Multi-slice CT and MRI in the Diagnosis of Hepatic Focal Nodular Hyperplasia

Objective:To study the CT and MRI manifestations and their value in the diagnosis of hepatic focal nodular hyperplasia (FNH).Methods:The CT and MRI findings of FNH in 11 patients were analyzed retrospectively.All patients underwent 16-detector row spiral CT and MR scanning with and without contrast enhancement.Results:On plain CT,all lesions showed slightly low density,one patient had fatty liver background,the FNH lesion showed relatively high density.With contrast administration,the lesions showed intense and homogeneous enhancement during arterial phase,except for 8 lesions with the central scar which didn′t show obvious enhancement.Tortuous and dilated arteries were detected in 2 lesions.During portal vein phase and delayed phase,lesions remained slightly hyper-/ iso-/ hypo-attenuated when compared with the surrounding liver parenchyma.The central scar demonstrated delayed enhancement.On MR imaging,all 11 lesions showed slightly hypo-or iso-intensity on T1WI and slightly hyper-intensity on T2WI.After contrast administration,lesions showed marked enchancement on arterial phase,slightly hyper-intensity or iso-intensity on portal as well as delayed phase.Central scars showed delayed enhancement in all of the 11 lesions.1 patient had MR spectroscopy,showing marked increase of Cho peak.4 patients had diffuse weighted imaging,showing slightly hyper-intensity or iso-intensity of the lesions.Iso-/slightly hypo-signal intensity were shown on ADC images.Conclusion:MRI displays the pathologic characteristics of FNH better than CT,DWI and MRS provide important supplementary information for the diagnosis.