Depiction of vasculature in small hepatocellular carcinoma,and dysplastic nodules evaluated with carbon dioxide ultrasonography and angiography

Abstract

Purpose: To evaluate the vascularity in dysplastic nodules and well-differentiated and moderately to poorly differentiated hepatocellular carcinomas (HCCs) less than 2 cm using carbon-dioxide (CO₂) US and angiography.

Material and Methods: A total of 115 pathologically proven small liver tumors (0.7∼2.0 cm) were included in the study. There were 31 dysplastic nodules, 49 well-differentiated HCCs and 35 moderately to poorly differentiated HCCs. A comparative study of angiography and CO₂ US was carried out.

Results: Of the dysplastic nodules, 28 out of 31 tumors were hypo- or isovascular at CO₂ US. Twenty-seven out of 31 tumors were hypovascular at angiography. Of the well-differentiated HCCs, 38/49 showed hypervascularity at CO₂ US while 24/49 tumors were hypervascular at angiography. All moderately to poorly differentiated HCCs showed hypervascularity at CO₂ US, compared to 30/35 tumors at angiography.

Conclusion: Most of the dysplastic nodules were hypovascular and most of the moderately to poorly differentiated HCCs were hypervascular. The vascularity of well-differentiated HCCs was in between the above tumors. Both CO₂ US and angiography were equally effective in demonstrating the vascularities in dysplastic nodules and moderately to poorly differentiated HCCs. CO₂ US was significantly superior to angiography when identifying the vascularity in well-differentiated HCCs.