Contrast‐enhanced ultrasound features of hepatocellular carcinoma in dogs.

Background: This study aimed to describe the contrast‐enhanced ultrasound (CEUS) features of canine hepatocellular carcinoma (HCC) in relation to cellular differentiation and lesion size. Methods: Sixty dogs with a cytological diagnosis of HCC and that underwent a CEUS examination were retrospectively selected. The wash‐in and wash‐out patterns of contrast enhancement, along with the time to wash‐in and the time to wash‐out, of each lesion were recorded. A dimensional cut‐off value of 3 cm was adopted for classification. Results: Cellular differentiation had a significant influence on both wash‐in (chi‐squared=16.99; P<0.001) and wash‐out (chi‐squared=10.9; P=0.004) patterns of contrast enhancement. Lesion size had a lower, but still significant, influence on both wash‐in (chi‐squared=12.7; P=0.005) and wash‐out (chi‐squared=7.42; P=0.024) patterns. A homogeneous hyperenhancement in the arterial phase followed by homogeneous wash‐out were suggestive of a well‐differentiated HCC. The cellular differentiation of lesions with inhomogeneous hyperenhancement or hypoenhancement/no enhancement as well as an inhomogeneous wash‐out or no wash‐out could not be inferred. Conclusions: No significant difference in the time to wash‐in and the time to wash‐out in relation to cellular differentiation or lesion size was evident. CEUS has the potential to improve efficiency in the diagnosis of HCCs in dogs. [ABSTRACT FROM AUTHOR]