Arterial Hyperenhancement: Intense contrast enhancement of a lesion during the arterial phase; combined with late-phase washout, it is diagnostic of HCC in cirrhotic livers.
Arterial hyperenhancement is the pattern of rapid, intense enhancement of a lesion during the arterial phase of contrast-enhanced ultrasound (CEUS), CT, or MRI, reflecting neovascularity. In the liver, arterial hyperenhancement followed by portal or late phase washout is the hallmark of hepatocellular carcinoma (HCC) and is sufficient for diagnosis without biopsy in cirrhotic patients ≥1 cm per LI-RADS and EASL guidelines.