Phonoangiographic Diagnosis of Stenosed Arteries: A Computational Fluid Flexible‐Structure Acoustic Interaction Study

The present article is on pulsatile hemodynamics‐induced sound‐based diagnosis of stenosis in compliant arteries of three types: Coronary, carotid, and femoral. Considering axisymmetric stenosis in straight arteries along with clinically observed dimensions of the arteries and enveloping tissue, the present numerical study considers blood as a Newtonian fluid and both artery and tissue as isotropic and geometrically nonlinear (materialistically linear) solid. For the physiological fluid flexible‐structure acoustic interaction (FfSAI) study, an in‐house multiphysics solver is used for a parametric study—using various stenosis level S$$ S $$ (60%, 70%, and 80%) and stenosis length Lst$$ {L}_{\mathrm{st}} $$ (2D and 4D); for each of the arteries. With increasing S$$ S $$ , an increase in acoustic acceleration's FFT spectrum‐based cut‐off frequency fc$$ {f}_c $$ is found—indicating possibility of quantitative phonoangiographic diagnosis. The variation of this frequency fc$$ {f}_c $$ with S$$ S $$ follows similar trend as that of frequency calculated by pressure fluctuation's FFT spectrum, thus correlating the hemodynamics as the cause for generation of the sound/bruits. Also, a flow‐visualization‐based frequency, which is calculated using vortex length and velocity during vortex dissipation stage, matches reasonably (≤ 15% difference) with the cut‐off frequency of pressure fluctuation. For the first time in the literature, our sound velocity level‐based study shows over‐prediction of stenosis by neglecting flow‐induced tissue deformations. This implies the importance of modeling structural flexibility, along with flow and acoustics while developing a computational Point‐of‐Care diagnostic tool. Finally, using analytical method for acoustics, a computationally efficient semi‐analytical FfSAI approach is proposed. The present work is significant since an accurate and computationally efficient framework and flow‐physics‐based analysis are presented for phonoangiographic diagnosis of stenosed arteries of three types.