P1E-1 Left Ventricular Phantom with Pulsatile Circulation for Ultrasound Strain Rate Imaging

Strain rate imaging has been proposed to quantitatively evaluate myocardial deformation and potentially quantify injury of ischemic heart disease (IHD) and remodeling of myocardial infarction (MI). However, because deformation of the cardiac wall is complex and three-dimensional, it's hard to evaluate imaging algorithms (e.g., 2D/3D speckle tracking for strain rate estimation) without a well-controlled experimental system producing LV wall heart deformation patterns similar to those encountered clinically. Tissue-mimicking Polyvinyl Alcohol (PVA) cryogel LV phantoms of the left ventricle were constructed and connected to a pulsatile circulatory system for quantitative analysis of regional LV deformation using ultrasound and MR imaging. Two types were constructed: one mimicking a normal LV, and the other an otherwise normal LV but with a single hard inclusion representing a transmural infarct with higher stiffness. The hard inclusion exhibited an elastic modulus above 6 times greater than the surrounding heart wall. Both phantoms were deformed using the pulsatile pump at a stroke volume of 15ml, 20 beats per minute, and systole/diastole ratio 50:50. A specially designed commercial ultrasound scanner (iU22, Philips, Bothell, MA) was used at high frame rate. A strain estimation algorithm based on adaptive 2D speckle tracking was validated