Computational fluid dynamics analysis in patients with nasal disease

Computational fluid dynamics （CFD） analysis is useful for quantitative assessment in patients with upper airway obstructions. We compared CFD analysis with rhinomanometry （RM） and acoustic rhinometry （AR）. Twenty patients with nasal and paranasal diseases who required computed tomography assessment underwent RM and AR. We measured the pressure and velocity at four parts of the upper airway using CFD analysis. Then we evaluated the correlation among CFD analysis, RM, and AR. CFD analysis detected obstruction sites in the nasal airway and pharynx in 14 and 2patients, respectively. High negative pressure accompanied the nasal obstruction, even behind the nasal cavity. Nasal airway pressure measured using CFD analysis strongly correlated with nasal resistance in RM （Spearman correlation coefficient＝0.853）. CFD analysis’s sensitivity and specificity to detect the obstruction were 84.6％ and 57.1％, respectively （compared to those of RM） and 83.3％ and 50.0％, respectively （compared to those of AR）. The CFD analysis’s ability to detect obstruction was comparable to that of RM and AR; therefore, it may help evaluate the upper airways in patients with nasal and paranasal diseases. We found impaired nasal ventilation also affected other parts of the upper airway. Further studies with a larger sample size are required to validate the use of CFD analysis for assessing the degree of upper airway ventilation disorders.