Characterization of hepatic adenoma and focal nodular hyperplasia with gadoxetic acid.
OBJECTIVE
To characterize imaging features of histologically proven hepatic adenoma (HA) as well as histologically and/or radiologically proven focal nodular hyperplasia (FNH) using delayed hepatobiliary MR imaging with 0.05 mmol/kg gadoxetic acid.


METHODS
Five patients with six HAs with histological correlation were retrospectively identified on liver MRI studies performed with gadoxetic acid, and T1-weighted imaging acquired during the delayed hepatobiliary phase. Additionally, 23 patients with 34 radiologically diagnosed FNH lesions (interpreted without consideration of delayed imaging) were identified, two of which also had histological confirmation. Signal intensity ratios relative to adjacent liver were measured on selected imaging sequences.


RESULTS
All six hepatic adenomas (100%), which had histological confirmation, demonstrated hypointensity relative to adjacent liver on delayed imaging. Furthermore, all of the FNH (including 34 radiologically proven, 2 of which were also histologically proven) were either hyperintense (23/34, 68%) or isointense (11/34, 32%) relative to the adjacent liver on delayed imaging. None of the FNHs were hypointense relative to liver.


CONCLUSIONS
Distinct imaging characteristics of HA versus FNH on delayed gadoxetic acid-enhanced MRI, with adenomas being hypointense and FNH being iso- or hyperintense on delayed imaging may improve specificity for characterization, and aid in the differentiation of these two lesions.
Department of Radiology, University of Wisconsin, 600 Highland Ave., Madison, WI 53792, USA.
Kiyarash
K
Mohajer
Alex
A
Frydrychowicz
Jessica B
JB
Robbins
Agnes G
AG
Loeffler
Thomas D
TD
Reed
Scott B
SB
Reeder
D000236:Adenoma / Q000473:pathology*; D000328:Adult; D003287:Contrast Media; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000473:pathology*; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA