Clinical applications of acoustic rhinometry

The clinical value of acoustic rhinometry (AR) is its ability to measure the dimensions of the nasal cavity in terms of a curve describing the cross-sectional areas as a function of distance. This curve describes nasal airway patency and gives an impression of the degree of nasal obstruction. The method provides values before and after decongestion which allow to evaluate the cause of the nasal obstruction as mainly skeletal or mucosal. This makes AR a tool for diagnosis and follow-up of treatment in both rhinology and rhinosurgery. Similarly, AR is a reliable method to show the dimensional changes of the nasal cavity before and after a given treatment. In the evaluation of a surgical intervention it is reasonable to use decongested values. Turbinate surgery, septo- and rhinoplasty, orthognatic surgery and paranasal sinus surgery and their influence on the dimensions of the nasal cavity may be reflected by AR. The absolute minimum cross-sectional area, and cross-sectional areas and volumes at fixed distances are the recommended parameters to show dimensional changes after nasal surgery. The predictive value of AR, in relation to nasal obstruction, should have high specificity and sensitivity to be used in a clinical setting. It seems that the single variables do not provide enough information for the diagnosis of obstruction, and it has been stressed that the results should be interpreted together with rhinoscopy and subjective complaints. A statistical model based on questionnaire, rhinoscopic findings and several variables from AR has been proposed to increase the diagnostic specificity and sensitivity of AR.