DIFFERENTIATION OF HEPATOCELLULAR ADENOMA AND FOCAL NODULAR HYPERPLASIA OF THE LIVER - COMPARISON OF POWER DOPPLER IMAGING AND CONVENTIONALCOLOR DOPPLER SONOGRAPHY

The aim of our study was to compare the diagnostic efficacy of pou-er Doppler imaging and conventional color Doppler sonography for differen tiating between hepatocellular adenoma (HCA) and focal nodular hyperpl asia (FNH) of the liver. Thirty one focal liver lesions (in 29 patient s) with histologic proof of PICA (ri = 9) or FNH (ri = 22) were studie d with power and color Doppler sonograph! according to a standardized examination protocol. The size of the lesions ranged between 1.5 and 1 4.5 cm (HCA, 3.5-14.5 cm, mean +/- SD 7.3 +/- 3.3 cm; FNH, 1.5-9.1 cm, mean +/- :SD 5.1 +/- 2.1 cm). Intratumoral vessels with a venous Dopp ler spectrum, associated with either pulsatile or continuous periphera l flow, were detected in PICA (eight of nine lesions by pou er Doppler imaging and six of nine by color Doppler imaging) but not in FNH. In contrast, color signals with an arterial Doppler spectrum, radiating f rom the center to the periphery of the lesion, were depicted in FNH (2 0 of 22 cases by power Doppler imaging and 15 of 22 by color Doppler s onography) but not in PICA. Differentiation of PICA and FNH was achiev ed in 28 of 31 cases (90 %) by power Doppler imaging and in 31 of 31 ( 68 %) by color Doppler sonography (p < 0.01). Power Doppler imaging is superior to conventional color Doppler sonography in the depiction of the intratumoral flow characteristics of HCA and FNH, and enables a m ore accurate differential diagnosis than color Doppler sonography.