Time-resolved Doppler vortography in the left ventricle

Previous studies have suggested that vortex flow in the left ventricle can be used as an indicator of the heart function. Thereby from a clinical point of view, studying the left ventricle vortex during cardiac cycles could be helpful for early diagnosis. What we propose here is the combination of a method called vortography with ultrafast Doppler echocardiography. Ultrafast ultrasound imaging is a promising field that can increase significantly the frame rate of the acquisitions. The use of ultrafast imaging can therefore provide a sufficient number of frames to describe the whole intra-cardiac blood flow during an entire cardiac cycle which cannot be achieved with conventional echography. Doppler vortography is based on recognition of the antisymmetric pattern in a vortex velocity field. The reliability of vortography has already been presented with conventional Doppler imaging. In this study we present the results from in vitro experiments on a spinning disc from which we were able to fix the angular velocity and deduce the ground truth vorticity. We observed a strong correlation between the vorticity measured with ultrafast vortography and the ground truth vorticity (r² = 0.99). We then applied the method in vivo (5 healthy volunteers) and we were able to track the main vortex in the left ventricle during the cardiac cycle.