title: Accuracy of visual analysis vs. apparent diffusion coefficient quantification in differentiating solid benign and malignant focal liver lesions with diffusion-weighted imaging.
abstract: OBJECTIVE
  The authors compared the accuracy of diffusion-weighted imaging (DWI) visual analysis (VA) vs. apparent diffusion coefficient quantification (ADC-Q) in assessing malignancy of solid focal liver lesions (FLLs).
  
  
  METHODS
  Using a 1.5-T system, two radiologists retrospectively assessed as benign or malignant 50 solid FLLs: (a) by VA of signal intensity on DWI images at b=800 s/mm(2) and ADC map; (b) by quantifying lesion ADC. Reference standard included histology or follow-up confirmation of diagnosis by a consensus panel. Receiver operating characteristic (ROC) curve analysis was performed.
  
  
  RESULTS
  because of 20 false-negative hepatocellular carcinomas, VA showed lower accuracy than ADC-Q (52.0% VS. 68.0%). however, stratified accuracy for metastases was higher with VA (75.0 VS. 66%). ADC and signal features of malignant and benign FLLs were found to largely overlap.
  
  
  CONCLUSIONS
  VA performed worse than ADC-Q for hepatocellular carcinoma and better for metastases. Overall, the accuracy of both methods was limited because of the overlap in visual appearance and ADC values between solid benign and malignant FLLs.
authors.affiliation: Institute of Diagnostic Radiology, University of Udine, Azienda Ospedaliero-Universitaria "S. Maria della Misericordia", Udine, Italy. rgirometti@sirm.org
authors.forename: R
authors.initials: R
authors.lastname: Girometti
authors.forename: M
authors.initials: M
authors.lastname: Del Pin
authors.forename: S
authors.initials: S
authors.lastname: Pullini
authors.forename: L
authors.initials: L
authors.lastname: Cereser
authors.forename: G
authors.initials: G
authors.lastname: Como
authors.forename: M
authors.initials: M
authors.lastname: Bazzocchi
authors.forename: C
authors.initials: C
authors.lastname: Zuiani
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000473:pathology; D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005188:False Negative Reactions; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis / Q000473:pathology; D006391:Hemangioma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric