Characterization of vascular strain during in-vitro angioplasty with high-resolution ultrasound speckle tracking

BACKGROUND: Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens. METHODS: Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data. RESULTS: Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R(2 )value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated. CONCLUSION: These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue.