Applications of Acoustic Rhinometry in the Modeling of Living Human Nasal Cavity Based on CT Scan

Author(s):  
Yingxi Liu ◽  
Jun Zhang ◽  
Xiuzhen Sun

Acoustic rhinometry can quantify upper airway condition of air draft by drawing a graph plotting the distance from the nostril vs. the cross-sectional area. Some decrease on the graph corresponds to the typical anatomic structures of human nasal cavity. The 3-dimensional, computing fluid dynamic model of the same person was developed based on computed tomography scans. The veracity of the CFD model were valued by contrasting the relevant areas of stenosis site between the model and the AR graph. The aim in this study is to make clear how to use an AR to help improve and enrich the CFD model with the information of graph acquired from the measurement. The combination of AR and CT can be used to establish a living human nasal cavity model with higher significant information content.

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Chih Fang Lee ◽  
Mohd. Zulkifly Abdullah ◽  
Kamarul Arifin Ahmad ◽  
Ibrahim Lutfi Shuaib

This research focuses on creating a standardized nasal cavity model of adult Malaysian females. The methodology implemented in this research is a new approach compared to other methods used by previous researchers. This study involves 26 females who represent the test subjects for this preliminary study. Computational fluid dynamic (CFD) analysis was carried out to better understand the characteristics of the standardized model and to compare it to the available standardized Caucasian model. This comparison includes cross-sectional areas for both half-models as well as velocity contours along the nasal cavities. The Malaysian female standardized model is larger in cross-sectional area compared to the standardized Caucasian model thus leading to lower average velocity magnitudes. The standardized model was further evaluated with four more Malaysian female test subjects based on its cross-sectional areas and average velocity magnitudes along the nasal cavities. This evaluation shows that the generated model represents an averaged and standardized model of adult Malaysian females.


1997 ◽  
Vol 117 (4) ◽  
pp. 349-354 ◽  
Author(s):  
Jacquelynne P. Corey ◽  
Anil Gungor ◽  
Robert Nelson ◽  
Jeff Fredberg ◽  
Vincent Lai

Acoustic rhinometry (AR) evaluates the geometry of the nasal cavity with acoustic reflections and provides information about nasal cross-sectional areas (CSA) and nasal volume within a given distance. The accuracy of the information obtained by AR was compared with that of magnetic resonance imaging (MRI) of the nasal cavity. Five healthy subjects were evaluated with AR and the MRI before and after the application of a long-acting nasal decongestant spray, to eliminate possible interference of the nasal cycle with both measurement techniques. The MRI images of 2 mm coronal sections of the nasal cavity were traced by three independent observers and the CSAs were calculated by computer-aided imaging digitization, to be compared with the calculated CSAs obtained with the AR at the corresponding distance from the nasal tip. Digitized data from the MRI images were also used to calculate the nasal volume within the first 6 cm from the nasal tip and compared with the AR volume measurements. The interobserver variation of digitized MRI data predecongestant and postdecongestant was not significant. The correlations of CSA and volume measurements between the AR and MRI were high (0.969) after the application of the decongestant. The correlation between the AR and MRI measurements before the decongestant was low (0.345). This may have been the result of interference of the nasal cycle during the long MRI measurements (1 hour) or other unknown factors. We conclude that AR measurements of nasal CSAs and volumes provide accurate information when compared with the MRI of the decongested nasal airway.


1997 ◽  
Vol 11 (5) ◽  
pp. 399-402 ◽  
Author(s):  
Jan Gosepath ◽  
Wolf J. Mann ◽  
Ronald G. Amedee

The Breathe Right nasal strips are more and more commonly used, mainly by athletes, who hope to enhance their physical performance in competition and training. The effect of the device in such situations is uncertain and perhaps somewhat controversial. To investigate the effects of the nasal strips on nasal ventilation, 20 Caucasian individuals were objectively assessed using anterior rhinomanometry and acoustic rhinometry. The results showed a significant increase in all subjects of transnasal airflow and in the average cross-sectional area of the nasal cavity that quantifies objectively the subjective impression of improved nasal breathing. In such patients where an improvement in nasal ventilation is desired, the use of the Breathe Right nasal strips seems to offer a beneficial treatment.


2012 ◽  
Vol 17 (4) ◽  
pp. 129-133 ◽  
Author(s):  
Carla Enoki Itikawa ◽  
Fabiana Cardoso Pereira Valera ◽  
Mírian Aiko Nakane Matsumoto ◽  
Wilma Terezinha Anselmo Lima

OBJECTIVE: To assess the effects of rapid maxillary expansion on facial morphology and on nasal cavity dimensions of mouth breathing children by acoustic rhinometry and computed rhinomanometry. METHODS: Cohort; 29 mouth breathing children with posterior crossbite were evaluated. Orthodontic and otorhinolaryngologic documentation were performed at three different times, i.e., before expansion, immediately after and 90 days following expansion. RESULTS: The expansion was accompanied by an increase of the maxillary and nasal bone transversal width. However, there were no significant differences in relation to mucosal area of the nose. Acoustic rhinometry showed no difference in the minimal cross-sectional area at the level of the valve and inferior turbinate between the periods analyzed, although rhinomanometry showed a statistically significant reduction in nasal resistance right after expansion, but were similar to pre-treatment values 90 days after expansion. CONCLUSION: The maxillary expansion increased the maxilla and nasal bony area, but was inefficient to increase the nasal mucosal area, and may lessen the nasal resistance, although there was no difference in nasal geometry. Significance: Nasal bony expansion is followed by a mucosal compensation.


1996 ◽  
Vol 10 (6) ◽  
pp. 393-398 ◽  
Author(s):  
Maija L Hytönen ◽  
Eeva L Sala ◽  
Henrik O Malmberg ◽  
Henrik Nordman

Acoustic rhinometry (ARM) has been used to study the nasal cavity geometry and the response in nasal provocations. However, the use of ARM in the diagnosis of occupational rhinitis (OR) has not been reported. The purpose of this study was to find an ARM parameter and a limit value that could be used in provocation tests to express an objective change in the nasal cavity geometry. We used a new calculated parameter, Volume MCA%, for describing the change in the nasal geometry. Volume MCA% is the mean of the percentile changes of nasal volumes and minimal cross-sectional areas in a provocation test. We recommend a decrease of at least 15% in Volume MCA% for the limit of an essential change in the nasal cavity.


1991 ◽  
Vol 105 (3) ◽  
pp. 178-180 ◽  
Author(s):  
O. Elbrønd ◽  
J. U. Feeding ◽  
K. M. Gustavsen

AbstractAcoustic rhinometry is a new method which describes the geometry of the nasal cavity and the epipharynx. The method, based on the reflection of an acoustic signal entered into the nasal cavity, can be used to evaluate the cross-sectional area of the nasal cavity asa function of distance from the nostril. The method has, together with nasal expiratory peak flow (NPF) and nasal index based upon a self assessment score, been used to evaluate, in an objective and dynamic way, the effect of systemic treatment of nasal polyps with steroids in a series of eight patients with recurrent nasal polyposis. The study shows a significant relationship between these three parameters before and after systemic treatment of nasal polyps with steroids. It is concluded that in this study acoustic rhinometry had an accurate and objective method for measuring the geometry of the nasal cavity before and after treatment for processes which block the nasal cavity.


2019 ◽  
Vol 129 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Hanyao Huang ◽  
Heng Yin ◽  
Yang Wang ◽  
Nan Chen ◽  
Dantong Huang ◽  
...  

Objective: Velopharyngeal (VP) closure has high impact on the quality of life, especially in patients with cleft palate. For better understanding the VP closure, it is important to understand the airflow dynamics of different closure patterns, including circular, coronal, sagittal, and circular with a Passavant’s ridge. The purpose of this study was to demonstrate the airflow characteristics of different velopharyngeal closure patterns. Methods: Sixteen adults with no notable upper airway abnormality who needed multislice spiral computed tomography scans as part of their clinical care. Airways were reconstructed. A cylinder and a cuboid were used to replace the VP port in three models of VP port patterns. Flow simulations were carried using computational fluid dynamics. Airflow pressures in the VP orifice, oral cavity and nasal cavity, as well as airflow velocity through the velopharyngeal orifice, were calculated. Results: The airflow dynamics at the velopharynx were different among different velopharyngeal patterns as the area of the velopharyngeal port increased from 0 to 25 mm2. The orifice areas of different closure conditions in four velopharyngeal closure patterns were significantly different. The maximal orifice area for adequate velopharyngeal closure was 7.57 mm2 in the coronal pattern and 6.21 mm2 in the sagittal pattern. Conclusions: Airflow dynamics of the velopharynx were correlated to the velopharyngeal closure patterns. Different closure patterns had different largest permitted orifice areas for getting the appropriate oral pressures for normal speech.


2000 ◽  
Vol 89 (3) ◽  
pp. 1013-1021 ◽  
Author(s):  
Hendrik Terheyden ◽  
Steffen Maune ◽  
Jürgen Mertens ◽  
Ole Hilberg

The aim of the present study was a validation of acoustic rhinometry (AR) by computed tomography (CT). Six healthy subjects were examined by CT and AR. The CT data were processed in a computer program (AutoCAD), and a virtual three-dimensional model of each nasal cavity was constructed. This model permitted an individual prediction of the center line of the sound wave propagation through the air volume of the nasal cavity with the cross-sectional areas oriented perpendicularly to this line. The area-distance curves derived from AR and CT were compared. Linear regression analysis revealed a reasonable agreement of AR and CT in the anterior nose below a mean of 6 cm distance from the nostrils [ r = 0.839, P < 0.01, m = 1.123, b= −0.113 (AR = m × CT + b)]. The measuring accuracy using CT as gold standard revealed a mean error at the nasal valve of <0.01 cm2 (4.52%) and at the nasal isthmus of 0.02 cm2 (1.87%). Beyond 6 cm, the correlation decreased ( r = 0.419), and overestimation of the true area occurred (>100%). In conclusion, the measurements were reasonably accurate for diagnostic use up to the turbinate head region. Certain factors induce an overestimation of the true areas beyond this region. However, these factors are constant and reproducible in a single subject, and intraindividual comparative measurements are possible beyond the turbinate head region.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 662
Author(s):  
Johannes Sebastian Siedenburg ◽  
Gilles Dupré

Relative macroglossia has been identified in brachycephalic compared to mesaticephalic dogs. This study assessed the tongue volume comparing three common brachycephalic breeds, including 30 French bulldogs, 30 pugs, and 15 English bulldogs. Computed tomography scans of intubated dogs with the hard palate suspended were examined for total tongue volume and cross-sectional areas (CSAs) of the tongue, oropharynx, soft palate, and nasopharyngeal airways at three levels: 1, caudal tip of the hard palate; 2, caudal tip of the hamulus; 3 cranial to the basihyoid bone. Tongue volume normalized to bodyweight, was significantly higher in English and French bulldogs than in pugs. Normalized to skull length, CSA of the tongue was smaller in pugs than in French and English bulldogs. At level 3, French bulldogs had larger oropharyngeal CSA than English bulldogs and pugs. Soft palate CSA was the largest in English bulldogs at level 3. At levels 1 and 2, soft palate and nasopharyngeal CSA was the smallest in pugs. At level 3, French bulldogs had higher total airway/soft tissue ratios than pugs. The smaller tongue volume in pugs questions the accuracy of the term macroglossia in this breed and these findings should be considered if surgical correction is sought.


2005 ◽  
Vol 99 (2) ◽  
pp. 616-623 ◽  
Author(s):  
Erkan Tarhan ◽  
Mehmet Coskun ◽  
Ozcan Cakmak ◽  
Hüseyin Çelik ◽  
Mehmet Cankurtaran

A comprehensive study that compared acoustic rhinometry (AR) data to computed tomography (CT) data was performed to evaluate the accuracy of AR measurements in estimating nasal passage area and to assess its ability of quantifying paranasal sinus volume and ostium size in live humans. Twenty nasal passages of 10 healthy adults were examined by using AR and CT. Actual cross-sectional areas of the nasal cavity, sinus ostia sizes, and maxillary and frontal sinus volumes were determined from CT sections perpendicular to the curved acoustic axis of the nasal passage. Nasal cavity volume (from nostril to choana) calculated from the AR-derived area-distance curve was compared with that from the CT-derived area-distance curve. AR measurements were also done on pipe models that featured a side branch (Helmholtz resonator of constant volume but two different neck diameters) simulating a paranasal sinus. In the anterior nasal cavity, there was good agreement between the cross-sectional areas determined by AR and CT. However, posterior to the sinus ostia, AR overestimated cross-sectional area. The difference between AR nasal volume and CT nasal volume was much smaller than the combined volume of the maxillary and frontal sinuses. The results suggest that AR measurements of the healthy adult nasal cavity are reasonably accurate to the level of the paranasal sinus ostia. Beyond this point, AR overestimates cross-sectional area and provides no quantitative data for sinus volume or ostium size. The effects of paranasal sinuses and acoustic resonances in the nasal cavity are not accounted for in the present AR algorithms.


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