Giancarlo B Cherobin1, Richard L Voegels1, Fábio R Pinna1, Eloisa M M S Gebrim2, Ryan S Bailey3,4, Guilherme J M Garcia3,4. 1. Department of Ophtalmology and Otorhinolaryngology, Universidade de São Paulo, São Paulo, Brazil. 2. Department of Radiology, Radiology Institute (InRad), Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil. 3. Department of Biomedical Engineering, Marquette University and The Medical College of Wisconsin, Milwaukee, Wisconsin. 4. Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin.
Abstract
BACKGROUND: Past studies reported a low correlation between rhinomanometry and computational fluid dynamics (CFD), but the source of the discrepancy was unclear. Low correlation or lack of correlation has also been reported between subjective and objective measures of nasal patency. OBJECTIVE: This study investigates (1) the correlation and agreement between nasal resistance derived from CFD (RCFD) and rhinomanometry (RRMN), and (2) the correlation between objective and subjective measures of nasal patency. METHODS: Twenty-five patients with nasal obstruction underwent anterior rhinomanometry before and after mucosal decongestion with oxymetazoline. Subjective nasal patency was assessed with a 0-10 visual analog scale (VAS). CFD simulations were performed based on computed tomography scans obtained after mucosal decongestion. To validate the CFD methods, nasal resistance was measured in vitro (REXPERIMENT) by performing pressure-flow experiments in anatomically accurate plastic nasal replicas from 6 individuals. RESULTS: Mucosal decongestion was associated with a reduction in bilateral nasal resistance (0.34 ± 0.23 Pa.s/ml to 0.19 ± 0.24 Pa.s/ml, p = 0.003) and improved sensation of nasal airflow (bilateral VAS decreased from 5.2 ± 1.9 to 2.6 ± 1.9, p < 0.001). A statistically significant correlation was found between VAS in the most obstructed cavity and unilateral airflow before and after mucosal decongestion (r = -0.42, p = 0.003). Excellent correlation was found between RCFD and REXPERIMENT (r = 0.96, p < 0.001) with good agreement between the numerical and in vitro values (RCFD/REXPERIMENT = 0.93 ± 0.08). A weak correlation was found between RCFD and RRMN (r = 0.41, p = 0.003) with CFD underpredicting nasal resistance derived from rhinomanometry (RCFD/RRMN = 0.65 ± 0.63). A stronger correlation was found when unilateral airflow at a pressure drop of 75 Pa was used to compare CFD with rhinomanometry (r = 0.76, p < 0.001). CONCLUSION: CFD and rhinomanometry are moderately correlated, but CFD underpredicts nasal resistance measured in vivo due in part to the assumption of rigid nasal walls. Our results confirm previous reports that subjective nasal patency correlates better with unilateral than with bilateral measurements and in the context of an intervention.
BACKGROUND: Past studies reported a low correlation between rhinomanometry and computational fluid dynamics (CFD), but the source of the discrepancy was unclear. Low correlation or lack of correlation has also been reported between subjective and objective measures of nasal patency. OBJECTIVE: This study investigates (1) the correlation and agreement between nasal resistance derived from CFD (RCFD) and rhinomanometry (RRMN), and (2) the correlation between objective and subjective measures of nasal patency. METHODS: Twenty-five patients with nasal obstruction underwent anterior rhinomanometry before and after mucosal decongestion with oxymetazoline. Subjective nasal patency was assessed with a 0-10 visual analog scale (VAS). CFD simulations were performed based on computed tomography scans obtained after mucosal decongestion. To validate the CFD methods, nasal resistance was measured in vitro (REXPERIMENT) by performing pressure-flow experiments in anatomically accurate plastic nasal replicas from 6 individuals. RESULTS: Mucosal decongestion was associated with a reduction in bilateral nasal resistance (0.34 ± 0.23 Pa.s/ml to 0.19 ± 0.24 Pa.s/ml, p = 0.003) and improved sensation of nasal airflow (bilateral VAS decreased from 5.2 ± 1.9 to 2.6 ± 1.9, p < 0.001). A statistically significant correlation was found between VAS in the most obstructed cavity and unilateral airflow before and after mucosal decongestion (r = -0.42, p = 0.003). Excellent correlation was found between RCFD and REXPERIMENT (r = 0.96, p < 0.001) with good agreement between the numerical and in vitro values (RCFD/REXPERIMENT = 0.93 ± 0.08). A weak correlation was found between RCFD and RRMN (r = 0.41, p = 0.003) with CFD underpredicting nasal resistance derived from rhinomanometry (RCFD/RRMN = 0.65 ± 0.63). A stronger correlation was found when unilateral airflow at a pressure drop of 75 Pa was used to compare CFD with rhinomanometry (r = 0.76, p < 0.001). CONCLUSION: CFD and rhinomanometry are moderately correlated, but CFD underpredicts nasal resistance measured in vivo due in part to the assumption of rigid nasal walls. Our results confirm previous reports that subjective nasal patency correlates better with unilateral than with bilateral measurements and in the context of an intervention.
Entities:
Keywords:
anterior rhinomanometry; computational fluid dynamics; correlation; experimental validation or in vitro experiments; in vivo measurements; nasal airway obstruction; nasal resistance and nasal airflow; nose and vas scores; numerical simulations; subjective nasal patency
Authors: Nora Schmidt; Hans Behrbohm; Leonid Goubergrits; Thomas Hildebrandt; Jan Brüning Journal: Int J Comput Assist Radiol Surg Date: 2022-07-11 Impact factor: 3.421
Authors: Qiwei Xiao; Neil J Stewart; Matthew M Willmering; Chamindu C Gunatilaka; Robert P Thomen; Andreas Schuh; Guruprasad Krishnamoorthy; Hui Wang; Raouf S Amin; Charles L Dumoulin; Jason C Woods; Alister J Bates Journal: PLoS One Date: 2021-08-19 Impact factor: 3.752
Authors: Manuel Berger; Aris I Giotakis; Martin Pillei; Andreas Mehrle; Michael Kraxner; Florian Kral; Wolfgang Recheis; Herbert Riechelmann; Wolfgang Freysinger Journal: Int J Comput Assist Radiol Surg Date: 2021-03-07 Impact factor: 2.924
Authors: Oleg G Avrunin; Yana V Nosova; Ibrahim Younouss Abdelhamid; Sergii V Pavlov; Natalia O Shushliapina; Natalia A Bouhlal; Ainur Ormanbekova; Aigul Iskakova; Damian Harasim Journal: Sensors (Basel) Date: 2021-12-20 Impact factor: 3.576