title: Method for aortic wall strain measurement with three-dimensional ultrasound speckle tracking and fitted finite element analysis.
abstract: BACKGROUND
  Aortic wall strains are indicators of biomechanical changes of the aorta due to aging or progressing pathologies such as aortic aneurysm. We investigated the potential of time-resolved three-dimensional ultrasonography coupled with speckle-tracking algorithms and finite element analysis as a novel method for noninvasive in vivo assessment of aortic wall strain.
  
  
  METHODS
  Three-dimensional volume datasets of 6 subjects without cardiovascular risk factors and 2 abdominal aortic aneurysms were acquired with a commercial real time three-dimensional echocardiography system. Longitudinal and circumferential strains were computed offline with high spatial resolution using a customized commercial speckle-tracking software and finite element analysis. Indices for spatial heterogeneity and systolic dyssynchrony were determined for healthy abdominal aortas and abdominal aneurysms.
  
  
  RESULTS
  All examined aortic wall segments exhibited considerable heterogenous in-plane strain distributions. Higher spatial resolution of strain imaging resulted in the detection of significantly higher local peak strains (p ≤ 0.01). In comparison with healthy abdominal aortas, aneurysms showed reduced mean strains and increased spatial heterogeneity and more pronounced temporal dyssynchrony as well as delayed systole.
  
  
  CONCLUSIONS
  Three-dimensional ultrasound speckle tracking enables the analysis of spatially highly resolved strain fields of the aortic wall and offers the potential to detect local aortic wall motion deformations and abnormalities. These data allow the definition of new indices by which the different biomechanical properties of healthy aortas and aortic aneurysms can be characterized.
authors.affiliation: Department of Internal Medicine and Cardiology, Philipps University, Marburg, Marburg.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Karatolios
authors.forename: Andreas
authors.initials: A
authors.lastname: Wittek
authors.forename: Thet Htar
authors.initials: TH
authors.lastname: Nwe
authors.forename: Peter
authors.initials: P
authors.lastname: Bihari
authors.forename: Amit
authors.initials: A
authors.lastname: Shelke
authors.forename: Dennis
authors.initials: D
authors.lastname: Josef
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitz-Rixen
authors.forename: Josef
authors.initials: J
authors.lastname: Geks
authors.forename: Bernhard
authors.initials: B
authors.lastname: Maisch
authors.forename: Christopher
authors.initials: C
authors.lastname: Blase
authors.forename: Rainer
authors.initials: R
authors.lastname: Moosdorf
authors.forename: Sebastian
authors.initials: S
authors.lastname: Vogt
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging*; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D014463:Ultrasonography; D055815:Young Adult
keywords: 26; 3D; 3D-WMT; 4D; AAA; ACP; CS; CV; FE; FEA; FEM; LV; SD; SDI; US; abdominal aortic aneurysm; advanced cardiac package; circumferential strain; coefficient of variation; finite element; finite element analysis; finite element method; four-dimensional; left ventricle; standard deviation; systolic dyssynchrony index; three-dimensional; three-dimensional wall motion tracking; ultrasound