title: Image Non-Uniformity Correction for 3-T Gd-EOB-DTPA-Enhanced MR Imaging of the Liver.
abstract: OBJECTIVE
  Image non-uniformity may cause substantial problems in magnetic resonance (MR) imaging especially when a 3-T scanner is used. We evaluated the effect of image non-uniformity correction in gadolinium ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MR imaging using a 3-T scanner.
  
  
  METHODS
  Two commercially available methods for image non-uniformity correction, surface coil intensity correction (SCIC), and phased-array uniformity enhancement (PURE), were applied to Gd-EOB-DTPA-enhanced images acquired at 3-T in 20 patients. The calibration images were used for PURE and not for SCIC. Uniformity in the liver signal was evaluated visually and using histogram analysis. The liver-to-muscle signal ratio (LMR) and liver-to-spleen signal ratio (LSR) were estimated, and the contrast enhancement ratio (CER) was calculated from the liver signal, LMR, and LSR.
  
  
  RESULTS
  Without non-uniformity correction, hyperintensity was consistently observed near the liver surface. Both SCIC and PURE improved uniformity in the liver signal; however, the superficial hyperintensity remained after the application of SCIC, especially in the hepatobiliary-phase images, and focal hyperintensity was shown in the lateral segment of the left hepatic lobe after the application of PURE. PURE increased LMR dramatically and LSR mildly, with no changes in CERs. SCIC depressed temporal changes in LMR and LSR and obscured contrast effects, regardless of the method used for calculation of CER.
  
  
  CONCLUSIONS
  SCIC improves uniformity in the liver signal; however, it is not suitable for a quantitative assessment of contrast effects. PURE is indicated to be a useful method for non-uniformity correction in Gd-EOB-DTPA-enhanced MR imaging using a 3-T scanner.
authors.affiliation: Department of Diagnostic Radiology, Kitasato University School of Medicine.
authors.forename: Gou
authors.initials: G
authors.lastname: Ogasawara
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Inoue
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsunaga
authors.forename: Kaoru
authors.initials: K
authors.lastname: Fujii
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Hata
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takato
mesh_terms: D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; 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