title: Correction for heart rate variability during 3D whole heart MR coronary angiography.
abstract: OBJECTIVE
  To evaluate the effect of a real-time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole-heart coronary MR angiography (MRA).
  
  
  METHODS
  Twelve healthy adults underwent 3D whole-heart coronary MRA with and without the use of an adaptive trigger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR-interval using physiological modeling. Signal-to-noise, contrast-to-noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner.
  
  
  RESULTS
  Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 +/- 7.1% versus 48.9 +/- 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay.
  
  
  CONCLUSIONS
  Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD.
authors.affiliation: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Stijntje D
authors.initials: SD
authors.lastname: Roes
authors.forename: Grigorios
authors.initials: G
authors.lastname: Korosoglou
authors.forename: Michael
authors.initials: M
authors.lastname: Schär
authors.forename: Jos J
authors.initials: JJ
authors.lastname: Westenberg
authors.forename: Matthias J P
authors.initials: MJ
authors.lastname: van Osch
authors.forename: Albert
authors.initials: A
authors.lastname: de Roos
authors.forename: Matthias
authors.initials: M
authors.lastname: Stuber
mesh_terms: D000328:Adult; D003331:Coronary Vessels; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D018709:Statistics, Nonparametric