USEFULNESS OF NOVEL IMAGING MODALITIES IN DIAGNOSIS OF FOCAL NODULAR HYPERPLASIA OF THE LIVER

A 17-year-old woman was admitted because of a liver tumor found incide ntally by ultrasonography. Liver function was normal and there were no markers of hepatitis viruses or malignancy. Abdominal ultrasonography , computed tomography (CT), and magnetic resonance imaging revealed a mass (2cm in diameter) in the lateral segment of the left lobe of the liver. The lesion was not detected by hepatic arteriography. However, dynamic CT with fast scanning and dynamic CO2-enhanced ultrasonography demonstrated initial central enhancement of the mass followed by cent rifugal spread of enhancement to the periphery. Color Doppler how imag ing detected a central color spot, shown to be an artery by a pulsed D oppler spectrum analysis. Fine-needle biopsy confirmed a diagnosis of focal nodular hyperplasia. Dynamic CT with fast scanning, dynamic CO2- enhanced ultrasonography, and color Doppler flow imaging were useful i n detecting the vascular pattern specific to focal nodular hyperplasia . Investigation of further cases with these novel imaging modalities s hould help to establish a comprehensive diagnostic procedure and thus avoid unnecessary surgery for focal nodular hyperplasia, which is a co mpletely benign lesion.