Usefulness of the post-vascular phase of contrast-enhanced ultrasonography with sonazoid in the evaluation of gross types of hepatocellular carcinoma.

Objective: The purpose of this study was to assess the usefulness of post-vascular phase (PVP) images of contrast-enhanced ultrasonography (CE-US) in the evaluation of the gross types of hepatocellular carcinoma (HCC) that is closely related to the malignant potential of the tumor.

Methods: A total of 29 patients with 40 HCCs of <5 cm in diameter, who underwent hepatic resection, were enrolled. The gross type of the tumor was evaluated using real-time scanning during the PVP of CE-US with Sonazoid prior to surgery. The tumors were classified into three types based on the macroscopic classification of the Liver Cancer Study Group of Japan: single nodular (SN) type, single nodular with extranodular growth (SNEG) type, and confluent multinodular (CMN) type. The ability of CE-US to correctly depict the gross type of HCC was evaluated.

Results: 26 tumors were macroscopically diagnosed as the SN type, 11 tumors as the SNEG type, and 3 tumors as the CMN type. The sensitivity, specificity and accuracy of CE-US were 96, 80 and 90%, respectively.

Conclusion: The PVP image of CE-US with Sonazoid is a useful tool in the evaluation of the gross type of HCC and is considered essential in deciding treatment strategy.