title: Feasibility of free-breathing late gadolinium-enhanced cardiovascular MRI for assessment of myocardial infarction: navigator-gated versus single-shot imaging.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility of two free-breathing late gadolinium-enhanced cardiovascular magnetic resonance (LGE-CMR) techniques (two-dimensional segmented navigator-gated [NAV-LGE] and single-shot [SS-LGE]) by comparing with breath-hold LGE-CMR (BH-LGE) as reference.
  
  
  METHODS
  A total of 200 consecutive patients underwent the three LGE-CMR imaging techniques. BH patterns were assessed with dynamic navigator MR imaging. Image quality was graded on a 5-point scale (4=optimal; 0=not assessable). In patients with sufficient BH capability (diaphragmatic movement with a deviation of <3mm), hyperenhancement was scored with a 5-point scale, and global infarct size (%left ventricle) was quantified.
  
  
  RESULTS
  Compared to free-breathing LGE-CMR, BH-LGE had higher image quality grade in patients with sufficient BH capability (P<0.01 [vs. NAV-LGE]; P<0.001 [vs. SS-LGE]) but poorer image quality in patients with insufficient BH capability (P<0.001 [vs. NAV-LGE]; P<0.01 [vs. SS-LGE]). NAV-LGE had higher sensitivity for infarct detection than SS-LGE (97.1% vs. 88.4%, P<0.05), but specificity was not significantly different (97.3% vs. 94.7%, P=0.37). By Bland-Altman analysis, the average differences in global infarct size were 0.4% and 1.2%, and the limits of agreement were ± 4.0% and ± 5.9% for NAV- and SS-LGE, respectively.
  
  
  CONCLUSIONS
  Although both NAV- and SS-LGE improve the image quality in patients with insufficient BH capability, NAV-LGE is superior to SS-LGE in infarct detection and infarct size measurement. NAV-LGE can be a possible first-line technique for patients with inability to perform sufficient BH.
authors.affiliation: Cardiovascular Center, Rakuwakai Otowa Hospital, Kyoto, Japan. matsumoto.hidenari@gmail.com
authors.forename: Hidenari
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Matsuda
authors.forename: Kenichi
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Kenji
authors.initials: K
authors.lastname: Nakatsuma
authors.forename: Masataka
authors.initials: M
authors.lastname: Sugahara
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Shimada
mesh_terms: D000368:Aged; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology*; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology*
chemical_list: D005682:Gadolinium