title: Three-dimensional contrast-enhanced hepatic MR imaging: comparison between a centric technique and a linear approach with partial Fourier along both slice and phase directions.
abstract: OBJECTIVE
  To compare the image quality of two variants of a three-dimensional (3D) gradient echo sequence (GRE) for hepatic MRI.
  
  
  METHODS
  Thirty-nine patients underwent hepatic MRI on a 3.0 Tesla (T) magnet (Intera Achieva; Philips Medical Systems). The clinical protocol included two variants of a 3D GRE with fat suppression: (i) a "centric" approach, with elliptical centric k-space ordering and (ii) an "enhanced" approach using linear sampling and partial Fourier in both the slice and phase encoding direction. "Centric" and "Enhanced" 3D GRE images were obtained both precontrast (n = 32) and after gadoxetic acid injection (n = 39). Two reviewers jointly reviewed MR images for anatomic sharpness, overall contrast, homogeneity, and absence of artifacts. The liver-to-lesion signal difference ratio (SDR) was measured. Paired sample Wilcoxon test and paired t-tests were used.
  
  
  RESULTS
  Enhanced 3D GRE images performed better than centric 3D GRE images with respect to anatomic sharpness (P = 0.0156), overall contrast (P = 0.0195), homogeneity (P < 0.0001), and absence of artifacts (P = 0.0003) on precontrast images. For postcontrast MRI, enhanced 3D GRE images showed better quality in terms of overall contrast (P = 0.0195), homogeneity (P < 0.0001), and absence of artifacts (P = 0.009). Liver-to-lesion SDR on enhanced 3D GRE images (0.48 ± 0.13) was significantly higher than that of conventional 3D GRE images (0.40 ± 0.19, P = 0.0004) on postcontrast images, but not on precontrast images.
  
  
  CONCLUSIONS
  The enhanced 3D GRE sequence available on our scanner provided better hepatic image quality than the centric variant, without compromising lesion contrast.
authors.affiliation: Department of Radiology, Hallym University Sacred Heart Hospital, College of Medicine, Gyeonggi-do, Korea.
authors.forename: Kyung Ah
authors.initials: KA
authors.lastname: Kim
authors.forename: Gwenael
authors.initials: G
authors.lastname: Herigault
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Chung
authors.forename: Hye-Suk
authors.initials: HS
authors.lastname: Hong
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D003198:Computer Simulation; D003287:Contrast Media; D005260:Female; D005583:Fourier Analysis; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D016014:Linear Models; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA