title: Correction for heart rate variability improves coronary magnetic resonance angiography.
abstract: OBJECTIVE
  To address degradation of coronary MR angiography (MRA) image quality due to heart rate variability (HRV)-associated variations in coronary artery position and motion.
  
  
  METHODS
  Free-breathing navigator-gated and -corrected coronary MRA using subject-specific trigger delays and acquisition windows was combined with a real-time HRV correction algorithm, such as commonly used in left ventricular wall motion studies. Ten healthy adults underwent free-breathing navigator-gated and -corrected coronary MRA with and without HRV correction. Signal-to-noise (SNR), contrast-to-noise (CNR), vessel length, diameter, sharpness, and subjective image quality (on a five-point scale) were compared in a blinded fashion.
  
  
  RESULTS
  Vessel sharpness improved significantly for both the left (LCA) and right (RCA) coronary artery systems (P = 0.016 and P = 0.015, respectively) with the use of HRV correction. Subjective image quality also improved significantly when HRV correction was used (P = 0.003). There were no significant differences with regard to SNR and CNR (P > 0.1).
  
  
  CONCLUSIONS
  Preliminary results suggest that HRV correction improves objective and subjective image quality in coronary MRA. Continued studies in patients with known or suspected coronary artery disease are warranted to investigate the clinical impact of this technique.
authors.affiliation: Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA. leiner@rad.unimaas.nl
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
authors.forename: George
authors.initials: G
authors.lastname: Katsimaglis
authors.forename: Ernest N
authors.initials: EN
authors.lastname: Yeh
authors.forename: Kraig V
authors.initials: KV
authors.lastname: Kissinger
authors.forename: Gert
authors.initials: G
authors.lastname: van Yperen
authors.forename: Holger
authors.initials: H
authors.lastname: Eggers
authors.forename: Warren J
authors.initials: WJ
authors.lastname: Manning
authors.forename: René M
authors.initials: RM
authors.lastname: Botnar
mesh_terms: D000293:Adolescent; D000328:Adult; D003331:Coronary Vessels; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000592:standards*; D008297:Male