title: Three-dimensional speckle-tracking imaging for left ventricular rotation measurement: an in vitro validation study.
abstract: OBJECTIVE
  Left ventricular (LV) twist is manifested in oppositely directed apical and basal rotation. We studied a new 3-dimensional (3D) echocardiography program (wall motion tracking; Toshiba America Medical Systems, Inc, Tustin, CA) for left ventricular rotation.
  
  
  METHODS
  We used a rotation model with a variable-speed motor to rotate hearts in a water bath. We studied 10 freshly harvested pig hearts, which were mounted on the rotary actuator of our twist phantom with the heart base rotating and the apex held fixed to avoid translational motion, at rotations of 0 degrees , 15 degrees , 20 degrees , and 25 degrees . Full-volume 3D image loops were acquired on a Toshiba Aplio Artida ultrasound system at a maximized frame rate.
  
  
  RESULTS
  As the actual heart rotation increased, computed segmental and global rotation also increased accordingly, with the measured rotations of the basal and middle segments greater than that of the apex (both P < .001). Segmental and global rotation at all 3 levels correlated well with the actual rotation (base: r = 0.93; middle: r = 0.92; apex: r = 0.82; global: r = 0.95; all P < .001).
  
  
  CONCLUSIONS
  The new 3D program tracked LV rotation accurately.
authors.affiliation: Shanghai 10th People's Hospital, affiliated with Tongji University, Shanghai, China.
authors.forename: Zhiwen
authors.initials: Z
authors.lastname: Zhou
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ashraf
authors.forename: Dayi
authors.initials: D
authors.lastname: Hu
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Dai
authors.forename: Yawei
authors.initials: Y
authors.lastname: Xu
authors.forename: Bill
authors.initials: B
authors.lastname: Kenny
authors.forename: Berkley
authors.initials: B
authors.lastname: Cameron
authors.forename: Thuan
authors.initials: T
authors.lastname: Nguyen
authors.forename: Li
authors.initials: L
authors.lastname: Xiong
authors.forename: David J
authors.initials: DJ
authors.lastname: Sahn
mesh_terms: D000818:Animals; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D066298:In Vitro Techniques; D016014:Linear Models; D015203:Reproducibility of Results; D012399:Rotation; D013552:Swine