A complex flow phantom for medical imaging: ring vortex phantom design and technical specification

Abstract

Cardiovascular fluid dynamics exhibit complex flow patterns, such as recirculation and vortices. Quantitative analysis of these complexities supports diagnosis, leading to early prediction of pathologies. Quality assurance of technologies that image such flows is challenging but essential, and to this end, a novel, cost-effective, portable, complex flow phantom is proposed and the design specifications are provided. The vortex ring is the flow of choice because it offers patterns comparable to physiological flows and is stable, predictable, reproducible and controllable. This design employs a piston/cylinder system for vortex ring generation, coupled to an imaging tank full of fluid, for vortex propagation. The phantom is motor-driven and by varying piston speed, piston displacement and orifice size, vortex rings with different characteristics can be produced. Two measurement methods, namely Laser-PIV and an optical/video technique, were used to test the phantom under a combination of configurations. Vortex rings with a range of travelling velocities (approximately 1–80 cm/s) and different output-orifice diameters (10–25 mm) were produced with reproducibility typically better than ±10%. Although ultrasound compatibility has been demonstrated, longer-term ambitions include adapting the design to support comparative studies with different modalities, such as MRA and X-ray-CTA.

Keywords:

• Medical imaging phantom
• Doppler ultrasound quality assurance
• vortex ring
• complex flow phantom
• laser PIV

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is funded by the European Commission through the H2020 Marie Sklodowska-Curie European VPH-CaSE Training Network (www.vph-case.eu), GA No. 642612. The vortex ring-based flow phantom has been manufactured using the facilities of Leeds Test Objects Ltd (Leeds Test Objects Ltd, Boroughbridge, UK), as beneficiary and partner of the VPH-CaSE consortium (http://www.vph-case.eu/, EU Horizon 2020 funding Marie Curie Training Network).