Acoustic rhinometry used as a method to monitor the effect of intramuscular injection of steroid in the treatment of nasal polyps

Acoustic 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 as a 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.     

Accuracy of measurement of acoustic rhinometry applied to small experimental animals

Nasal obstruction is one of the major symptoms of allergic rhinitis. In the study of the mechanism of nasal obstruction, experiments on animal are useful. In adult humans, acoustic rhinometry has been used to evaluate nasal obstruction by determining nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. We modified the equipment used on humans to assess dimensions of nasal airway geometry of small experimental animals. The purpose of this study was to investigate the accuracy of measurement of the modified acoustic rhinometry applied to small experimental animals using nasal cavity models and guinea pigs. Measurement of the nasal cavity models (made of cylindrical silicone tubes) showed that the acoustic rhinometry estimated 85.5% of actual area and 79.0% of actual volume. In guinea pigs, nasal cavity volume determined by the acoustic rhinometry was 73.7 +/- 20.0% of actual volume. The actual volume was estimated by impression material instilled into the nasal cavity of the animals (IM volume), and volume determined by acoustic rhinometry significantly correlated with IM volume. Furthermore, there was a significant negative correlation between the volume and nasal airway resistance in guinea pigs. Measurement of the nasal airway resistance is the method frequently used in the evaluation of the nasal obstruction in guinea pigs. These results suggest that acoustic rhinometry is useful in evaluating nasal obstruction in small experimental animals.     

Acoustic rhinometry in nasal provocation test in perennial allergic rhinitis

Acoustic rhinometry is one method to evaluate nasal geometry by an acoustic reflection technique. The aim of this study was to investigate the changes in acoustic rhinometry after nasal provocation in patients with exclusively perennial allergic rhinitis. In 19 patients, acoustic rhinometry and active anterior rhinomanometry were performed before and after nasal provocation test. There was a statistically significant nasal flow reduction measured by active anterior rhinomanometry after nasal provocation (p < 0.05) and a median symptom score of four points, both indicating a positive response to nasal provocation. On the other hand, there was no statistically significant change in the values of acoustic rhinometry after nasal provocation (p > 0.05). In patients with exclusively perennial allergic rhinitis, acoustic rhinometry does not seem to significantly change after nasal provocation. In contrast, active anterior rhinomanometry values decreased significantly after nasal provocation. The presented results indicate that acoustic rhinometry does not seem to be a diagnostic method superior to active anterior rhinomanometry in this context.     

The role of acoustic rhinometry in the evaluation of the volume of nasopharynx before and after adenoidectomy]

OBJECTIVE: To determine the type of acoustic rhinometry curve in different kinds of nasal and nasopharyngeal diseases and the role of acoustic rhinometry in the evaluation of the changes of the volume of nasopharynx before and after adenoidectomy. METHODS: One hundred and fifty-one patients with nasal and nasopharyngeal diseases, including rhinitis, nasal polyps, obstructive sleep apnea syndrome, palatoschisis, atrophic rhinitis, adenoid vegetation, perforation of nasal septum, carcinoma of nasopharynx, and stricture of nasal limen, were measured with acoustic rhinometry. Meanwhile, 15 patients with adenoid vegetation were measured before and after adenoidectomy, the changes in volume recorded by acoustic rhinometry were compared with the adenoid volume obtained by the method of displacement. RESULTS: Acoustic rhinometry curve can be divided into normal and abnormal curves and the abnormal curves can be divided into four types according to the site of changes. Acoustic rhinometry curve altered with the changes in character, degree and site of nasal and nasopharyngeal diseases and could return to normal after surgery or medical treatment. The volume of nasopharynx of adenoid vegetation patients was significantly smaller than that of the normal control and it rose significantly and became closed to normal after adenoidectomy. The volume of adenoid and the calculated changes in volume of the nasopharynx was found to be interrelated and highly significant(r = 0.87, P < 0.001). CONCLUSION: The results indicate that acoustic rhinometry curve is a useful method in the assistant diagnosis and judgment of therapeutic effectiveness of many kinds of nasal and nasopharyngeal diseases and can provide reference for the evaluation of the volume of adenoids.     

Physiological change in nasal patency in response to changes in posture, temperature, and humidity measured by acoustic rhinometry

BACKGROUND: Acoustic rhinometry has been used to assess nasal patency and to calculate nasal cavity volume. This study used acoustic rhinometry to assess changes in nasal patency after alterations in posture, unilateral mechanical obstruction, temperature, and humidity. METHODS: Eight healthy adult volunteer subjects underwent acoustic rhinometry during the following conditions: (1) sitting position (control), (2) supine position, (3) left lateral recumbent position, (4) nostril unilaterally mechanically blocked, (5) ice pack on neck, (6) drinking cold water, (7) drinking hot water, (8) nasal nebulizer, and (9) oxymetazoline decongestant. RESULTS: Two distinct patterns emerged based on the total nasal cavity volumes in response to the decongestant. Subjects with initial unilateral nasal cavity volumes near the mean had an expected increase in total volume after the topical decongestant administration. There were two subjects with initial volumes of 1 SD above the mean that had a paradoxical decrease in total volume in response to the decongestant. In all subjects, there was a significant decrease in the volume of each of the nasal cavities in response to ingestion of hot water at 1 minute. There was a significant decrease in the volume of the smaller of the two nasal cavities in response to nebulizer treatment and hot water ingestion at 5 minutes. Total nasal cavity volume changes were not significant for any of the variables. CONCLUSION: Changes in nasal cavity volumes were detected by acoustic rhinometry after alterations in posture, unilateral mechanical obstruction, temperature, and humidity. Nebulizer treatment and hot water ingestion caused a significant decrease in nasal volume. The nose of a healthy patient was able to adapt to environmental and physiological changes to maintain a consistent total nasal volume within 15 minutes.     

Prevention of relapses of nasal polyposis with intranasal triamcinolone acetonide after polyp surgery: a prospective double-blind, placebo-controlled, randomised study with a 9-month follow-up

Clin. Otolaryngol. 2012, 37 , 117–123 Objective:  To determine whether intranasal triamcinolone acetonide prevents the regrowth of nasal polyps after polyp surgery. Study design:  Randomised, double‐blind, placebo‐controlled, prospective study. Setting:  Helsinki University Central Hospital. Participants:  Sixty patients with nasal polyps entered the study. Patients were included upon arrival for elective polyp operations determined according to our standard clinical criteria. The recurrence of nasal polyposis was followed up for 9 months after surgical treatment at 3‐month intervals. Main outcome measures:  Anterior rhinoscopy, nasal endoscopy, olfactory threshold measurement, active anterior rhinomanometry and acoustic rhinometry were performed at every follow‐up visit. Results:  On the whole, there was a significant inter‐group difference in the change in polyp size of acetylsalicylic acid (ASA)‐tolerant patients during the follow‐up. In patients with acetylsalicylic acid intolerance, there was no inter‐group difference (P = 0.28). No significant differences were noted for nasal resistance, nasal cavity volume, sense of smell and nasal symptoms. Conclusion:  Triamcinolone acetonide prevents regrowth of nasal polyps after polyp surgery in acetylsalicylic acid‐tolerant patients, but not in acetylsalicylic acid‐intolerant patients.     

A validation study of nasal spectroscopy: Rhinolux

This study is the first to validate the Rhinolux against acoustic rhinometry in detecting nasal mucosal swelling when changing body position from sitting to supine. The Rhinolux (Rhios GmbH, Germany) is a new device using a light-absorption technique called nasal spectroscopy and to measure changes in nasal blood volume as a sign of nasal mucosal swelling in real time. The relationship between the changes in nasal blood volume measured with the Rhinolux and changes in nasal mucosal swelling has however, not previously been validated objectively. To evaluate this relationship we compared the Rhinolux to acoustic rhinometry following the change in body position from sitting to supine. The study population consisted of 20 healthy subjects (7 women, 13 men, mean age 34.7 ± 9.3 years). The Rhinolux was applied sitting in the upright position followed by 5 min in the supine position. Acoustic rhinometry was measured sitting in the upright position and after 5 min in the supine position. In seven subjects the measurements were repeated on three different days to assess the repeatability. The mean change from baseline in minimal cross sectional area ΔMCA measured with acoustic rhinometry was −0.12(±0.19) cm² (right + left side), P = 0.013 but ΔE (change in light extinction from baseline) measured with the Rhinolux was unchanged 0.02(±0.18) optical densities (OD), P = 0.56. There was no correlation between ΔE and ΔMCA r = 0.028, P = 0.9. The mean ΔE result from repeated measurements on different days was 0.05(±0.08) OD, P = 0.09 and the ΔMCA was −0.1(±0.11) cm², P = 0.02. This study showed that the changes in nasal blood volume measured with the Rhinolux did not reflect changes in nasal mucosal swelling measured with acoustic rhinometry when changing body position from sitting to supine. The results indicate that the utility of the Rhinolux in assessing nasal mucosal reactions has to be evaluated further.     

Nasal passage patency in patients with allergic rhinitis measured by acoustic rhinometry: nasal responses after allergen and histamine provocation

We investigated nasal passage patency after allergen and histamine provocation in patients with allergic rhinitis by acoustic rhinometry. In total, 75 outpatients with allergic rhinitis were studied. The threshold of nasal hypersensitivity to histamine was measured by the 10 μl instillation of serial 10-fold dilution in the ipsilateral nasal cavity. Nasal provocation testing to specific antigen was applied to the anterior part of inferior turbinate in bilateral sides in sitting position. Measurement of nasal patency by acoustic rhinometry was repeated three times in each nasal cavity. The minimal cross-sectional area and total volume of nasal cavity were measured in an individual subject. The minimal cross-sectional area and total volume in the histamine challenged-side significantly decreased on the 10⁻², 10⁻¹, 10⁻⁰ of end point, and up to 30 min after challenge with the threshold dose, but not in the unchallenged side. This means acoustic reflection technique is sensitive at least 100-fold in comparison with classical method like findings by anterior rhinoscopy and symptom scores. Nasal passage patency after bilateral allergen provocation showed predominant in the unilateral side, suggesting the cross over-reflex effects.It was concluded that acoustic rhinometry is one of the highly quantitative and sensitive method which can observe the change of nasal congestion.     

鼻内镜手术疗效综合评价

目的 探讨鼻内镜手术对慢性鼻窦炎及鼻息肉疗效的综合评价方法.方法 采用声反射鼻腔测量系统、前鼻测压计、T＆T嗅觉计定量检查法和术区黏膜评分法,对46例慢性鼻窦炎及鼻息肉患者鼻气道阻力、嗅觉、鼻腔术区黏膜形态进行测试.结果 鼻内镜手术后患者的鼻气道通气、嗅觉有明显好转;术后鼻腔、黏膜状况与功能恢复有显著相关性.结论 鼻气道阻力、嗅觉功能测试、鼻声反射检查、术区黏膜评分检测作为手术前后鼻功能的检测手段,可对术后疗效进行客观的综合评价.     

Acoustic rhinometry, used as a method to demonstrate changes in the volume of the nasopharynx after adenoidectomy

Acoustic rhinometry is a method of investigating the geometry of the nasal cavity and the nasopharynx. An acoustic impulse is transferred to the nasal cavity and the reflected signal is analysed expressing the cross-sectional area in the nasal cavity and the nasopharynx as a function of the distance from the nostril. The method provides an accurate and objective measurement of the geometry of the nasal cavity and the nasopharynx in a non-invasive way. In a series of 20 children, age range 4-16 years, it has been possible to demonstrate the changes in the volume of the nasopharynx after adenoidectomy. The relation between the volume of the adenoid and the calculated change of volume in the nasopharynx is found to be proportional and highly significant (P = 0.0005). It is concluded that acoustic rhinometry, which is very easy to perform, gives a reliable, objective measurement of the amount of adenoid tissue in the nasopharynx. The results from these and future studies may help reduce the number of unnecessary adenoidectomies.     

Reference values for acoustic rhinometry in decongested school children and adults: the most sensitive measurement for change in nasal patency

INTRODUCTION: Only a limited reference material for acoustic rhinometry (AR) exists for school children most often calculated as the minimum cross-sectional area (MCA) in the non-decongested nose. We want to establish a set of reference values for MCA and nasal volumes for both adults and children and include values also for the decongested nose and determine the most sensitive measurement for change in nasal patency. METHOD: Data from two studies were used; one comprising of 53 (20M, 33F) school children, age 9-11 years, and one comprising 146 (127M, 19F) healthy workers in the wood industry. Measurements by acoustic rhinometry were done before and after decongestion with two puffs of oxymethazoline nasal spray (1 mg/ml). RESULTS: We found the decongested nasal volume (2-5 cm) to be 3.71 cm3 (3.58-3.84) in school children and 5.44 cm3 (5.21-5.67) in adults. We found the volume from 2-5 cm into the nasal cavity to be the most sensitive measure of change in nasal patency by decongestion, and MCA to be the least sensitive in both adults and children. DISCUSSION: A larger study population of children, covering a broader range of age, is needed to stratify for gender and height. Our data in adults are in accordance with previous findings. CONCLUSION: We have provided a reference material for acoustic rhinometry in school children and adults. Future evaluation of change in nasal patency should contain information about nasal volume from 2-5 cm into the nasal cavity and not just MCA in adults and school children.     

Nasal airway measurements in children treated by rapid maxillary expansion

BACKGROUND: Rapid maxillary expansion is an orthodontic procedure that is commonly used to widen the maxilla. It is generally admitted that this technique is effective to correct palate narrowing, whereas there has not been agreement on the effect of this procedure in nasal parameters. The availability of a reliable and objective technique to assess the geometry of nasal cavities, such as acoustic rhinometry, stimulated the present investigation. METHODS: Twenty-seven children, undergoing rapid maxillary expansion, were evaluated by rhinomanometry and acoustic rhinometry. Postero-anterior radiographs were taken in 15 patients for cephalometric measurements. Examinations were performed before expansion treatment and after 12 month follow-up and compared to the measurements obtained from an untreated control group. RESULTS: With regard to rhinomanometry, we recorded a significant reduction in nasal airway resistance (NAR) after the orthodontic procedure only in decongestion. Using acoustic rhinometry, we found a significant increase in total minimum cross-sectional areas (TMCA) and total nasal volume (TNV) after the expansion both in basal and decongested conditions. Also, nasal cavity width and interzygomatic distance had a significant mean increase after the treatment. Comparison of measures between the control group and the treated group showed that the increase in TMCA and TNV, as well as the decrease in NAR, were significantly greater in the treated group in both basal and decongested conditions. CONCLUSION: We demonstrated that rapid maxillary expansion is an effective procedure in widening nasal cavities with respect to an untreated control group and that the reported improvement in nasal breathing after palatal expansion, is a consequence of an increase in nasal size.     

声反射鼻测量计在鼻畸形患者中的应用

目的研究声反射鼻测量计在鼻畸形患者术前评价中的应用价值。方法因鼻病引起鼻畸形患者（鼻畸形组）及无鼻病健康志愿者（对照组）各15例进行声反射鼻测量计测试,记录鼻腔最小横截面积（nasal minimal cross-sectional area,NMCA）、鼻腔容积（nasal cavity volume,NCV）,NMCA至前鼻孔的距离（distance of the minimal cross-sectional area to the nostril,DCAN）及鼻阻力（nasal resistance,NR）,并进行统计学分析。结果对照组左、右侧鼻腔NMCA、DCAN、NCV、NR差异均无统计学意义（P〉0．05）：鼻畸形组阻塞侧与非阻塞侧NMCA、DCAN、NCV、NR差异有统计学意义（P〈0．001）：鼻畸形组阻塞侧NCV、NR、NMCA均明显小于对照组（P〈0．001）;NMCA和NCV与NR呈反比,而与DGAN无明显相关性（P〉0．05）。结论声反射鼻测量计在鼻畸形患者术前评价中具有重要作用,对鼻畸形患者鼻腔功能及几何形态的评估可为手术提供重要的临床价值。     

Validation of acoustic rhinometry by using the Cavalieri principle to estimate nasal cavity volume in cadavers

The ability of acoustic rhinometry to provide valid estimates of nasal cavity volume has been tested using cadaveric heads. Values obtained for the cavities in five intact heads were compared with unbiased estimates of the volumes of the same specimens. An unbiased estimate is one which does not depart in a systematic manner from the true value. Here, unbiased estimates were made by applying the Cavalieri principle to uniform random samples of 4–7 macroscopic slices per specimen. Using acoustic rhinometry, the mean volume (left and right sides combined) amounted to 31.3 ml with a co-efficient of variation of 77%. On the same specimens, the Cavalieri estimate of mean volume (both cavities plus the adjacent nasopharynx) was 31.1 ml (66%). There was a significant and positive correlation between the two data sets (correlation co-efficient 0.97). Repeated acoustic measurements on the same cavities gave a measuring error of about 4%. We conclude that acoustic rhinometry can provide valid and efficient estimates of the volume of the nasal cavity plus nasopharynx.     

Nasal nitric oxide is independent of nasal cavity volume.

This study was performed to evaluate the relationship between nasal nitric oxide (NO) and changes in nasal cavity volume resulting from the topical application of xylometazoline and saline and between upright and supine posture. Nasal NO was measured using a fixed high flow technique that avoids contamination with lower airways NO. In nine healthy subjects nasal NO concentration was measured by a rapid response chemiluminescent analyzer. A tapered tube was inserted in one nostril, into which room air was insufflated to produce a constant flow of 100 mL/second; another tube was inserted into the opposite nostril for NO sampling (air exit side). Subjects were instructed to keep the vellum closed while NO was sampled through a sideport connected to the analyzer. Nasal cavity volume was measured by acoustic rhinometry from a segment of the acoustic pathway, 2 to 5 cm from the nostril. Nasal cavity volume and NO measurements were made at baseline, 15 minutes, and 60 minutes after intervention (administration of saline 0.9%, xylometazoline or posture changes on 3 consecutive days). Xylometazoline produced a significant increase in nasal cavity volume, together with a significant reduction in NO level at 15 and 60 minutes after intervention. In addition, the change from seated to supine position decreased the total nasal volume significantly, but without changes in nasal NO. No correlation was found between the magnitudes of changes in nasal NO and the changes in nasal volume. Topical application of xylomethazoline resulted in increased nasal cavity volume and reduced NO output. In contrast to previous published reports, a technique using high flow rate insufflation demonstrated an abscence of correlation between the magnitudes of changes in nasal NO and nasal cavity volume brought about by decongestant, saline, or posture.     

Semi-automatic segmentation of computed tomographic images in volumetric estimation of nasal airway

The objective of this study was to determine nasal cavity volumes and cross-sectional profiles from segmented coronal high-resolution computed tomography (HRCT) images. Pathological mucosal changes and congenital sinonasal variants were quantitated and three-dimensional (3D) images for determining sinonasal airway diseases evaluated by using the new semiautomatic segmentation software, Anatomatic. Anterior to posterior cross-sectional profiles of the sinonasal airway were obtained from acoustic rhinometry and segmented coronal HRCT images and compared in five patients having complaints of nasal obstruction and chronic sinusitis. Results showed that accurate volumes of air spaces in the nasal cavity and paranasal sinuses were obtained. When compared, the cross-sectional profiles of the nasal cavities obtained from acoustic rhinometry and the segmentation technique were similar in the anterior portion, but differed in the posterior portion. The results obtained by coronal HRCT and segmentation were more reliable than those produced with acoustic rhinometry. 3D images acquired from segmented images were found to help make a good pre-operative assessment of the whole sinonasal compartment. Segmentation and volumetric analysis using the Anatomatic technique also proved to be well suited to the evaluation of the nasal cavity and paranasal sinus geometry in patients with sinonasal diseases. Received: 5 March 1998 / Accepted: 9 June 1998     

Validation by fluid volume of acoustic rhinometry before and after decongestant in normal subjects

To validate the measurement of nasal volume by acoustic rhinometry, acoustic rhinometry (AR) measures before and after decongestion were compared to a reference volume measurement in 10 healthy volunteers over 3 visits each. The reference method was hydraulic infusion with manometry, involving slow constant-rate infusion of isotonic saline into each nasal cavity while the subject was appropriately positioned. Consecutive 10 mm nasal segments were measured, and hydraulic volume derived. AR volume and hydraulic volume measures were compared. Within subject reproducibility of hydraulic volume and AR volume measures over 3 study days was better than 16% and 11%, respectively. Pre-decongestant, highly significant correlations between AR volume and hydraulic volume in the 20-40 mm segment were found. The mean ratios of AR volume/hydraulic volume ranged from 1.01-1.14. Post decongestant, significant correlations were found in the 30-50 mm segments. The mean AR volume/hydraulic volume ratios were significantly lower (0.88-1.03). Hence, the magnitude of the AR volume change after decongestant was less than the hydraulic volume change (ratio range 0.8 to 1.01), but there were still significant correlations between hydraulic volume and AR volume in the 20-50 mm segments of the cavity. Since hydraulic volume is expected to be similar to anatomical nasal volume, we conclude that changes in AR volume before and after vasoconstriction are similar to anatomical changes in nasal vasculature. AR volume measurements provide a sensitive, reliable and accurate assessment of vasoactive drugs in the nasal cavity.     

Acoustic rhinometry evaluation of nasal response to histamine and antigen in guinea pigs

The effects of antigen and histamine on the changes of nasal passage patency in 112 guinea pigs with or without allergic rhinitis were evaluated by acoustic rhinometry. The percent change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction of 31.10 +/- 4.11% at 10 minutes and 31.10 +/- 4.11% at 30 minutes after antigen challenge in sensitized guinea pigs. The pretreatment with ketotifen, an H1-histamine receptor antagonist as well as mast cell stabilizing drug, blocked dose-dependently the effects of antigen on those changes in volume. Furthermore, instillation of 10(4) micrograms/mL histamine reduced significantly nasal passage patency to 33.77 +/- 4.63% at 10 minutes and 42.76 +/- 3.32% at 30 minutes after challenge compared with that before challenge and ketotifen inhibited the effects of histamine, which indicated that histamine is an important mediator of allergic upper airway responses in guinea pigs. These results show that acoustic rhinometry is a useful technique to assess the nasal blockade in allergic guinea pigs.     

Nasal airway volumetric measurement using segmented HRCT images and acoustic rhinometry

Semiautomatic segmentation methods using High Resolution Computed Tomography (HRCT) or Magnetic Resonance Imaging give accurate and reproducible volumetric measurements in various intracranial diseases. In this prospective study, for the first time in literature, with the help of a new semiautomatic segmentation technique and coronal HRCT, we correlated the volumes and cross-sectional areas of the nasal cavity with those obtained by clinical acoustic rhinometry in 14 patients with chronic sinusitis. The measurements obtained by both techniques showed statistically significant correlations between volumes in the anterior and middle parts, but statistically poor correlations between the volumes in the posterior part of the nasal cavity. Coronal HRCT and our new microcomputer applicable semiautomatic segmentation software proved compatible with daily clinical practice. Based on the promising results of our study, we recommend the use of this technique in the validation studies of acoustic rhinometry and in complicated cases as a complementary examination in the evaluation of nasal cavity.     

Acoustic rhinometry: values from adults with subjective normal nasal patency.

The nose with normal feeling of nasal patency, and no gross structural changes has been described in 82 individuals by acoustic rhinometry. Curves for one and both sides of the nasal cavity and before and after decongestion have been recorded. We have found that the minimal cross-sectional area (MCA) is located anteriorly in the nasal cavity; in some subjects it is localized at the head of the inferior turbinate and in other subjects more anteriorly at the nasal valve. After decongestion MCA moves even more anteriorly. Beyond the MCA the dimension of the nasal cavity increases, with maximal effect of decongestion at 4 cm from nostrils. Decongestion increases the total volume of the nasal cavity by 35%.