MRI findings of multiple focal nodular hyperplasia of the liver

Objective To assess the diagnostic value of MRI on multiple focal nodular hyperplasia (FNH) of the liver. Methods MR images of 9 cases with pathological-confirmed multiple FNH were retrospectively analyzed. MRI features of the lesions were correlated with pathological findings. Results Multiple FNH was considered in all these 9 cases. Among them, the primary diagnosis was FNH in 5,hepatic adenoma in 3 and fibrolamellar hepatocellular carcinoma in 1 case. A total of 31 lesions were detected in the 9 cases. On T2WI, 19 lesions presented slightly high-signal intensity, and the other 12 presented iso-signal intensity. On T1WI, 12 lesions presented slightly low-signal intensity, 7 presented iso-signal intensity, and the other 12 presented high-signal intensity. On opposed-phase, the signal intensity of 1 lesion dropped unevenly. After bolus injection of contrast agent Gd-DTPA, in hepatic arterial phase 18 lesions showed mild to marked heterogeneous enhancement, 11 showed marked homogeneous enhancement, 1 showed moderate ring-like enhancement, and the last one did not have obvious enhancement In portal venous and delayed phase, all the lesions turned to iso- or slightly high-signal intensity gradually. Sixteen of 31 lesions presented central scar, which demonstrated mild star-like enhancement in delayed phase. Conclusion Multiple FNH presented certain MRI features, which contributed to the preoperative diagnosis. Key words: Liver neoplasm;  Magnetic resonance imaging