title: Non-triggered quantification of central and peripheral pulse-wave velocity.
abstract: OBJECTIVE
  Stiffening of the arteries results in increased pulse-wave velocity (PWV), the propagation velocity of the blood. Elevated aortic PWV has been shown to correlate with aging and atherosclerotic alterations. We extended a previous non-triggered projection-based cardiovascular MR method and demonstrate its feasibility by mapping the PWV of the aortic arch, thoraco-abdominal aorta and iliofemoral arteries in a cohort of healthy adults.
  
  
  METHODS
  The proposed method "simultaneously" excites and collects a series of velocity-encoded projections at two arterial segments to estimate the wave-front velocity, which inherently probes the high-frequency component of the dynamic vessel wall modulus in response to oscillatory pressure waves. The regional PWVs were quantified in a small pilot study in healthy subjects (N = 10, age range 23 to 68 yrs) at 3T.
  
  
  RESULTS
  The projection-based method successfully time-resolved regional PWVs for 8-10 cardiac cycles without gating and demonstrated the feasibility of monitoring beat-to-beat changes in PWV resulting from heart rate irregularities. For dual-slice excitation the aliasing was negligible and did not interfere with PWV quantification. The aortic arch and thoracoabdominal aorta PWV were positively correlated with age (p < 0.05), consistent with previous reports. On the other hand, the PWV of the iliofemoral arteries showed decreasing trend with age, which has been associated with the weakening of muscular arteries, a natural aging process.
  
  
  CONCLUSIONS
  The PWV map of the arterial tree from ascending aorta to femoral arteries may provide additional insight into pathophysiology of vascular aging and atherosclerosis.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Langham
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.forename: Felix W
authors.initials: FW
authors.lastname: Wehrli
mesh_terms: D000328:Adult; D000368:Aged; D001012:Aorta, Abdominal / Q000502:physiology; D001013:Aorta, Thoracic / Q000502:physiology; D001158:Arteries / Q000502:physiology*; D001794:Blood Pressure; D005240:Feasibility Studies; D005263:Femoral Artery / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D007083:Iliac Artery / Q000502:physiology; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015143:Philadelphia; D010865:Pilot Projects; D011673:Pulsatile Flow; D012016:Reference Values; D012039:Regional Blood Flow; D013997:Time Factors; D055815:Young Adult