Contrast-enhanced power Doppler sonography: Improved detection of characteristic flow patterns in focal liver lesions

Purpose. The aim of this study was to evaluate whether intravenous injectio n of an ultrasound contrast agent aids in the visualization of focal liver lesions on power Doppler images. Methods. Fifty patients with focal liver lesions were studied by B-mode and power Doppler sonography before and after intravenous injection of the con trast agent Levovist (galactose-based microbubbles; 10 mi of a concentratio n of 300 mg/ml). Thirty-two patients had malignant liver lesions (19 metast ases, 12 hepatocellular carcinomas, 1 cholangiocellular carcinoma), while 1 8 had benign lesions (12 hemangiomas, 2 focal nodular hyperplasias, 4 other s). Results. After contrast medium injection, the number of lesions with no int ralesional flow dropped from 18 to 9. Flow signal intensity was rated subje ctively as marked on contrast-enhanced images in 17 patients; only 4 patien ts had marked flow on precontrast images. On precontrast studies, central f low in 10 lesions and peripheral flow in 29 lesions could be observed. Afte r enhancement, the numbers increased to 18 and 34 lesions, respectively. Conclusions. On power Doppler images, a greater number of intratumoral vess els are seen in focal liver lesions after contrast medium administration. ( C) 1999 John Wiley & Sons, Inc.