title: Differentiating hepatocellular carcinoma from dysplastic nodules at gadobenate dimeglumine-enhanced hepatobiliary-phase magnetic resonance imaging.
abstract: OBJECTIVE
  We evaluated whether the addition of delayed phase imaging (DPI) gadobenate dimeglumine-enhanced MRI to dynamic postcontrast imaging improves the characterization of small hepatocellular carcinoma (HCC) and the differentiation between HCC, high grade dysplastic nodules (HGDN), and low grade dysplastic nodules (LGDN).
  
  
  METHODS
  Twenty-five cirrhotic patients with 30 nodules (16 HCC, 8 HGDNs, and 6 LGDNs; maximum size of 3 cm) were included in this retrospective study. The diagnostic reference standard was histology. All the patients underwent MRI both prior to and following intravenous administration of gadobenate dimeglumine. The lesions were classified as hypointense, isointense, hyperintense on DPI for qualitative assessment. In the quantitative analysis the relative tumor-liver contrast to noise ratio (CNR) of the lesions on DPI was calculated.
  
  
  RESULTS
  All HCCs were hypointense on DPI while only 8 (57.1%) of 14 DNs were hypointense and only 1 of 6 (16.6%) LGDNs was hypointense. There was a statistically significant difference in the hypointensity on DPI between HCCs and DNs (p = 0.003) in the qualitative analysis but not in the CNR values while there was a strong statistically significant difference in the hypointensity on DPI in the qualitative (p = 0.00001) and quantitative analysis (p < 0.05) between LGDNs and the group obtained by unifying HGDNs and HCCs.
  
  
  CONCLUSIONS
  DPI is helpful in differentiating HCCs and HGDNs from LGDNs. Demonstration of hypointensity on DPI should raise the suspicion of HGDN or hypovascular HCC in the case of nodules with atypical dynamic pattern.
authors.affiliation: Department of Bioimaging and Radiological Sciences, Institute of Radiology, Agostino Gemelli Hospital, Catholic University of The Sacred Heart, 8, Largo A. Gemelli, 00168, Rome, Italy. agatto79@gmail.com
authors.forename: A
authors.initials: A
authors.lastname: Gatto
authors.forename: A M
authors.initials: AM
authors.lastname: De Gaetano
authors.forename: M
authors.initials: M
authors.lastname: Giuga
authors.forename: M
authors.initials: M
authors.lastname: Ciresa
authors.forename: L
authors.initials: L
authors.lastname: Siciliani
authors.forename: L
authors.initials: L
authors.lastname: Miele
authors.forename: L
authors.initials: L
authors.lastname: Riccardi
authors.forename: F
authors.initials: F
authors.lastname: Pizzolante
authors.forename: G L
authors.initials: GL
authors.lastname: Rapaccini
authors.forename: A
authors.initials: A
authors.lastname: Gasbarrini
authors.forename: F
authors.initials: F
authors.lastname: Giuliante
authors.forename: F M
authors.initials: FM
authors.lastname: Vecchio
authors.forename: M
authors.initials: M
authors.lastname: Pompili
authors.forename: L
authors.initials: L
authors.lastname: Bonomo
mesh_terms: D000368:Aged; D062005:Biopsy, Large-Core Needle; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D009942:Organometallic Compounds
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine