Value of acoustic rhinometry for measuring nasal valve area.

OBJECTIVE To assess the validity of acoustic rhinometry for measuring nasal valve area in human subjects. STUDY DESIGN A comprehensive study that compared acoustic rhinometry data with computed tomography findings from scans obtained perpendicular to the acoustic axis and perpendicular to the floor of the nose. METHODS Fifty nasal passages of 25 healthy adults with no nasal disease were examined by acoustic rhinometry and computed tomography. In each case, the area of the nasal valve as measured by acoustic rhinometry was compared with the area calculations from computed tomography sections taken in two different coronal planes, one perpendicular to the acoustic axis and one perpendicular to the floor of the nose. Computed tomography slices perpendicular to the floor of the nose were obtained at two different locations, a specific distance from the tip of the nose and a specific distance from the anterior nasal spine. RESULTS There was a significant correlation between the nasal valve areas determined by acoustic rhinometry and computed tomography when imaging was obtained perpendicular to the acoustic axis. In contrast, when scanning was obtained perpendicular to the straight axis of the floor of the nose, the correlations between the acoustic rhinometry and computed tomography data were weak. CONCLUSIONS When any type of imaging is used for comparison with nasal valve areas determined by acoustic rhinometry, the cross-sections should be perpendicular to the acoustic pathway. The results of the study show that acoustic rhinometry is a valuable method for measuring nasal valve area.