Acoustic radiation force impulse imaging of mechanical stiffness propagation in myocardial tissue.

Published

Journal Article

Acoustic radiation force impulse (ARFI) imaging has been shown to be capable of imaging local myocardial stiffness changes throughout the cardiac cycle. Expanding on these results, the authors present experiments using cardiac ARFI imaging to visualize and quantify the propagation of mechanical stiffness during ventricular systole. In vivo ARFI images of the left ventricular free wall of two exposed canine hearts were acquired. Images were formed while the heart was externally paced by one of two electrodes positioned on the epicardial surface and either side of the imaging plane. Two-line M-mode ARFI images were acquired at a sampling frequency of 120 Hz while the heart was paced from an external stimulating electrode. Two-dimensional ARFI images were also acquired, and an average propagation velocity across the lateral field of view was calculated. Directions and speeds of myocardial stiffness propagation were measured and compared with the propagations derived from the local electrocardiogram (ECG), strain, and tissue velocity measurements estimated during systole. In all ARFI images, the direction of myocardial stiffness propagation was seen to be away from the stimulating electrode and occurred with similar velocity magnitudes in either direction. When compared with the local epicardial ECG, the mechanical stiffness waves were observed to travel in the same direction as the propagating electrical wave and with similar propagation velocities. In a comparison between ARFI, strain, and tissue velocity imaging, the three methods also yielded similar propagation velocities.

Full Text

Duke Authors

Cited Authors

  • Hsu, SJ; Byram, BC; Bouchard, RR; Dumont, DM; Wolf, PD; Trahey, GE

Published Date

  • July 2012

Published In

Volume / Issue

  • 34 / 3

Start / End Page

  • 142 - 158

PubMed ID

  • 22972912

Pubmed Central ID

  • 22972912

Electronic International Standard Serial Number (EISSN)

  • 1096-0910

International Standard Serial Number (ISSN)

  • 0161-7346

Digital Object Identifier (DOI)

  • 10.1177/0161734612456580

Language

  • eng