title: Respiratory bellows-gated late gadolinium enhancement of the left atrium.
abstract: OBJECTIVE
  To compare bellows-gated late gadolinium enhancement (LGE) with standard navigator-gated (NAV-gated) LGE for left atrial (LA) imaging, to eliminate the inflow artifacts associated with NAV-gating.
  
  
  METHODS
  Eleven subjects, including six patients with atrial fibrillation (AF), were imaged with a 3D free-breathing NAV-gated and bellows-gated LGE. Motion compensation was compared by blinded grading of image sharpness and motion ghosting (0 = worst, 2 = best). Inflow artifacts in the right inferior pulmonary vein (RIPV) and right superior PV (RSPV) were characterized on the same scale (0 = none, 2 = prominent). In patients, each PV was divided into four quadrants circumferentially in order to assess agreement about scar presence on both image sets.
  
  
  RESULTS
  Respiratory compensation was not different (1.7 ± 0.5 vs. 1.6 ± 0.5, sharpness, 1.6 ± 0.5 vs. 1.6 ± 0.5, ghosting, P = NS) for bellows- and NAV-gated images. For NAV-gated LGE, inflow artifacts were more prominent in the RSPV than the RIPV (1.2 ± 0.8 vs. 0.7 ± 0.5, P = 0.046). Visually, inflow artifacts both obscured and mimicked the true scar. Disagreement on the presence of scar was found in 18% of the assessed quadrants, with 25% disagreement for RSPV quadrants (P = 0.01).
  
  
  CONCLUSIONS
  Bellows-gated LGE provides similar respiratory compensation as NAV-gating, without inflow artifacts, leading to improved assessment of scar presence.
authors.affiliation: Beth Israel Deaconess Medical Center, Department of Medicine (Cardiovascular Division), Boston, Massachusetts, USA; Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA; Department of Diagnostic Radiology, Yale Medical School, New Haven, Connecticut, USA.
authors.forename: Dana C
authors.initials: DC
authors.lastname: Peters
authors.forename: Jaime L
authors.initials: JL
authors.lastname: Shaw
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Knowles
authors.forename: Mehdi Hedjazi
authors.initials: MH
authors.lastname: Moghari
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
mesh_terms: D001281:Atrial Fibrillation / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA