title: Focal eosinophilic infiltration of the liver: gadoxetic acid-enhanced magnetic resonance imaging and diffusion-weighted imaging.
abstract: OBJECTIVE
  Using gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI), the purpose of this study was to evaluate findings of focal hepatic eosinophilic infiltration.
  
  
  METHODS
  This retrospective study included 8 patients with 7 histologically confirmed focal eosinophilic infiltration (FEI) of the liver. One case was considered as FEI by using clinical findings and follow-up imaging. Gadoxetic acid-enhanced MRI and DWI were reviewed by 2 radiologists. We evaluated the signal intensity of focal lesions on T1-weighted, T2-weighted, and DW images and the pattern of enhancement in arterial, portal, equilibrium, and hepatobiliary phases of the gadoxetic acid-enhanced MRI. Apparent diffusion coefficient (ADC) value for focal eosinophilic infiltration was also calculated.
  
  
  RESULTS
  On T2-weighted images, 7 (88%) of 8 cases (7/8 lesions) showed mixed hyperintensity with irregular margins. Six (75%) of the 8 cases showed rim enhancement in the arterial phase. Most cases (5/8 lesions [63%]) showed isointensity or hypointensity in the portal and equilibrium phases. In the hepatobiliary phase, all cases (8/8) showed mixed hypointensity with irregular margins and nonspherical shapes. All cases showed hyperintensity in both low and high b-value ranges on DWI. The ADCs for 6 cases showed less than 1.05 × 10(-3) mm2/s (0.74 × 10(-3) to 1.03 × 10(-3) mm2/s).
  
  
  CONCLUSIONS
  Focal eosinophilic infiltration showed mixed hypointensity, irregular margins, and nonspherical shapes with excellent lesion-to-liver contrast in the hepatobiliary phase of the gadoxetic acid-enhanced MRI. Diffusion-weighted imaging and ADCs may not be helpful for characterizing these benign hepatic lesions.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University Health System, Seoul, Korea.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Ahn
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Kyung Ah
authors.initials: KA
authors.lastname: Kim
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Song-Ee
authors.initials: SE
authors.lastname: Baek
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Ho-Taek
authors.initials: HT
authors.lastname: Song
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D038524:Diffusion Magnetic Resonance Imaging; D004802:Eosinophilia / Q000175:diagnosis*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008107:Liver Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA