Rhinomanometry and acoustic rhinometry tests to assess intranasal dimensions and cross sectional area. It measures air pressure and the rate of the airflow during breathing. The measurements are then used to calculate nasal airway resistance.
Acoustic rhinometry uses a reflective sound signal to measure the cross-sectional area and volume of the nasal passage.
Rhinomanometry gives a functional measure of the pressure / flow during the respiratory cycle.
Nasal obstruction leads to increased values of nasal resistance. Rhinomanometry may be used to measure only one nostril at a time (anterior rhinomanometry) or both nostrils simultaneously (posterior rhinomanometry).
We perform this test on the patient pre and post a nasal decongestant spray. The pressure sensing tubes are placed in the nostril while the contralateral nostril is left opened.
When the measurements are performed before and after the nasal decongestant spray, the differences in resistance can be attributed to nasal mucosal congestion. If there is no significant improvement after decongestant, the anatomical abnormality is suspected that is blocking normal airflow.
If improvement occurs after the nasal decongestant spray it may suggest a mucosal congestion such as rhinitis.