title: Agreement between methods of measurement of mean aortic wall thickness by MRI.
abstract: OBJECTIVE
  To assess the agreement between three methods of calculation of mean aortic wall thickness (MAWT) using magnetic resonance imaging (MRI).
  
  
  METHODS
  High-resolution MRI of the infrarenal abdominal aorta was performed on 70 subjects with a history of coronary artery disease who were part of a multi-ethnic population-based sample. MAWT was calculated as the mean distance between the adventitial and luminal aortic boundaries using three different methods: average distance at four standard positions (AWT-4P), average distance at 100 automated positions (AWT-100P), and using a mathematical computation derived from the total vessel and luminal areas (AWT-VA). Bland-Altman plots and Passing-Bablok regression analyses were used to assess agreement between methods.
  
  
  RESULTS
  Bland-Altman analyses demonstrated a positive bias of 3.02+/-7.31% between the AWT-VA and the AWT-4P methods, and of 1.76+/-6.82% between the AWT-100P and the AWT-4P methods. Passing-Bablok regression analyses demonstrated constant bias between the AWT-4P method and the other two methods. Proportional bias was, however, not evident among the three methods.
  
  
  CONCLUSIONS
  MRI methods of measurement of MAWT using a limited number of positions of the aortic wall systematically underestimate the MAWT value compared with the method that calculates MAWT from the vessel areas.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, Dallas Texas 75390-9157, USA. eric.rosero@utsouthwestern.edu
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rosero
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Peshock
authors.forename: Amit
authors.initials: A
authors.lastname: Khera
authors.forename: G Patrick
authors.initials: GP
authors.lastname: Clagett
authors.forename: Hao
authors.initials: H
authors.lastname: Lo
authors.forename: Carlos
authors.initials: C
authors.lastname: Timaran
mesh_terms: D001012:Aorta, Abdominal / Q000473:pathology*; D001837:Body Weights and Measures / Q000379:methods; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000175:diagnosis*; D004730:Endothelium, Vascular / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D013781:Texas