Contrast-enhanced, wide-band phase-inversion power Doppler imaging of hepatic focal nodular hyperplasia.

Background/aims: To determine whether examination of hepatic focal nodular hyperplasia by wide-band, phase-inversion sonography offers any advantages over power and color Doppler sonography in the depiction of specific characteristics of these pathologies.

Methodology: Twenty-six patients were examined. The presence of focal nodular hyperplasia was confirmed by ultrasound-guided biopsy, surgical resection, dynamic helical computed tomography or magnetic resonance. All patients, prior to enhanced sonography, had undergone B-mode gray-scale sonography, color Doppler, and power Doppler examinations. After injection of 2.5 g of Levovist intravenously, analysis of the contrast agent arrival was performed by wide-band, phase-inversion power Doppler sonography.

Results: The B-mode gray-scale sonography, color and power Doppler sonography were non-specific for focal nodular hyperplasia in 14 cases in our examination. However based on the wide-band, phase-inversion power Doppler sonography findings all patients with focal nodular hyperplasia were diagnosed. All typical anatomic features of focal nodular hyperplasia such as "star sign" or "spoke-wheel" pattern were clearly visible. In 3 cases, computed tomography and magnetic resonance imaging had failed to disclose pathology while phase-inversion sonographic images were completely suggestive which was later finally confirmed by histologic examination.

Conclusions: Our data demonstrate the usefulness of wide-band, phase-inversion power Doppler sonography in the differential diagnosis of hepatic focal nodular hyperplasia by visualizing all characteristic anatomic details.