ABSTRACT
Differential diagnosis of focal nodular hyperplasia and hepatocellular carcinoma is clinically important because, while both are hypervascular tumors, they have vastly different prognoses. Because the spoke-wheel appearance is the primary characteristic of focal nodular hyperplasia, we attempted to detect this pattern in nodules smaller than 3 cm in diameter with contrast-enhanced ultrasonography using a contrast agent (Levovist). Four patients were examined with contrast-enhanced US: two of the patients were examined with Coded Harmonic Angio; the other two patients were examined with contrast-enhanced color and power Doppler US without harmonic imaging. Although the hepatic arteriogram showed the spoke-wheel appearance in only one tumor (diameter, 3 cm), contrast-enhanced US clearly demonstrated this characteristic in all four tumors, including three tumors that were less than 2 cm in diameter. Because it is noninvasive and can be carried out in an outpatient clinic, contrast-enhanced US is extremely useful for diagnosing small focal noduler hyperplasia lesions at sites that can be observed with US.
