QUANTITATIVE PERFUSION PARAMETERS OF FOCAL NODULAR HYPERPLASIA AND NORMAL LIVER PARENCHYMA AS DETERMINED BY ELECTRON-BEAM TOMOGRAPHY

Eight patients with known focal nodular hyperplasia (FNH) were studied by electron beam tomography (EBT) in a multisection flow mode al defi ned time intervals after intravenous contrast agent injection. Various regions of interest (ROIs) were defined in the areas of FNH, normal l iver parenchyma, aorta and portal vein. In each ROI density changes we re measured and plotted against time. In those time-density curves (TD Cs) the slope, the time of maximal enhancement and the absolute densit y value of peak enhancement were determined. Arterial tissue perfusion was calculated for normal liver parenchyma and FNH. In all eight pati ents significant differences in peak density (123.88 +/- 18.92 HU vs 1 02.5 +/- 15.49 HU, p = 0.012), in the rate of arterial contrast enhanc ement (252.63 +/- 28.05 HU min(-1) as 38.88 +/- 4.19 HU min(-1), p = 0 .012) and in the arterial tissue perfusion (1.36 +/- 0.19 ml min(-1) c m(-3) vs 0.21 +/- 0.03 ml min(-1) cm(-3), p = 0.012) between FNH and n ormal liver parenchyma were found. Perfusion values of normal liver pa renchyma correspond to those determined by inert gas clearance. Furthe r studies will determine the practicability of this quantitative metho d in the evaluation of global and other focal liver diseases.