title: Assessment of elastase-induced murine abdominal aortic aneurysms: comparison of ultrasound imaging with in situ video microscopy.
abstract: OBJECTIVE
  The aim of this study was to definitively assess the validity of noninvasive high-frequency ultrasound (US) measurements of aortic luminal diameter (ALD) in a murine model of elastase-induced abdominal aortic aneurysm in comparison with in situ video microscopy (VM).
  
  
  METHODS
  C57BL/6 mice underwent transient perfusion of the aorta with either elastase (n = 20: Elastase group) or saline (n = 10: Sham). Unoperated mice (n = 10) were also studied.
  
  
  RESULTS
  ALD measurements by US had excellent linear correlation and absolute agreement with that by VM in both Control (unoperated or sham-operated mice) and elastase groups (r = 0.96, intraclass correlation coefficient (ICC) = 0.88 and r = 0.93, ICC = 0.92, resp.). Bland-Altman analysis of US compared with VM measurements in both groups indicated good agreement, however US measurements were slightly but significantly higher than VM measurements in the control group (mean bias 0.039 mm, P < .05). Linear regression analysis revealed excellent correlation between US and VM measurements in both groups. (R² = 0.91 in Control group, R² = 0.85 in elastase group.) The reliability of US measurements was also confirmed by ex vivo histological measurements.
  
  
  CONCLUSIONS
  High-frequency US provides reliable ALD measurements in developing murine abdominal aortic aneurysms.
authors.affiliation: Division of Cardiovascular Medicine, Stanford University School of Medicine, CA, USA.
authors.forename: Junya
authors.initials: J
authors.lastname: Azuma
authors.forename: Lars
authors.initials: L
authors.lastname: Maegdefessel
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kitagawa
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Dalman
authors.forename: Michael V
authors.initials: MV
authors.lastname: McConnell
authors.forename: Philip S
authors.initials: PS
authors.lastname: Tsao
mesh_terms: D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000139:chemically induced* / Q000000981:diagnostic imaging / Q000473:pathology*; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D016014:Linear Models; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018715:Microscopy, Video / Q000379:methods*; D010196:Pancreatic Elastase; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods*
chemical_list: D010196:Pancreatic Elastase