title: Differentiating focal eosinophilic infiltration from metastasis in the liver with gadoxetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To determine the most useful findings of gadoxetic acid-enhanced 3.0 Tesla (T) MRI for differentiating focal eosinophilic infiltration (FEI) from hepatic metastasis with verification of their usefulness.
  
  
  METHODS
  Pathologically or clinically proven 39 FEIs from 25 patients and 79 hepatic metastases from 51 patients were included in the study. Gadoxetic acid-enhanced 3.0T MRI was performed in all cancer patients. Size differences measured between T2-weighted and hepatobiliary-phase images for lesions > 1 cm and morphologic findings (margin, shape, signal intensity on T1- and T2-weighted images, enhancement pattern on dynamic images, and target appearance on hepatobiliary-phase images) were compared between two groups via Student's t test as well as univariate and multivariate analyses. Diagnostic predictive values of two observers for differentiating two groups were assessed before (session 1) and after (session 2) recognition of results.
  
  
  RESULTS
  Mean size difference (2.1 mm) in FEIs between the two images was significantly greater than for metastases (0.7 mm) (p < 0.05). An ill-defined margin and isointensity on T1-weighted images were independently significant morphologic findings (p < 0.05) for differentiating the two groups. All observers achieved a higher diagnostic accuracy in session 2 (97% and 98%) than session 1 (92% and 89%) with statistical significance in observer 2 (p < 0.05). All observers had significantly higher sensitivities (95%) and negative predictive values (NPVs) (98%) in session 2 than in session 1 (sensitivity, 74% in two observers; NPV, 89% and 88%) (p < 0.05).
  
  
  CONCLUSIONS
  With the size change, an ill-defined margin and isointensity on T1-weighted images are the most useful findings for differentiating FEI from hepatic metastasis on gadoxetic acid-enhanced 3.0T MRI.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Seoul, Korea.
authors.forename: Mi Hee
authors.initials: MH
authors.lastname: Lee
authors.forename: Seong Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Heejung
authors.initials: H
authors.lastname: Kim
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D003287:Contrast Media; D003937:Diagnosis, Differential; D004802:Eosinophilia / Q000473:pathology*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA