title: Detection of small hepatocellular carcinoma: can gadoxetic acid-enhanced magnetic resonance imaging replace combining gadopentetate dimeglumine-enhanced and superparamagnetic iron oxide-enhanced magnetic resonance imaging?
abstract: OBJECTIVE
  To investigate whether gadoxetic acid-enhanced magnetic resonance imaging (MRI) has the diagnostic capability and sensitivity comparable to the combination of gadopentetate dimeglumine-enhanced MRI and superparamagnetic iron oxide-enhanced MRI (double-contrast MRI) in the detection of small hepatocellular carcinomas (HCCs).
  
  
  METHODS
  Forty-one patients with 56 HCCs (size range, 0.5-2.0 cm) who underwent gadoxetic acid-enhanced MRI and double-contrast MRI with a mean interval of 4 days (range, 3-9 days) were included in this study. HCCs were diagnosed by histology (n = 25) and imaging findings (n = 31). Two observers independently reviewed the gadoxetic acid set (unenhanced, early dynamic, and hepatocyte phase images) and the double-contrast MRI set, at an initial reading session, and then reached consensus. Diagnostic accuracy and sensitivity were evaluated using the alternative-free response receiver operator characteristic method.
  
  
  RESULTS
  Diagnostic accuracy (AZ) and sensitivity were similar for both image sets (0.955, 83.9% for gadoxetic acid set; 0.952, 80.4% for double-contrast MRI set) (P > 0.05). There were 5 and 3 HCCs that were verified only on the gadoxetic acid set and double-contrast MRI set, respectively. All 9 HCCs that were not verified on the gadoxetic acid set were assigned a low confidence rating of 1 or 2. However, 3 of the 11 HCCs, which were not verified on double-contrast MRI, were not seen even upon retrospective review.
  
  
  CONCLUSIONS
  Gadoxetic acid-enhanced MRI can replace double-contrast MRI for the detection of HCCs. Because all HCCs were delineated on gadoxetic acid-enhanced MRI, even with a low confidence rating, and 3 HCCs were not seen on double-contrast MRI, gadoxetic acid-enhanced MRI could be more advantageous than double-contrast MRI for HCC work-up.
authors.affiliation: Department of Diagnostic Radiology and Research Institute of Clinical Medicine, Chonbuk National University Hospital and Medical School, JeonJu, South Korea. jmyr@dreamwiz.com
authors.forename: Young Kon
authors.initials: YK
authors.lastname: Kim
authors.forename: Chong Soo
authors.initials: CS
authors.lastname: Kim
authors.forename: Young Min
authors.initials: YM
authors.lastname: Han
authors.forename: Gun
authors.initials: G
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D016001:Confidence Intervals; D003287:Contrast Media; D005260:Female; D052203:Ferrosoferric Oxide; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA; D052203:Ferrosoferric Oxide