Perfluorobutane-enhanced ultrasonography with a Kupffer phase: improved diagnostic sensitivity for hepatocellular carcinoma.

• Applying Kupffer phase defect instead of late/mild washout and adjusting with grayscale findings can improve the diagnostic performance of perfluorobutane-enhanced US for HCC. • Adjustment with ill-defined margins without a hypoechoic halo for features unlikely to be HCC decreases false positives for HCC diagnosis using the perfluorobutane-enhanced US. • After adjustment with grayscale findings, the sensitivity and accuracy of the APHE and Kupffer criteria were higher than those of the LI-RADS criteria; specificity was 91.3% for both.