Vortex Ring Phantom for Investigation of Ultrasound Vector Flow Imaging

High frame rate ultrasound allows accurate quantification of the velocity flows, which could improve the current measurements that assist clinicians in diagnosis. The validation of novel approaches is essential before considering their translation to clinical ultrasound. To achieve this, we propose to use a vortex ring phantom, which presents two advantages. First, it offers complex three-dimensional flow patterns that closely reproduces intracardiac flow jets. Second, it is supposed to be controllable, reproducible and transportable, which is of key importance when validating new techniques. In this context, our objective was to evaluate if such a vortex phantom is a good candidate for validating and optimizing high-frame-rate velocity estimation methods. The 2D vortex kinematics was successfully recovered using speckle tracking and Doppler estimates. A good correlation (r2 = 0.95) was found between the rotational and the translational velocity components for 315 estimations. Our preliminary 3-D results showed that Doppler velocities can be estimated in both sagittal and axial planes at thousands of volumes per second. In conclusion, the vortex phantom can be considered as a good candidate for testing novel high-frame-rate velocity estimation approaches.