title: Validation of diagnostic criteria using gadoxetic acid-enhanced and diffusion-weighted MR imaging for small hepatocellular carcinoma (<= 2.0 cm) in patients with hepatitis-induced liver cirrhosis.
abstract: BACKGROUND
  Gadoxetic acid and diffusion-weighted imaging (DWI) is increasingly used for the diagnosis of hepatocellular carcinoma (HCC). It is relevant to refine the diagnostic parameters for HCC, using state-of-the-art imaging techniques.
  
  
  OBJECTIVE
  To validate usefulness of magnetic resonance imaging (MRI) criteria with gadoxetic acid-enhanced MRI and DWI for diagnosis of small HCC by differentiation from dysplastic nodule (DN) or regenerative nodule (RN) in cirrhotic patients with strongly suspected small HCC.
  
  
  METHODS
  One hundred and eight patients with 102 HCCs and 29 benign nodules including 21 DNs and two large RNs (≤ 2.0 cm), and 40 patients with no HCC underwent gadoxetic acid-enhanced MRI and DWI. All patients also underwent MDCT. Index MR criteria for HCC were: (i) arterial hyperenhancement and hypointensity on hepatobiliary phase (HBP) with hyperintensity on DWI; (ii) hypovascular nodule with hyperintensity on DWI; (iii) arterial hyperenhancement and hypointensity on HBP without hyperintensity on DWI; (iv) arterial hyperenhancement and either iso- or hyperintensity on HBP, with hyperintensity on DWI; and (v) hyperintensity only on DWI. According to these criteria, MRI findings for HCCs and benign nodules were independently classified by two reviewers.
  
  
  RESULTS
  On multidetector-row computed tomography, 64 HCCs (62.7%) showed typical features for HCC while 13 (12.8%) were not identified. On MRI, 84 HCCs (82.4%) showed arterial hyperenhancement and hypointensity on HBP, and hyperintensity on DWI. Eight HCCs were regarded as hypovascular HCCs with hyperintensity DWI (category 2). One HCC (0.6 cm in diameter) was demonstrated only by DWI. For each observer, 101 (99.0%) and 100 HCCs (98.0%) were discernible when applying all MRI criteria for HCC, respectively. Three DNs also fit the HCC criteria, thus the specificity was 90.9% for both observers.
  
  
  CONCLUSIONS
  With the HCC criteria based on combined gadoxetic acid-enhanced MRI and DWI, it is possible to reliably diagnose small HCC including hypovascular HCCs.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Park
authors.forename: Young Kon
authors.initials: YK
authors.lastname: Kim
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Lee
authors.forename: Jiyoung Hwang Won Jae
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000209:etiology*; D002908:Chronic Disease; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA; D006525:Hepatitis, Viral, Human / Q000150:complications*; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications* / Q000175:diagnosis / Q000821:virology*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D015588:Observer Variation; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA