Doppler vortography - Detection and quantification of the vortices in the left ventricle

It has been speculated that the natural swirling flow that occurs in the normal left ventricle (LV) during LV filling is optimized in terms of fluid energy dissipation. In vivo findings also revealed the formation of additional counter-rotating vortices in the presence of cardiac disease. Such unnatural vortices may significantly impair the LV function due to important kinetic dissipation. We propose a new method for quantification of intracardiac vorticity - Doppler vortography - based on conventional Doppler images only. Doppler vortography relies on the centrosymmetric properties of the vortices. Such properties induce particular symmetries in the Doppler flow data which can be exploited to describe the vortices quantitatively. For this purpose, a kernel filter was developed to derive a parameter, the blood vortex signature (BVS), that allows detecting the main intracardiac vortices and estimating their core vorticities. The reliability of BVS measured by Doppler vortography was assessed in mock Doppler vortical fields and compared with the ground-truth vorticity mapping. Doppler vortography was also tested in healthy subjects and patients. The simulation and in vitro results demonstrated that Doppler vortography is a highly reliable technique for the detection and quantification of the intraventricular vortices. The diastolic BVS measured in the echographic laboratory, at the end of the LV early filling, revealed the presence of retrograde vortices in patients with cardiac disease. Doppler vortography is a promising echocardiographic tool for quantification of vortex flow in the left ventricle. Our findings suggest that Doppler vortography potentially has relevant clinical interest for the assessment of LV diastolic function.