MRI of hepatic focal nodular hyperplasia: a report of two new cases in the pediatric age group.

At present, magnetic resonance is a useful modality for the diagnostic assessment of focal nodular hyperplasia of the liver. In the pediatric age group, diagnosis for this kind of pathology is more effective and conclusive when performed by MR, because of the limited variety and the restricted expression of primary hepatic tumors. MR diagnosis is based on the presence of a central connective tissue that is scar hyperintense on T2-weighted sequences, which can be regarded as a typical finding, though not specific. The other criteria used to differentiate it from primary malignant tumors on MRI are the homogeneity of the tissue surrounding the scar and its signal intensity, which is similar to that of adjacent normal hepatic parenchyma.