Image-based speckle tracking for tissue motion characterization in a deformable cardiovascular phantom

We present and validate image-based speckle-tracking calipers for quantification of tissue deformation and rotation in dynamic cardiovascular phantom models. Lagrangian strain was computed from the change in distance between caliper regions-of-interest (ROIs) positioned within the wall of a pulsatile phantom and compared with reference measurements derived from cardiac CT imaging. In a torsion phantom, rotational tissue excursion in a 2D plane was estimated and compared with reference values from CT-scan data. Tissue deformation and rotation measurements correlated well with their respective reference measurements. Our algorithm is capable of estimating strain and rotation from distinct tissue regions without requiring explicit cardiac border detection, a step which can be especially challenging in patients with poor acoustic windows.