title: Vibration-synchronized magnetic resonance imaging for the detection of myocardial elasticity changes.
abstract: Vibration synchronized magnetic resonance imaging of harmonically oscillating tissue interfaces is proposed for cardiac magnetic resonance elastography. The new approach exploits cardiac triggered cine imaging synchronized with extrinsic harmonic stimulation (f = 22.83 Hz) to display oscillatory tissue deformations in magnitude images. Oscillations are analyzed by intensity threshold-based image processing to track wave amplitude variations over the cardiac cycle. In agreement to literature data, results in 10 volunteers showed that endocardial wave amplitudes during systole (0.13 ± 0.07 mm) were significantly lower than during diastole (0.34 ± 0.14 mm, P < 0.001). Wave amplitudes were found to decrease 117 ± 40 ms before myocardial contraction and to increase 75 ± 31 ms before myocardial relaxation. Vibration synchronized magnetic resonance imaging improves the temporal resolution of magnetic resonance elastography as it overcomes the use of extra motion encoding gradients, is less sensitive to susceptibility artifacts, and does not suffer from dynamic range constraints frequently encountered in phase-based magnetic resonance elastography.
authors.affiliation: Department of Radiology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Elgeti
authors.forename: Heiko
authors.initials: H
authors.lastname: Tzschätzsch
authors.forename: Sebastian
authors.initials: S
authors.lastname: Hirsch
authors.forename: Dagmar
authors.initials: D
authors.lastname: Krefting
authors.forename: Dieter
authors.initials: D
authors.lastname: Klatt
authors.forename: Thoralf
authors.initials: T
authors.lastname: Niendorf
authors.forename: Jürgen
authors.initials: J
authors.lastname: Braun
authors.forename: Ingolf
authors.initials: I
authors.lastname: Sack
mesh_terms: D000328:Adult; D016477:Artifacts; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D018709:Statistics, Nonparametric; D016277:Ventricular Function, Left / Q000502:physiology*; D014732:Vibration