Ultrasonic strain measurements of tendon

Elasticity imaging has gained wide interest in medical ultrasound. In rehabilitative medicine, such a tool may be of great clinical importance since it is capable of directly assessing the mechanical properties of tendon. A critical component in elasticity imaging is estimation of the strain fields. In this study, axial strain fields of rabbit Achilles tendons were measured in vitro. Strain measurements were also correlated with conventional B-mode sonograms and histological micrographs. Results indicated that the strain measurements had reasonable agreement with histological examinations and provided better tissue differentiation than conventional B-mode imaging. For a given tendon, the strain values corresponding to different tissue layers were easily differentiated. Such differences, however, were not always present in the sonograms. An elasticity reconstruction approach based on axial strain measurements was also briefly discussed