title: Hepatic Angiomyolipoma Versus Hepatocellular Carcinoma in the Noncirrhotic Liver on Gadoxetic Acid-Enhanced MRI: A Diagnostic Challenge.
abstract: OBJECTIVE
  The purpose of this study is to describe the imaging characteristics of hepatic angiomyolipoma (AML) on gadoxetic acid-enhanced MRI and to identify imaging features that are helpful for differentiating it from hepatocellular carcinoma (HCC) in a noncirrhotic liver.
  
  
  METHODS
  We retrospectively identified 18 patients with pathologically proven hepatic AMLs who had undergone gadoxetic acid-enhanced MRI between 2008 and 2012. We randomly chose 36 patients with noncirrhotic liver who had a single HCC diagnosed radiologically during the same period. None of the HCCs was of the fibrolamellar variant. Two readers reviewed images in consensus to assess the lesion size, the presence of fat, signal intensity characteristics, enhancement profile, early draining veins, intratumoral vessels, and tumor capsules. The tumor-to-liver contrast ratios were measured. These features and the measurements were compared between the two groups.
  
  
  RESULTS
  AMLs are more commonly found in women (83.3%), whereas HCCs are more common in men (75%) (p < 0.01). The size of AMLs (3.4 cm) and HCCs (4.3 cm) did not differ significantly. Intratumoral fat was identified in both AMLs (50.0%) and HCCs (30.6%). The dynamic enhancement profile (arterial hypervascularity and hypointensity during the delayed phase) was similar qualitatively and quantitatively except for the portal phase. AMLs and HCCs differed significantly with regard to isointensity on DWI (16.7% vs 0.0%; p = 0.03), washout in the portal phase (61.1% vs 88.9%; p = 0.03), early draining veins (27.8% vs 2.8%; p = 0.01), intratumoral vessels (55.6% vs 22.2%; p = 0.03), and presence of capsule (11.1% vs 50.0%; p = 0.01).
  
  
  CONCLUSIONS
  On gadoxetic acid-enhanced MRI of noncirrhotic liver, AML is often indistinguishable from HCC on the basis of the enhancement profiles. Female sex and some imaging features including DWI could facilitate the differentiation.
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: So Jung
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Kyoung Won
authors.initials: KW
authors.lastname: Kim
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Hyoung Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Moon-Gyu
authors.initials: MG
authors.lastname: Lee
authors.affiliation: 2 Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eun Sil
authors.initials: ES
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D018207:Angiomyolipoma / Q000000981:diagnostic imaging* / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: MRI; angiomyolipoma; gadoxetic acid; hepatocellular carcinoma; imaging; liver