Author:

Keywords:

Tendon mechanics, Ultrasound elastography, Science & Technology, Life Sciences & Biomedicine, Technology, Biophysics, Engineering, Biomedical, Engineering, REAL-TIME SONOELASTOGRAPHY, SPECKLE TRACKING, ACHILLES-TENDON, MECHANICAL-PROPERTIES, DISPLACEMENT, APONEUROSIS, ELASTICITY, PATTERNS, Animals, Elasticity Imaging Techniques, Humans, Models, Biological, Motion, Phantoms, Imaging, Stress, Mechanical, Swine, Tendon Injuries, Tendons, Transducers, Weight-Bearing, 0903 Biomedical Engineering, 0913 Mechanical Engineering, 1106 Human Movement and Sports Sciences, Biomedical Engineering, 4003 Biomedical engineering, 4207 Sports science and exercise

Abstract:

The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R(2)>0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5±0.2%; RF: 3.7±0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R(2)>0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6±1.4%; RF: 2.2±1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states.