Triphasic dynamic CT findings of 63 hepatic focal nodular hyperplasia in 46 patients: correlation with size and pathological findings

Background: To correlate the dynamic computed tomography (CT) of hepatic focal nodular hyperplasia (FNH) with its size and pathology. Methods: The clinical data, pathological and dynamic CT findings of 36 FNHs in 24 males and 27 lesions in 22 females were reviewed. The pathological and CT findings of the 32 small FNHs (diameter < 3 cm) and 31 large FNHs (diameter >= 3 cm) were compared and analyzed. Results: All FNHs were hypervascular at arterial phase except for central scarring. The mean diameter of FNHs with hypoattenuating, isoattenuating, hyperattenuating on delayed scans were 5.05 cm, 3.06 cm, and 2.70 cm, respectively (p = 0.026). As compared with small FNHs, large ones were significantly more likely to reveal central scarring (p = 0.005), vascular displacement (p < 0.001), and abnormal vessels around lesions (p < 0001). Coexistent bile ductile proliferation and bridging septa were more commonly observed in small FNHs (p = 0.028 for both). FNHs without aberrant vessels tended to feature hyperattenuating during the portal venous phase (p = 0.041). Conclusions: FNHs with different tumor sizes may manifest various dynamic CT findings that are more or less related to the different pathological findings.