Focal nodular hyperplasia: hepatobiliary enhancement patterns on gadoxetic-acid contrast-enhanced MRI.
OBJECTIVE
To assess the range of hepatobiliary enhancement patterns of focal nodular hyperplasia (FNH) after gadoxetic-acid injection, and to correlate these patterns to specific histological features.


METHODS
FNH lesions, imaged with Gadoxetic-acid-enhanced MRI, with either typical imaging findings on T1, T2 and dynamic-enhanced sequences or histologically proven, were evaluated for hepatobiliary enhancement patterns and categorized as homogeneously hyperintense, inhomogeneously hyperintense, iso-intense, or hypo-intense-with-ring. Available histological specimens of FNHs (surgical resection or histological biopsy), were re-evaluated to correlate histological features with observed enhancement patterns.


RESULTS
26 FNHs in 20 patients were included; histology was available in six lesions (four resections, two biopsies). The following distribution of enhancement patterns was observed: 10/26 homogeneously hyperintense, 4/26 inhomogeneously hyperintense, 5/26 iso-intense, 6/26 hypointense-with-ring, and 1/26 hypointense, but without enhancing ring. The following histological features associated with gadoxetic-acid uptake were identified: number and type of bile-ducts (pre-existent bile-ducts, proliferation, and metaplasia), extent of fibrosis, the presence of inflammation and extent of vascular proliferation.


CONCLUSIONS
FNH lesions can be categorized into different hepatobiliary enhancement patterns on Gadoxetic-acid-enhanced MRI, which appear to be associated with histological differences in number and type of bile-ducts, and varying the presence of fibrous tissue, inflammation, and vascularization.
Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands. c.s.vankessel@umcutrecht.nl
C S
CS
van Kessel
E
E
de Boer
F J W
FJ
ten Kate
L A A
LA
Brosens
W B
WB
Veldhuis
M S
MS
van Leeuwen
D018952:Antigens, CD34 / Q000378:metabolism; D001659:Biliary Tract / Q000473:pathology; D003287:Contrast Media; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis* / Q000378:metabolism; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007150:Immunohistochemistry; D008099:Liver / Q000473:pathology; D008279:Magnetic Resonance Imaging
D018952:Antigens, CD34; D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA