title: Detection of small hepatocellular carcinoma using gadoxetic acid-enhanced MRI: Is the addition of diffusion-weighted MRI at 3.0T beneficial?
abstract: OBJECTIVE
  To determine whether adding diffusion-weighted imaging (DWI) to gadoxetic acid-enhanced 3.0T magnetic resonance imaging (MRI) can improve the detection of hepatocellular carcinoma (HCC), particularly for small lesions (≤2 cm) in patients with liver cirrhosis.
  
  
  METHODS
  Data of patients diagnosed with focal liver lesions who had undergone gadoxetic acid-enhanced 3.0T MRI and DWI were retrospectively reviewed. Two radiologists (the observers) reviewed independently MRI images in two reading sessions, that is, gadoxetic acid-enhanced images alone and the combination of DWI (b values: 0 and 600 s/mm(2) ) and gadoxetic acid-enhanced images. They assigned to each lesion a confidence level based on a five-point scale. The area under the receiver operating characteristic curve (AUROC), sensitivity and positive predictive value (PPV) for the detection of HCC were calculated.
  
  
  RESULTS
  Both observers found the AUROC of the gadoxetic acid-enhanced images was slightly higher than that of the combined DWI and gadoxetic acid-enhanced MRI images in the detection of HCC (observer 1: 0.947 ± 0.030 vs 0.896 ± 0.042, Z = 1.478, P = 0.139; observer 2: 0.917 ± 0.038 vs 0.868 ± 0.048, Z = 1.296, P = 0.195). The sensitivity for the gadoxetic acid set alone was slightly higher than that for the combined set for observer 1 (97% vs 84%) and slightly lower for observer 2 (74% vs 82%). The PPVs were slightly higher for the gadoxetic acid set alone than for the combined set for both observers (observer 1, 89% vs 80%; observer 2, 93% vs 78%); however, none of the differences were statistically significant (P > 0.05).
  
  
  CONCLUSIONS
  There is no benefit in adding DWI to gadoxetic acid-enhanced MRI for the detection of HCC at 3.0T.
authors.affiliation: Department of Radiology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Xiang Tian
authors.initials: XT
authors.lastname: Zhao
authors.forename: Wei Xia
authors.initials: WX
authors.lastname: Li
authors.forename: Wei Min
authors.initials: WM
authors.lastname: Chai
authors.forename: Ke Min
authors.initials: KM
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D055088:Early Detection of Cancer / Q000379:methods; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: diffusion magnetic resonance imaging; early diagnosis; gadoxetic acid; hepatocellular carcinoma; magnetic resonance imaging