Semiquantitative characterization of hepatocellular carcinoma (HCC)--perfusion with contrast-enhanced ultrasound and perfusion analysis.

Background: At the moment, there is only poor specificity of HCC-detection in tumors smaller than 2 cm in a cirrhotic liver. Thus, efforts have to be made to optimize the distinction between regenerative nodules and HCC.

Aims: The aim of our study was to describe the particular perfusion pattern of hepatocellular carcinoma using a specific quantification software.

Methods: We evaluated 25 patients with proven hepatocellular carcinoma, who underwent dynamic contrast-enhanced ultrasound (CEUS) using a second generation contrast agent (SonoVue, Bracco, Germany). Retrospectively, we applied the quantification software Qontrast (Bracco, Milan, Italy) to obtain contrast-enhanced sonographic perfusion maps for each lesion.

Results: We found a close positive correlation of the perfusion parameters peak, time-to-peak and regional blood volume between the entire tumors, the center (center/total) and the periphery of the tumors (periphery/total), respectively. Moreover, we found significant higher peak values, a significant higher regional blood volume and a trend to lower time-to-peak in the center of the tumors compared to the tumor periphery.

Conclusion: These results suggest a better established vascular bed in the center of the tumors. This could be a sonographic marker of HCC in contrast to regenerative nodules.