Dynamic contrast-enhanced power Doppler sonography improves the differential diagnosis of liver lesions

The aim of this paper was to investigate the diagnostic value of dynamic contrast-enhanced power Doppler sonography in the differential diagnosis of liver lesions. We prospectively examined 85 focal liver lesions in 71 patients by real-time gray-scale sonography, power Doppler sonography, and contrast-enhanced power Doppler using two ultrasound contrast agents (Levovist, Optison). Amount and architecture of lesion vascularity and the kinetics of contrast enhancement within the lesions were analyzed. Vascularity was detected in 61% of liver lesions (52/85) by conventional power Doppler, compared to 86% (73/85) by contrast-enhanced power Doppler sonography. Dynamic contrast-enhanced power Doppler identified arterial radial hypervascularity <16 s after contrast injection in 19/22 focal nodular hyperplasias (86%). Irregular hypervascularity was seen with contrast enhancement in the arterial phase in 14/15 hepatocellular carcinomas (93%). In 14/25 hemangiomas (56%), a circular vascularization pattern was noted. Specific lesion diagnosis based on B-scan and conventional and dynamic contrast-enhanced power Doppler sonography led to correct diagnosis in 86% (73/85, 95% confidence interval 78%-94%) compared to 57% (48/85, 95% confidence interval 47%-94%) by B-scan criteria and conventional power Doppler sonography. Contrast-enhanced power Doppler sonography improves diagnostic accuracy in the differential diagnosis of focal liver lesions.