Contrast media-enhanced power Doppler sonography for evaluation of hemangiomas and malignant tumors in the liver

Aim: To evaluate the characterization of liver hemangiomas and malignant tumors using power Doppler sonography before and after intravenous injection of a sonocontrast agent. Methods: Forty-five patients with 57 liver tumors (22 hemangiomas, 24 metastases, 10 hepatocellular carcinomas (HCC) and one cholangiocellular carcinoma) were examined prospectively. The distribution (peripheral, central, mosaic) and extent (none, minimal, moderate and strong) of intratumoral flow pattern in each sonographic examination was subjectively classified. Results: The administration of the sonocontrast agent by bolus injection caused enhancement to gradually increase up to 2 min and lasted for 4-5 min. After injection of contrast agent, flow signals appeared or increased in 34 tumors. No signal enhancement was observed in 18 hemangiomas, four metastases and one HCC. The sensitivity and specificity of intratumoral vascularity for the detection of malignant liver tumors was 37.1 and 90.9% for unenhanced power Doppler sonography, and 85.7 and 81.8% for contrast-enhanced power Doppler sonography, respectively. Conclusion: Contrast-enhanced power Doppler sonography is superior to unenhanced power Doppler sonography in the demonstration of malignant tumor vascularity, and is helpful in differentiating between hemangiomas and malignant liver tumors. A specific flow pattern within the tumor is not established in primary and metastatic malignant tumors with contrast-enhanced power Doppler sonography. (C) 2003 Blackwell Publishing Asia Pty Ltd.