Development of a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms.

Polyvinyl alcohol cryogel (PVA-C) is presented as a vessel-mimicking material for use in anatomically realistic Doppler flow phantoms. Three different batches of 10% wt PVA-C containing (i) PVA-C alone, (ii) PVA-C with antibacterial agent and (iii) PVA-C with silicon carbide particles were produced, each with 1-6 freeze-thaw cycles. The resulting PVA-C samples were characterized acoustically (over a range 2.65 to 10.5 MHz) and mechanically to determine the optimum mixture and preparation for mimicking the properties of healthy and diseased arteries found in vivo. This optimum mix was reached with the PVA-C with antibacterial agent sample, prepared after two freeze/thaw cycles, which achieved a speed of sound of 1538 ± 5 m s(-1) and a Young's elastic modulus of 79 ± 11 kPa. This material was used to make a range of anatomically realistic flow phantoms with varying degrees of stenoses, and subsequent flow experiments revealed that higher degrees of stenoses and higher velocities could be achieved without phantom rupturing compared with a phantom containing conventional wall-less vessels.