title: Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire.
abstract: BACKGROUND
  Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire. A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning.
  
  
  METHODS
  A retrospectively-gated breath-hold spiral phase velocity mapping sequence (TR 19 ms) was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography. Cardiovascular magnetic resonance (CMR) velocity-time curves were processed semi-automatically and compared with corresponding invasive Doppler data.
  
  
  RESULTS
  When corrected for differences in heart rate between the two studies, CMR mean velocity through the cardiac cycle, peak systolic velocity (PSV) and peak diastolic velocity (PDV) were approximately 40 % of the peak Doppler values with a moderate - good linear relationship between the two techniques (R(2): 0.57, 0.64 and 0.79 respectively). CMR values of PDV/PSV showed a strong linear relationship with Doppler values with a slope close to unity (0.89 and 0.90 for right and left arteries respectively). In individual vessels, plots of CMR velocities at all cardiac phases against corresponding Doppler velocities showed a consistent linear relationship between the two with high R(2) values (mean +/-SD: 0.79 +/-.13).
  
  
  CONCLUSIONS
  High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow.
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. j.keegan@rbht.nhs.uk.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Keegan
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. c.raphael@rbht.nhs.uk.
authors.forename: Claire E
authors.initials: CE
authors.lastname: Raphael
authors.affiliation: Department of Bioengineering, Imperial College London, London, UK. k.parker@imperial.ac.uk.
authors.forename: Kim
authors.initials: K
authors.lastname: Parker
authors.affiliation: Radiological Physics, University Medical Centre, Freiburg, Germany. robin.simpson@uniklinik-freiburg.de.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Simpson
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. stephen.strain@yahoo.co.uk.
authors.forename: Stephen
authors.initials: S
authors.lastname: Strain
authors.affiliation: National Heart and Lung Institute, Imperial College London, London, UK. r.desilva@imperial.ac.uk.|Department of Cardiology, Royal Brompton and Harefield NHS Foundation Trust, London, UK. r.desilva@imperial.ac.uk.
authors.forename: Ranil
authors.initials: R
authors.lastname: de Silva
authors.affiliation: Department of Cardiology, Royal Brompton and Harefield NHS Foundation Trust, London, UK. c.dimario@rbht.nhs.uk.
authors.forename: Carlo
authors.initials: C
authors.lastname: Di Mario
authors.affiliation: Department of Cardiology, Chelsea and Westminster Hospital, London, UK. Julian.collinson@chelwest.nhs.uk.
authors.forename: Julian
authors.initials: J
authors.lastname: Collinson
authors.affiliation: Institue of Cardiovascular Science and Medicine, Liverpool Heart and Chest Hospital, Liverpool, UK. rod.stables@lhch.nhs.uk.
authors.forename: Rod H
authors.initials: RH
authors.lastname: Stables
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. r.wage@rbht.nhs.uk.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Wage
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. p.drivas@rbht.nhs.uk.
authors.forename: Peter
authors.initials: P
authors.lastname: Drivas
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. msugathapala@gmail.com.
authors.forename: Malindie
authors.initials: M
authors.lastname: Sugathapala
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. s.prasad@rbht.nhs.uk.
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Prasad
authors.affiliation: Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, UK. d.firmin@imperial.ac.uk.|National Heart and Lung Institute, Imperial College London, London, UK. d.firmin@imperial.ac.uk.
authors.forename: David N
authors.initials: DN
authors.lastname: Firmin
mesh_terms: D000328:Adult; D000368:Aged; D001331:Automation; D001783:Blood Flow Velocity; D062485:Breath Holding; D062906:Cardiac Catheters; D055424:Cardiac-Gated Imaging Techniques; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology*; D015150:Echocardiography, Doppler / Q000295:instrumentation / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000295:instrumentation / Q000379:methods*; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013997:Time Factors