Acoustic rhinometry in humans: accuracy of nasal passage area estimates, and ability to quantify paranasal sinus volume and ostium size.

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.     

Effects of the nasal valve on acoustic rhinometry measurements: a model study.

The influence of nasal valve on acoustic rhinometry (AR) measurements was evaluated by using simple nasal cavity models. Each model consisted of a cylindrical pipe with an insert simulating the nasal valve. The AR-determined cross-sectional areas beyond the insert were consistently underestimated, and the corresponding area-distance curves showed pronounced oscillations. The area underestimation was more pronounced in models with inserts of small passage area. The experimental results are discussed in terms of theoretically calculated "sound-power reflection coefficients" for the pipe models. The reason for area underestimation is reflection of most of the incident sound power from the barrier at the front junction between the pipe and the insert. It was also demonstrated that the oscillations are due to low-frequency acoustic resonances in the portion of the pipe beyond the insert. The results suggest that AR does not provide reliable information about the cross-sectional areas of the nasal cavity posterior to a significant constriction, such as pathologies narrowing the nasal valve area. When the passage area of the nasal valve is decreased, the role of AR as a diagnostic tool for the entire nasal cavity becomes limited.     

Acoustic rhinometry in dog and cat compared with a fluid-displacement method and magnetic resonance imaging.

An increasing number of studies have used acoustic rhinometry (AR) for study of pharmacological interventions on nasal cavity dimensions in dogs and cats, but there have been no attempts to validate AR in these species. This is done in the present study. We compared area-distance relationships of nasal cavities from five decapitated dogs (3.5-41 kg) and cats (3.8-6 kg). AR was compared with magnetic resonance (MR) imaging and a fluid-displacement method (FDM) using perfluorocarbon. AR measured 88% (98-79%) (mean and 95% confidence interval) of nasal cavity volume in dogs determined by FDM and 71% (83-59%) in cats. AR markedly underestimated nasal cavity dimensions when minimum areas were below 0.1 cm2 in dogs and 0.05 cm2 in cats. AR underestimation increased with the severity of the constriction and with distance. Cross-sectional areas in the deeper parts of the cavity measured 76% (99-54%) of FDM in dogs and 52% (66-39%) in cats. AR agreed well with MR, especially in the deeper part of the cavity. MR images showed that the nasal cavities had a very complex structure not expected to be reproduced by AR. MR could not be considered a "gold standard" because definition of the cross-sectional area of the lumen depended critically on subjective choices. FDM produced repeatable measurements and possibly offers the most adequate reference in future evaluation of AR. AR underestimated what we believed were the most correct cross-sectional areas determined by FDM, especially in the deeper part of the dog and cat nasal cavities. Despite these difficulties, AR has been shown to be useful to describe qualitative changes in cross-sectional area.     

Nasal cavity dimensions in guinea pig and rat measured by acoustic rhinometry and fluid-displacement method.

The purpose of the study was to measure nasal passageway dimensions in guinea pigs and rats by use of acoustic rhinometry (AR) and by a previously described fluid-displacement method (FDM) (Straszek SP, Taagehoej F, Graff S, and Pedersen OF. J Appl Physiol 95: 635-642, 2003) to investigate the potential of AR in pharmacological research with these animals. We measured the area-distance relationships by AR of nasal cavities postmortem in five guinea pigs (Duncan Hartley, 400 g) and five rats (Wistar, 250 g) by using custom-made equipment scaled for the purpose. Nosepieces were made from plastic pipette tips and either inserted into or glued onto the nostrils. We used liquid perfluorocarbon in the fluid-displacement study, and it was carried out subsequent to the acoustic measurements. We found for guinea pigs that AR measured a mean volume of 98 mm(3) (95-100 mm(3)) (mean and 95% confidence interval) of the first 2 cm of the cavity. FDM measured a mean volume of 146 mm(3) (117-175 mm(3)), meaning that AR only measured 70% (50-90) of the volume by FDM. For rats, the volume from 0 to 2 cm was 58 mm(3) (55-61 mm(3)) by AR and 73 mm(3) (60-87 mm(3)) by FDM, resulting in AR only measuring 83% (66-100%) of volume by FDM (see Table 2). We conclude that absolute nasal cavity dimensions are underestimated by AR in guinea pigs and rats. This does not preclude that relative changes may be correctly measured. In vivo trials with AR using rats have not yet been published. The FDM is possibly the most accurate alternative to AR for measurements of the nasal cavity geometry in small laboratory animals, but it can only be used postmortem.     

Acoustic reflections during rhinometry: spatial resolution and sound loss

The accuracy ofthe acoustic reflections method for the evaluation of human nasalairway geometry is determined by the physical limitations of thetechnique and also by the in vivo deviations from the assumptions ofthe technique. The present study 1)examines the sound loss caused by nonrigidity of the nasal mucosa andviscous loss caused by complex geometry and its influence on theestimation of the acoustic area-distance function;2) examines the optimal relation between sampling frequency and low-pass filtering, and 3) evaluates advantages of breathingHe-O₂ during the measurements onaccuracy. Measurements made in eight plastic models, withcavities exactly identical to the "living" nasal cavities,revealed only minor effects of nonrigidity of the nasal mucosa. Thiswas confirmed by an electrical analog model, based on laser vibrometryadmittance measurements of the nasal mucosa, which indicated that theerror in the acoustic measurements caused by wall motion isinsignificant. The complex geometry of the nasal cavity per se (i.e.,departure from circular) showed no significant effects on themeasurements. Low-pass filtering of the signal is necessary to cut offcross modes arising in the nasal cavity. Computer simulations andmeasurements in models showed that the sampling frequency should beapproximately four times the low-pass filtering frequency (i.e., twicethe Nyquist frequency) to avoid influence on the result. No advantagewas found for the the use of He-O₂vs. air in the nasal cavity.

     

Clinal variation of maxillary sinus volume in Japanese macaques (Macaca fuscata)

Macaques (genus Macaca) are unique among cercopithecids in that they possess a maxillary sinus, and among anthropoids in that they demonstrate a relatively weak relationship between the size of this sinus and the cranium. To test the hypothesis that extrinsic factors may contribute to maxillary sinus size variation, a sample of 46 Japanese macaque (M. fuscata) crania from known localities were subjected to computed tomography (CT) imaging, and sinus volume and nasal cavity area were analyzed relative to latitude and temperature variables. The results suggest that the environmental factors are significant determinants of nasal cavity size in Japanese macaques, but that the relationships between the environment and maxillary sinus volume (MSV) are probably a passive consequence of changes in the size of the nasal cavity. The sinus shrinks as the nasal cavity expands, due to an increased need to condition inspired air in colder climates. This in turn suggests that the sinus itself does not contribute significantly to upper respiratory function.     

Regional differences in quantities of histochemically detectable mucosubstances in nasal, paranasal, and nasopharyngeal epithelium of the bonnet monkey

Inhaled irritants induce secretory cell hyperplasia in nasal epithelium of animals. To characterize this response histochemically it is first important to know the histochemical character and distribution of epithelial mucosubstance in the normal nasal cavity. An automated image analyzing method was used to detect and quantitate acidic, neutral, and sulfated mucosubstances in the epithelium lining the nasal and paranasal airways of eight bonnet monkeys. Tissue sections 2 micron thick from defined regions of these airways were stained with either alcian blue/periodic acid-Schiff to demonstrate acid and neutral mucosubstances or high iron diamine to demonstrate sulfated mucins. Respiratory epithelium covering maxilloturbinates had the largest volume of stainable mucosubstance per unit surface area of basal lamina, whereas the maxillary sinus epithelium had the least. There was a general anteroposterior increase in the quantity of total epithelial mucosubstance along the septal and lateral walls of the nasal cavity, and there was more acidic than neutral mucosubstance in the posterior nasal airway than in the anterior. Epithelial mucosubstance in the maxillary sinus was predominantly neutral. Therefore, we conclude that there are substantial regional quantitative differences in stainable mucosubstances in the primate nasal epithelium which must be considered when examining nasal mucosa for irritant-induced changes in epithelial mucins.     

Acoustic rhinometry: validation by three-dimensionally reconstructed computer tomographic scans.

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 x CT + b)]. The measuring accuracy using CT as gold standard revealed a mean error at the nasal valve of <0.01 cm(2) (4.52%) and at the nasal isthmus of 0.02 cm(2) (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.     

Enigmatic Diversity of the Maxillary Sinus in Macaques and Its Possible Role as a Spatial Compromise in Craniofacial Modifications

Understanding the evolutionary significance of morphological diversity is a major goal of evolutionary biology. Paranasal sinuses, which are pneumatized hollow spaces in the face, have attracted attention from researchers as one of the most intriguing traits that show unexpected variations. Macaques are one genus of primates that have accomplished adaptive radiation and therefore present an excellent opportunity to investigate the phenotypic diversification process. Using the large data set of computed tomography images of macaques (172 specimens from 17 species), we applied geometric morphometrics and multivariate analyses to quantitatively evaluate the maxillary sinus (one of the largest paranasal sinuses), the outer craniofacial shape, and nasal cavity. We then applied phylogenetic comparative methods to test their morphological interactions, phylogenetic, and ecogeographical significances. The results showed that the relative maxillary sinus size was significantly associated with the relative nasal cavity size and with the zygomaxillary surface shape. The relative nasal cavity size had ecogeographical correlations and high phylogenetic signal, whereas the zygomaxillary surface shapes were ecogeographically and phylogenetically irrelevant. The significant interactions with multiple surrounding traits that have experienced different evolutionary processes probably enable the maxillary sinus to show enigmatic diversity, which is independent of phylogeny and ecology. The pliable nature of the maxillary sinus, which is positioned between the nasal airways and the outer face, may play a role as a spatial compromise in craniofacial modifications.     

An allometric study of the frontal sinus in Gorilla, Pan and Pongo

There is considerable speculation about the role and significance of the paranasal sinuses in the Hominoidea, and this study aims to present new data about an old problem from cephalograms of dried crania. Measurements of frontal sinus volumes were determined for Gorilla gorilla gorilla; G. gorilla beringei and Pan troglodytes. By adopting an allometric approach it was determined that the frontal sinus volume of Gorilla is relatively smaller than that of Pan, and that the frontal sinus of G. g. gorilla is relatively smaller than that of G. g. beringei. Frontal sinus volume scales in a positive allometric fashion relative to skull length. Since the slope is steeper for Pan, frontal sinus volume is increasing at a faster rate than in Gorilla. Sexual dimorphism in frontal sinus volume is present. Thirty crania of Pongo were investigated for evidence of pneumatization of the frontal bone. In no case was secondary invasion of the frontal bone by the maxillary antrum observed. In Gorilla, the nasal cavity volume scales isometrically with skull length. The scaling relationships discussed do not support any 'functional' role of the frontal sinus associated with nasal function but suggest a 'structural' role associated with craniofacial architecture.     

Measurement of nasal patency in anesthetized and conscious dogs.

Experiments were undertaken to characterize a noninvasive chronic, model of nasal congestion in which nasal patency is measured using acoustic rhinometry. Compound 48/80 was administered intranasally to elicit nasal congestion in five beagle dogs either by syringe (0.5 ml) in thiopental sodium-anesthetized animals or as a mist (0.25 ml) in the same animals in the conscious state. Effects of mast cell degranulation on nasal cavity volume as well as on minimal cross-sectional area (A(min)) and intranasal distance to A(min) (D(min)) were studied. Compound 48/80 caused a dose-related decrease in nasal cavity volume and A(min) together with a variable increase in D(min). Maximal responses were seen at 90-120 min. Compound 48/80 was less effective in producing nasal congestion in conscious animals, which also had significantly larger basal nasal cavity volumes. These results demonstrate the utility of using acoustic rhinometry to measure parameters of nasal patency in dogs and suggest that this model may prove useful in studies of the actions of decongestant drugs.     

脊椎动物中的一种解剖学新模型——黄鳝外周嗅觉系统

除单鼻型的圆口类外, 脊椎动物的左、右两侧嗅觉器官和嗅神经皆互为独立地分布于头前端, 而且它们的前鼻孔(外鼻孔)、嗅腔、嗅觉副囊腔(部分鱼具嗅觉副囊)与后鼻孔(或内鼻孔)也都互为相通, 且多呈开放状态。它们还通常具有一个体积相对较大且较稳定的嗅腔, 而嗅上皮则多位于嗅腔的一侧。此外, 鱼类的嗅囊与鼻窝之间通常也无明显间隙。然而, 运用常规的解剖学方法发现, 黄鳝(Monopterus albus)外周嗅觉系统(嗅觉器官和嗅神经)在解剖结构上已发生如下重大变化: (1)虽然具有前、后鼻孔, 但两者互不相通, 而嗅腔仅靠前鼻孔通至外界; (2)两侧嗅囊的末端及两侧嗅神经的前段均分别发生了合并。此外, 在该鱼上还发现:(1)嗅囊为一柔软而扁塌的长管囊结构, 其唯一的开口(即位于前鼻孔球上的前鼻孔)却常呈关闭状, 故此时该嗅腔实际上是一个体积被压扁到最小且暂时被封闭的空间; (2)嗅囊纵向地贴附于长鼻窝的内侧壁上, 它仅占鼻窝的一小部分空间, 故鼻窝显得相对很宽敞; (3)嗅觉副囊不与嗅腔相通, 而与鼻窝共同经后鼻孔通至外界; (4)两侧嗅囊的末端相向地穿越鼻窝内侧壁, 进入筛骨与额骨之间的“筛-额横管”, 在那里发生嗅囊合并;(5)嗅囊壁周缘几乎都内衬着嗅上皮, 且具数个褶窝(说明该嗅囊有扩张的可能)。因此, 黄鳝的这套解剖学特征不同于包括鱼类在内的所有脊椎动物的外周嗅觉系统。研究所发现的黄鳝这套形态学特征不仅为脊椎动物外周嗅觉系统的研究提供了一个独特的解剖学新模型, 同时也为动物进化研究提供了一个有关前、后鼻孔互不相通的进化特例。此外, 研究还依据上述发现提出嗅囊扩张-压缩假说以解释气味媒质进出于黄鳝这种特殊嗅腔的动力学机制。       

Innervation pattern of the gill arches and gills of the carp (Cyprinus carpio)

The innervation pattern of the respiratory gill arches of the carp (Cyprinus carpio) is described. The gill region is innervated by the branchial branches of the glossopharyngeal and vagal nerves. Each branchial nerve divides at the level of or just distal to the epibranchial ganglion into: 1) a pretrematic branch, 2) a dorsal pharyngeal branch, and 3) a posttrematic branch. The dorsal pharyngeal branch innervates the palatal organ in the roof of the buccal cavity. The pretrematic and posttrematic branches innervate the posterior and anterior halves, respectively, of the gill arches bordering a gill slit. Each branch splits into an internal and an external part. The internal bundle innervates the buccal side of the gill arch, including the gill rakers. The external bundle terminates in the gill filaments. The epibranchial motor branch, a small nerve bundle containing only motor fibers, circumvents the ganglion and anastomoses distally with the posttrematic branch. The detailed course and branching patterns of these branches are described.     

Nasal cavities and paranasal sinuses in newborns and children]

The paranasal or accessory nasal sinuses begin their development as evaginations of the mucosa during the 3rd and 4th fetal months, but undergo their major expansion after birth according to the development of the facial cranium and the teeth. While in the newborn the sphenoidal and frontal sinuses are still only predispositioned, the ethmoidal labyrinth and particularly the maxillary sinus are of appreciable size. In the 4-year-old the frontal and sphenoidal sinuses are already developed and in the 12-year-old the paranasal sinuses reach their final form and a size equivalent to the adult.     

Acoustic rhinometry: evaluation of nasal cavity geometry by acoustic reflection

To study the geometry of the nasal cavity we applied an acoustic method (J. Appl. Physiol. 43: 523-536, 1977) providing an estimate of cross-sectional area as a function of distance. Acoustic areas in a model constructed from a human nasal cast, in the nasal cavity of a cadaver and in 10 normal subjects and two patients with well-defined afflictions of the nasal cavity, were compared with similar areas obtained by computerized tomography (CT) scans, a specially developed water displacement method, and anterior rhinomanometry. We found a coefficient of variation of the areas of less than 2% by the acoustic method compared with 15% for the rhinomanometric measurements. Acoustic areas correlated highly to similar areas obtained by CT scanning (r = 0.94) and by water displacement (r = 0.96). In two patients the acoustic method accurately outlined, respectively, a tumor in the nose and a septum deviation. It is concluded that this method provides an accurate method for measuring the geometry of the nasal cavity. It is easy to perform and is potentially useful for investigation of physiological and pathological changes in the nose.     

Anatomy of the nasal cavity and paranasal sinuses in Aegyptopithecus and early Miocene African catarrhines

Neontological comparisons suggest that paranasal sinus anatomy is diagnostic of several catarrhine clades such as Cercopithecoidea, Hominoidea, Homininae, and Ponginae. However, while the loss of sinuses in cercopithecoids is generally recognized as a derived condition, determining the polarity of character-state changes within noncercopithecoid catarrhines requires knowledge of the primitive catarrhine condition. To address this problem, the paranasal sinus anatomy of Aegyptopithecus and several early Miocene catarrhines was investigated. Two partial facial skeletons of Aegyptopithecus were subjected to computed tomography in order to reveal their internal anatomy. These data were compared with facial and palatal specimens of Proconsul, Limnopithecus, Dendropithecus, Rangwapithecus, and Kalepithecus in the National Museums of Kenya in Nairobi, and to wet and dry specimens of living taxa. Results confirm that cercopithecoid paranasal anatomy is derived, and reveal that the sinus anatomy of stem catarrhines included a hominoid-like maxillary sinus as well as an ethmofrontal system like that of hominines. Accordingly, these two features do not constitute evidence for the hominoid, hominid, or hominine status of any fossil species. Conversely, the absence of the ethmofrontal sinus system in Sivapithecus and Pongo is synapomorphic. In addition, features of the nasal cavity of Limnopithecus and Kalepithecus support previous suggestions that these taxa are stem catarrhines rather than hominoids.     

A 1H NMR comparison of the met-cyano complexes of elephant and sperm whale myoglobin. Assignment of labile proton resonances in the heme cavity and determination of the distal glutamine orientation from relaxation data

The met-cyano complex of elephant myoglobin has been investigated by high field 1H NMR spectroscopy, with special emphasis on the use of exchangeable proton resonances in the heme cavity to obtain structural information on the distal glutamine. Analysis of the distance dependence of relaxation rates and the exchange behavior of the four hyperfine shifted labile proton resonances has led to the assignment of the proximal His-F8 ring and peptide NHs and the His-FG3 ring NH and the distal Gln-E7 amide NH. The similar hyperfine shift patterns for both the apparent heme resonances as well as the labile proton peaks of conserved resonances in elephant and sperm whale met-cyano myoglobins support very similar electronic/molecular structures for their heme cavities. The essentially identical dipolar shifts and dipolar relaxation times for the distal Gln-E7 side chain NH and the distal His-E7 ring NH in sperm whale myoglobin indicate that those labile protons occupy the same geometrical position relative to the iron and heme plane. This geometry is consistent with the distal residue hydrogen bonding to the coordinated ligand. The similar rates and identical mechanisms of exchange with bulk water of the labile protons for the three conserved residues in the elephant and sperm whale heme cavity indicate that the dynamic stability of the proximal side of the heme pocket is unaltered upon the substitution (His----Gln). The much slower exchange rate (by greater than 10(4] of the distal NH in elephant relative to sperm whale myoglobin supports the assignment of the resonance to the intrinsically less labile amide side chain.     

Reconstruction of proximal nasal defects with island composite nasal flaps

There are few local nasal flap options for repair of proximal nasal defects. Absence of suitable donor sites and the large dimensions of the defects limit the use of local nasal flaps in this region. Regional paranasal flaps may not be suitable in these cases because of color, texture, and donor-site scars. The composite procerus muscle and nasal skin flap, which is vascularized by the dorsal nasal branch of the angular artery, can be a useful treatment modality for proximal nasal reconstruction. Seven patients were successfully treated using the composite nasal flaps. The maximal size of the defects was 2.4 cm. In one case, the composite nasal flap was readvanced to close a new defect resulting from reexcision. The composite nasal flap has several advantages in reconstruction of proximal nasal defects. Reconstruction is performed with the same tissue and the donor defect is closed primarily. The composite nasal flap can be moved in multiple directions and has great mobility to reach every point of the proximal part of the nose with axial blood supply. Furthermore, it can be easily readvanced without additional morbidity in case of reexcision.     

Wood exposure and smoking: association with cancer of the nasal cavity and paranasal sinuses in British Columbia.

A case-control study of 121 men seen for cancer of the nasal cavity or paranasal sinuses in British Columbia between 1939 and 1977 showed increased relative risks associated with occupations involving exposure to wood (2.5) and with smoking (4.9). The occupations involved were chiefly forestry and carpentry. Both risk factors appeared to be associated with the principal sites within the nasal cavity paranasal sinuses and with most histologic subtypes of cancer.     

Focus: Rare Disease: Sinonasal Glomangiopericytoma: Review of Imaging Appearance and Clinical Management Update for a Rare Sinonasal Neoplasm

Introduction: Glomangiopericytoma (GPC) is a rare tumor in the nasal cavity or paranasal sinuses with low malignant potential. Initially deemed a hemangiopericytoma, in 2005 it was classified as a distinct entity by the World Health Organization (WHO). Case Presentation: A male patient in his early 60s presented with new-onset right arm and leg weakness/numbness, who was incidentally found to have a left ethmoid sinus mass with extension in the olfactory fossa. On CT and MRI, the mass enhanced with well-defined borders and eroded the bone, but without dural enhancement. The mass was surgically excised, and pathology confirmed the diagnosis of glomangiopericytoma by microscopic appearance and staining. Discussion: Glomangiopericytoma has less than 0.5% incidence of all neoplasms of the sinonasal cavity, making it rare. Most diagnosed patients are in their 6th or 7th decade of age, with a slight female predominance. Treatment is complete surgical excision, with excellent prognosis, although there is up to 17% local recurrence. Despite the non-specific appearance on CT and MRI, imaging can help provide differential diagnosis, tumor extent, size, and reassuring non-aggressive characteristics of the tumor prior to surgery. GPC tumors are relatively resistant to radiation and chemotherapy. Conclusion: It is important to recognize glomangiopericytoma in the differential of masses of the nasal cavities or paranasal sinuses, as they rarely warrant aggressive treatment beyond local excision. Each reported case of glomangiopericytoma helps to build guidance for imaging and treatment since GPC is rare and not well-represented in the medical literature.