title: Fat-suppressed, three-dimensional T1-weighted imaging using high-acceleration parallel acquisition and a dual-echo Dixon technique for gadoxetic acid-enhanced liver MRI at 3 T.
abstract: BACKGROUND
  Parallel imaging (PI) techniques are used for overcoming lower spatial and time resolution for magnetic resonance imaging (MRI). There is clinical need to overcome inevitable noise by decreased voxel size and signal-to-noise issue by using high-acceleration factor (AF).
  
  
  OBJECTIVE
  To determine whether the combination of a modified Dixon three-dimensional (3D) T1-weighted (T1W) gradient echo technique (mDixon-3D-GRE) and high-acceleration ([HA], AF = 5) PI can provide breath-hold (BH) T1W imaging with better image quality than conventional fat-suppressed 3D-T1W-GRE (SPAIR-3D-GRE) for Gd-EOB-DTPA-enhanced liver MR.
  
  
  METHODS
  This retrospective study was approved by our institutional review board and informed consent was waived. There were 138 patients who underwent Gd-EOB-DTPA-enhanced liver MR at 3 T using either standard SPAIR-3D-GRE sequences with an AF of 2.6 (n = 68, Standard group) or mDixon-3D-GRE with an AF of 5 (n = 70, HA group). In the HA group, hepatobiliary phase was obtained three times using HA-mDixon-3D-GRE (AF = 5), HA-SPAIR-3D-GRE (AF = 5), and standard-SPAIR-3D-GRE (AF = 2.6). Image noise, quality, and anatomic depiction of dynamic phase were compared between standard and HA groups, and those of hepatobiliary phase were compared among the three image sets in HA group.
  
  
  RESULTS
  As for dynamic imaging, the HA-mDixon-3D-GRE images showed better anatomic details and overall image quality than standard-SPAIR-3D-GRE sequence (arterial phase: 3.56 ± 0.63 vs. 2.66 ± 0.69, P < 0.001). In the intra-individual comparison, HA-mDixon-3D-GRE provided better orang depiction and overall image quality than standard-SPAIR-3D-GRE (3.99 ± 0.75 vs. 3.0 ± 0.72, P < 0.001) and better fat suppression and significantly less noise than HA-SPAIR-3D-GRE (4.76 ± 0.43 vs. 3.71 ± 0.54, P < 0.001).
  
  
  CONCLUSIONS
  The combined use of mDixon-3D-GRE sequence and high-acceleration PI provided better quality BH-T1W imaging compared with conventional SPAIR-3D-GRE for Gd-EOB-DTPA-enhanced liver MRI.
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea Institute of Radiation Medicine Seoul National University College of Medicine, Seoul, Republic of Korea JMSH@SNU.AC.KR.
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Konkuk University Hospital, Seoul, Republic of Korea.
authors.forename: Mi Hye
authors.initials: MH
authors.lastname: Yu
authors.affiliation: Philips Healthcare Korea, Seoul, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea Institute of Radiation Medicine Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Republic of Korea Institute of Radiation Medicine Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D008099:Liver / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: Liver; fat suppression; flexible echo time; three-dimensional spoiled gradient echo; two-point Dixon