Contrast-enhanced ultrasound of hepatocellular carcinoma: Correlation of washout time and angiogenesis.

Background: The use of the pure blood pool ultrasound contrast agent SonoVue (Bracco, Italy) with specific ultrasound imaging software has enabled the dynamic visualization of tumor microcirculation.

Aim: The present study was designed to investigate the washout time of hepatocellular carcinoma (HCC) and correlate it with angiogenesis parameters.

Methods: Thirty-one surgically confirmed HCC cases were prospectively evaluated with contrast-enhanced ultrasound (CEUS), and parameters such as wash-in time, peak enhancement time and washout time were determined offline. We also calculated microvessel density and the percentage of microvessel area (MVA) and compared CEUS parameters between a well differentiated group and a poorly to moderately differentiated group. The Spearman rank order correlation method was used to analyze the relationship between washout time and angiogenesis parameters.

Results: The washout time was longer in well differentiated HCC patients compared to those with poorly to moderately differentiated HCC (p < 0.05). In addition, the washout time of HCC was positively correlated with the percentage of MVA (r = 0.510).

Conclusions: Given that the percentage of MVA was positively correlated with tumor blood volume, washout time may be associated with HCC blood volume.