MR Imaging of Hepatocellular Adenomas and Differential Diagnosis Dilemma

Figure 1

Inflammatory adenoma and focal nodular hyperplasia. (a) Axial T2w fat-suppressed image. In Segment (S) VII homogeneous well-delineated hyperintense adenoma (arrow), proven by biopsy. In SI, note a second isointense lesion, focal nodular hyperplasia (arrowhead). (b-c) T1w in- and out-phased images. Both lesions are mainly isointense. (d–i) DWI sequences. Adenoma (arrow in d) is constantly hyperintense. Conversely FNH (arrowhead in d) is isointense. ADC map (i) both lesions are is slightly hyperintense. (j–n) In dynamic evaluation after Gd-EOB-DTPA administration adenoma shows intense enhancement in arterial phase (k) with washout in portal (l) and equilibrium (m) phases; conversely, FNH shows progressive increase of the signal. (o-p) In hepatobiliary phases after 10′ (o) and 20′ (p), adenoma is hypointense relative to the adjacent liver parenchyma and FHN is hyperintense. (o) Histology shows hepatocytes arranged in plates that are two to three cells thick separated by sinusoids.

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