title: Double-gated myocardial ASL perfusion imaging is robust to heart rate variation.
abstract: Cardiac motion is a dominant source of physiological noise (PN) in myocardial arterial spin labeled (ASL) perfusion imaging. This study investigates the sensitivity to heart rate variation (HRV) of double-gated myocardial ASL compared with the more widely used single-gated method.
  
  
  
  Double-gating and single-gating were performed on 10 healthy volunteers (n = 10, 3F/7M; age, 23-34 years) and eight heart transplant recipients (n = 8, 1F/7M; age, 26-76 years) at rest in the randomized order. Myocardial blood flow (MBF), PN, temporal signal-to-noise ratio (SNR), and HRV were measured.
  
  
  
  HRV ranged from 0.2 to 7.8 bpm. Double-gating PN did not depend on HRV, while single-gating PN increased with HRV. Over all subjects, double-gating provided a significant reduction in global PN (from 0.20 ± 0.15 to 0.11 ± 0.03 mL/g/min; P = 0.01) and per-segment PN (from 0.33 ± 0.23 to 0.21 ± 0.12 mL/g/min; P < 0.001), with significant increases in global temporal SNR (from 11 ± 8 to 18 ± 8; P = 0.02) and per-segment temporal SNR (from 7 ± 4 to 11 ± 12; P < 0.001) without significant difference in measured MBF.
  
  
  
  Single-gated myocardial ASL suffers from reduced temporal SNR, while double-gated myocardial ASL provides consistent temporal SNR independent of HRV. Magn Reson Med 77:1975-1980, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Physics and Astronomy, University of Southern California, Los Angeles, California, USA.
authors.forename: Hung Phi
authors.identifier: 0000-0002-8141-8630
authors.initials: HP
authors.lastname: Do
authors.affiliation: Department of Medicine, Division of Cardiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Yoon
authors.affiliation: Department of Medicine, Division of Cardiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Fong
authors.affiliation: Department of Radiology, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
authors.forename: Farhood
authors.initials: F
authors.lastname: Saremi
authors.affiliation: Department of Cardiothoracic Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, USA.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Barr
authors.affiliation: Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California, USA.
authors.forename: Krishna S
authors.initials: KS
authors.lastname: Nayak
mesh_terms: D000328:Adult; D000368:Aged; D003326:Coronary Circulation; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging* / Q000502:physiology*; D006339:Heart Rate; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009038:Motion; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009206:Myocardium / Q000473:pathology*; D059629:Signal-To-Noise Ratio; D013113:Spin Labels; D055815:Young Adult
chemical_list: D013113:Spin Labels
keywords: arterial spin labeling; cardiovascular magnetic resonance; heart rate variation; myocardial blood flow; myocardial perfusion imaging; physiological noise