Anatomic correlates of acoustic rhinometry as measured by rigid nasal endoscopy

Acoustic rhinometry (AR) evaluates the cross-sectional areas and volume of the nasal cavity through acoustic reflections. Successive valleys displayed on an AR graph are believed to correspond to anatomic landmarks. To assess the anatomic accuracy of AR, we performed AR and endoscopic measurements w ith a rigid endoscope in 85 normal human subjects after topical decongestio n, Endoscopic measurements were recorded for distances between the midcolum ella and the nasal valve, the anterior end of the inferior turbinate, the a nterior end of the middle turbinate, the midportion of the middle turbinate , and the posterior nasopharynx, The first AR valley most closely correspon ded with endoscopic measurements of the nasal valve, The second valley had a mean value that corresponded with the anterior end of the inferior turbin ate. The third valley matched best with the values of the anterior end of t he middle turbinate, Nasopharyngeal measurements by each modality yielded a good agreement. AR appears to correspond to nasal anatomic landmarks but n ot in an exact point-to-point manner.