Focal nodular hyperplasia of the liver: imaging features with pathologic correlation

Objective: To evaluate the comprehensive imaging findings and diagnosis of focal nodular hyperplasia (FNH) of the liver. Methods: In 8 cases of FNH confirmed pathologically, the imaging features (US, CT, and MRI) were retrospectively reviewed and correlated with pathologic findings. Results: Retraction of liver capsule adjacent to FNH was observed in 3 cases. 5 cases of FNH with typical imaging features (iso-echo, iso-density, and iso-intensity on T1WI and T2WI or slightly high signal intensity on T2WI, strong enhancement on arterial phase and slight or obvious enhancement on portal venous phase, slightly delayed enhancement of the central scars) were diagnosed correctly before operation. Of 3 FNH with atypical imaging findings (low echo and density 3 cases, high signal intensity on T1WI 1 cases, high signal intensity on T2WI 2 cases, heterogeneous 1 cases, no scar 3 cases), 1 was diagnosed correctly, 2 mistaken for malignant tumors. Conclusions: A correct preoperative diagnosis of FNH is possible in the cases with the correlative imaging findings