title: Accuracy and repeatability of fourier velocity encoded M-mode and two-dimensional cine phase contrast for pulse wave velocity measurement in the descending aorta.
abstract: OBJECTIVE
  To assess the accuracy and repeatability of Fourier velocity encoded (FVE) M-mode and two-dimensional (2D) phase contrast with through-plane velocity encoding (2D-PC) for pulse wave velocity (PWV) evaluation in the descending aorta using five different analysis techniques.
  
  
  METHODS
  Accuracy experiments were conducted on a tubular human-tissue-mimicking phantom integrated into a flow simulator. The theoretical PWV value was derived from the Moens-Korteweg equation after measurement of the tube elastic modulus by uniaxial tensile testing (PWV = 6.6 +/- 0.7 m/s). Repeatability was assessed on 20 healthy volunteers undergoing three consecutive MR examinations.
  
  
  RESULTS
  FVE M-mode PWV was more repeatable than 2D-PC PWV independently of the analysis technique used. The early systolic fit (ESF) method, followed by the maximum of the first derivative (1st der.) method, was the most accurate (PWV = 6.8 +/- 0.4 m/s and PWV = 7.0 +/- 0.6 m/s, respectively) and repeatable (inter-scan within-subject variation delta = 0.096 and delta = 0.107, respectively) for FVE M-mode. For 2D-PC, the 1st der. method performed best in terms of accuracy (PWV = 6.8 +/- 1.1 m/s), whereas the ESF algorithm was the most repeatable (delta = 0.386).
  
  
  CONCLUSIONS
  FVE M-mode allows rapid, accurate and repeatable central PWV evaluation when the ESF algorithm is used. 2D-PC requires long scan times and can provide accurate although much less repeatable PWV measurements when the 1st der. method is used.
authors.affiliation: Department of Radiology, Cambridge University Hospitals NHS Foundation Trust, Hills Road, Cambridge, United Kingdom. vt232@cam.ac.uk
authors.forename: Valentina
authors.initials: V
authors.lastname: Taviani
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Patterson
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Graves
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hardy
authors.forename: Pauline
authors.initials: P
authors.lastname: Worters
authors.forename: Michael P F
authors.initials: MP
authors.lastname: Sutcliffe
authors.forename: Jonathan H
authors.initials: JH
authors.lastname: Gillard
mesh_terms: D000328:Adult; D001013:Aorta, Thoracic / Q000033:anatomy & histology* / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology; D003287:Contrast Media; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D011673:Pulsatile Flow / Q000502:physiology*; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media