of lesions			Diagnosis1
Patterncombi- nation	Arterial phase	Portalphase	HCC(n = 205)	Metastasis(n = 33)	Hemangioma(n = 45)2
1	A1	P1	183	3	0	HCC
2	A1	P2	0	0	0	HCC
3	A1	P3	0	5	0	Metastasis
4	A1	P4	0	0	0	HCC
5	A3	P1	0	1	1	Metastasis
6	A3	P2	0	1	0	Metastasis
7	A3	P3	0	14	0	Metastasis
8	A4	P1	0	0	16	Hemangioma
9	A4	P3	0	0	0	HCC
10	A4	P4	0	0	7	Hemangioma
11	Others3	P1	14	1	2	Hemangioma
12	Others3	P2	8	0	0	HCC
13	Others3	P3	0	8	0	Metastasis
14	Others3	P4	0	0	18	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 in the retrospective study.

²One case of hemangioma was not diagnosed because the pattern combination did not exist in Table 3.

³Others mean A2 or A5 as shown in Table 1.