title: Ultra-high frame rate tissue Doppler imaging.
abstract: We describe a new tissue Doppler imaging (TDI) method, ultra-high frame rate tissue Doppler imaging (UFR-TDI). With two broad transmit beams covering only the ventricular walls, we achieve 1200 frames/s in a four-chamber apical view. We examined 10 healthy volunteers to study the feasibility of this method. Ultra-high-frame-rate TDI provided peak annular velocities and time to peak S' intervals in good agreement with those measured with conventional TDI. Moreover, UFR-TDI provided additional information in early and late systole: In all subjects, the method was able to separate the timing of electrical activation, start of mechanical contraction, mitral valve closure and start of ejection. The earliest mechanical activation was seen before mitral valve closure. The method was also able to measure the propagation speed of the mechanical wave created by aortic valve closure.
authors.affiliation: MI Lab and Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: birger.brekke@ntnu.no.
authors.forename: Birger
authors.initials: B
authors.lastname: Brekke
authors.forename: Lars C L
authors.initials: LC
authors.lastname: Nilsen
authors.forename: Joakim
authors.initials: J
authors.lastname: Lund
authors.forename: Hans
authors.initials: H
authors.lastname: Torp
authors.forename: Tore
authors.initials: T
authors.lastname: Bjastad
authors.forename: Brage H
authors.initials: BH
authors.lastname: Amundsen
authors.forename: Asbjorn
authors.initials: A
authors.lastname: Stoylen
authors.forename: Svein A
authors.initials: SA
authors.lastname: Aase
mesh_terms: D000465:Algorithms; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014741:Video Recording / Q000379:methods*
keywords: Aortic valve closure; Continuous acquisition; Echocardiography; Mechanical wave propagation; Multi-line acquisition; Myocardium function; Plane wave imaging; Pre-ejection period