title: In Vivo time harmonic elastography of the human heart.
abstract: Time harmonic elastography is introduced as a modality for assessing myocardial elasticity changes during the cardiac cycle. It is based on external stimulation and real-time analysis of 30-Hz harmonic shear waves in axial direction of a parasternal line of sight through the lateral heart wall. In 20 healthy volunteers, the externally induced waves showed smaller amplitudes during systole (76.0 ± 30.8 μm) and higher amplitudes during diastole (126.7 ± 52.1 μm). This periodic wave amplitude alteration preceded ventricular contraction and dilation by about 100 ms. The amplitude ratio of 1.75 ± 0.49 indicates a relative change in myocardial shear elasticity on the order of 14 ± 11. These results well agree with observations made by cardiac magnetic resonance elastography for a similar displacement component and region of the heart. The proposed method provides reproducible elastodynamic information on the heart in real-time and may help in diagnosing myocardial relaxation abnormalities in the future.
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Tzschätzsch
authors.forename: Thomas
authors.initials: T
authors.lastname: Elgeti
authors.forename: Katrin
authors.initials: K
authors.lastname: Rettig
authors.forename: Christian
authors.initials: C
authors.lastname: Kargel
authors.forename: Robert
authors.initials: R
authors.lastname: Klaua
authors.forename: Michael
authors.initials: M
authors.lastname: Schultz
authors.forename: Jürgen
authors.initials: J
authors.lastname: Braun
authors.forename: Ingolf
authors.initials: I
authors.lastname: Sack
mesh_terms: D000328:Adult; D003198:Computer Simulation; D004452:Echocardiography / Q000379:methods*; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008955:Models, Cardiovascular; D009200:Myocardial Contraction / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*