DIFFERENTIAL-DIAGNOSIS OF EARLY HOMOGENEOUSLY ENHANCING HEPATOCELLULAR-CARCINOMA AND HEMANGIOMA BY 2-PHASE CT

Purpose: Our goal was to differentiate between early homogeneously enh ancing hepatocellular carcinoma (HCC) and hemangioma by two-phase CT. Method: Two phase images of 51 HCCs and 28 hemangiomas showing homogen eous high attenuation in the first series (arterial dominant phase) we re reviewed. Enhancement patterns of the lesions in the second series (parenchymal phase) were classified as homogeneous high, peripheral hi gh, iso-, and low attenuation. The attenuation values of all and the e nhancement values of some (21 HCCs and 18 hemangiomas) in the first se ries were calculated. Results: Although low and peripheral high attenu ation patterns were seen during the second series only in HCCs (n = 35 ), which could be used to correctly diagnose HCC, other nonspecific pa tterns were demonstrated in both HCCs (n = 16) and hemangiomas (n = 28 ). The attenuation values of 49 of the 51 HCCs and 5 of the 28 hemangi omas were below 130 HU on the first series. The enhancement values of all 21 HCCs and 3 of 18 hemangiomas were below 70 HU. Combining the en hancement patterns with a borderline attenuation value of 130 HU or bo rderline enhancement value of 70 HU yielded overall accuracies of 94 a nd 92%, respectively. Conclusion: The combined criteria (enhancement p attern plus attenuation or enhancement value) were useful for differen tiating between early homogeneously enhancing HCCs and hemangiomas.