Investigation of the effects of nasal surgery on nasal cavity flow using magnetic resonance velocimetry and computational fluid dynamics

The nasal cavity has the function of conditioning the air inhaled into the lungs by heating, humidifying, and filtering dust and virus-borne aerosols. Analyzing the flow field in the nasal cavity is vital because its function is strongly related to flow dynamics. Due to experimental limitations posed by the complex internal geometry of the nasal cavity, most previous studies have utilized Reynolds averaged Navier–Stokes based computational fluid dynamics (CFD) simulations. In this study, the flow field in a post-operative nasal cavity was evaluated using not only CFD simulations but also four-dimensional magnetic resonance velocimetry. The study was conducted under resting breathing conditions in pre- and post-operative models of a patient who received septoplasty and turbinoplasty. The experimental results confirmed balanced flow rates in the left and right nasal cavities after septoplasty and a decrease in velocity after turbinoplasty with a reduction in regions with vortices and reverse flow. Upon comparison, CFD results using the laminar, k–ω, and shear stress transport models were deemed to be consistent with the experimental results. However, there was a relatively large deviation observed with the k–ε model. Using the validated laminar CFD model, it was shown that the pressure and wall shear stress decreased after surgery.