MRI of focal nodular hyperplasia (FNH) with gadobenate dimeglumine (Gd-BOPTA) and SPIO (ferumoxides): An intra-individual comparison

Purpose To compare the efficacy of two different MR contrast agents for the detection and diagnosis of focal nodular hyperplasia (FNH). Materials and Methods Fifty patients with 83 FNH lesions detected on spiral CT were studied in two different MRI sessions with Gd-BOPTA (MultiHance®) and ferumoxides (Endorem®). MRI with Gd-BOPTA was performed precontrast (T1wGRE and T2wTSE sequences) and during the dynamic and late (1–3 hours) phases after injection (T1wGRE sequences only). MRI with ferumoxides (T1wGRE and T2wTSE sequences) was performed before and at least 30 minutes after injection. Hyper- or isointensity of FNH in the late phase was considered typical for Gd-BOPTA, while isointensity or lesion hypointensity was considered typical for ferumoxides. Results With Gd-BOPTA, 83 FNH lesions (100%) appeared hyperintense during the arterial phase of dynamic MRI. All but one lesion was iso- or slightly hyperintense in the portal-venous and equilibrium phases. In the late phase, 81 FNH lesions were hyper- or isointense to the surrounding parenchyma, with two lesions appearing slightly hypointense. With ferumoxides, a significant (P < 0.001) number (21/83, 25.3%) of FNH lesions (mean diameter = 16.8 ± 6.6 mm) were not visible. Of the visible FNH lesions, 38/62 were slightly hyperintense, and 24/62 were isointense to the surrounding parenchyma on the T2wTSE images. On the T1wGRE images, 42/62 lesions were isointense, 19/62 were slightly hyperintense, and one lesion was slightly hypointense. Seventeen lesions in 12 patients with previous neoplasia were all detected after Gd-BOPTA administration, whereas only nine of these 17 lesions (52.9%) were detected after ferumoxide administration. Two of these nine lesions showed atypical enhancement features. Conclusion Gd-BOPTA-enhanced MRI is significantly better than ferumoxide-enhanced MRI for the identification and characterization of FNH. J. Magn. Reson. Imaging 2003;17:593–602. © 2003 Wiley-Liss, Inc.