Design of carotid bifurcation phantoms for integrative imaging investigations of arterial wall and flow dynamics

Vascular phantoms are well regarded as essential experimental tools in the development of new ultrasound techniques for assessing wall mechanics and blood flow. However, existing phantoms are ill-suited for evaluation of integrative imaging methods that seek to concurrently assess biomechanics and hemodynamics. Here, we present a novel design protocol for acoustically-compatible anthropomorphic walled phantoms with artery-like vessel elasticity of carotid bifurcation with stenotic-narrowing. Our protocol involved a set of three-dimensional printed mold parts (consisted of a vessel core and an outer mold) for investment casting of polyvinyl alcohol solution to construct the elastic vessel tube. Agar-gelatin slab was formed around the vessel tube mimicking surrounding tissue. For demonstration, a set of healthy and stenosed (25%, 50%, and 75%) carotid bifurcation phantoms were developed. Imaging experiments were performed on these phantoms to visualize complex blood flow (recirculation and flow jet formation observed) and pulse wave dynamics (derived pulse wave velocity = 4.67 ± 0.71 m/s). Integrative imaging of wall motion and blood flow in our phantoms also revealed fluid-structure interaction differences between healthy and diseased models. These findings show that phantoms developed with our new protocol are useful in vascular imaging studies that individually or jointly assess wall motion and flow dynamics. Vascular phantoms are well regarded as essential experimental tools in the development of new ultrasound techniques for assessing wall mechanics and blood flow. However, existing phantoms are ill-suited for evaluation of integrative imaging methods that seek to concurrently assess biomechanics and hemodynamics. Here, we present a novel design protocol for acoustically-compatible anthropomorphic walled phantoms with artery-like vessel elasticity of carotid bifurcation with stenotic-narrowing. Our protocol involved a set of three-dimensional printed mold parts (consisted of a vessel core and an outer mold) for investment casting of polyvinyl alcohol solution to construct the elastic vessel tube. Agar-gelatin slab was formed around the vessel tube mimicking surrounding tissue. For demonstration, a set of healthy and stenosed (25%, 50%, and 75%) carotid bifurcation phantoms were developed. Imaging experiments were performed on these phantoms to visualize complex blood flow (recirculation and flow jet formati...