In contrast-enhanced 1.5 harmonic imaging sonography, images are obtained in a band intermediate between the fundamental and the 2nd harmonic components. In the present study, we investigated the usefulness of 1.5 harmonic imaging sonography with the use of the contrast agent Levovist for the diagnosis of hepatocellular carcinoma (HCC), metastatic hepatic tumor, and hepatic hemangioma. The subjects in this study were 64 patients with 70 nodules of hepatic tumors (42 nodules in 36 cases of hepatocellular carcinoma, 20 nodules in 20 cases of metastatic hepatic tumor, and 8 nodules in 8 cases of hepatic hemangioma). Contrast enhancement of tumors acquired in the early, portal, and late phases with 1.5 harmonic imaging sonography were compared to classify the tumors. 1.5 harmonic imaging sonography of HCC showed contrast enhancement of 36 nodules (85.7%). Hypervascular enhancement in the early phase, which was maintained in the portal phase, changed to images with no contrast enhancement with partial persistence of contrast enhancement in the late phase. 1.5 harmonic imaging sonography of metastatic hepatic tumor showed hypervascular enhancement of the margin of 20 nodules (100%) in the early and portal phases, which changed to images with no contrast enhancement in the late phase. 1.5 harmonic imaging sonography of hepatic hemangiomas maintained hypervascular enhancement on the tumor margin of 5 nodules (62.5%) in the early and portal phases. When early phase 1.5 harmonic imaging sonography did not show hypervascular enhancement in 3 nodules (37.5%), and late-phase images confirmed that these 3 nodules were hypervascular enhancement on the tumor margin. 1.5 harmonic imaging sonography of hepatic tumors (hepatocellular carcinoma, metastatic hepatic tumor and hepatic hemangioma) provided characteristic findings of contrast enhancement in the early, portal, and late phases, and will contribute to differential diagnosis.

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