Rhinomanometry and acoustic rhinometry [Summary Statement 42]
Rhinomanometry, a technique that measures functional obstruction to airflow in the upper airway, may be used (1) to obtain objective assessment of nasal congestion, and may be particularly helpful in occupational rhinitis, or in assessing response to therapeutic interventions; (2) to assess the severity of anatomical abnormalities; or (3) to assist in the evaluation of patients with obstructive sleep apnea. 217 Acoustic rhinometry reflects acoustic signals from structures in the nasal cavity, thereby producing an image that represents variations in the cross-sectional dimensions of the nasal cavity.218-220 This produces an approximate nasal cavity volume and identifies the distance to the minimal cross-sectional area from the nares. Measurement by acoustic rhinometry has been validated by comparison to CT and MRI. 221 Using this comparison, there is high correlation for the anterior 2/3of the nasal cavity, but the posterior nasal cavity shows more variance. 222-225 Clinically, acoustic rhinometry may be of value to monitor response and adherence to medical therapy as well as nasal pharyngeal surgical outcome. 226,227Acoustic rhinometry is rapid, safe, and noninvasive; requires minimal patient training and cooperation; and may obviate the need of CT and MRI in some situations, such as when septoplasty and turbinoplasty are considered, as well as for postoperative evaluation.229
As recently listed in a text book for functional rhinoplasty, May 2017:
“AR is a static measurement of nasal dimensions. The measurements obtained are affected by the degree of nasal congestion at the time they are taken. Lee and Most recommend obtaining measurements both before and after applying topical decongestant to determine to what degree mucosal hypertrophy is contributing to the patient’s nasal obstruction”.
As it appears in a position statement with AAO-HNS for nasal turbinate surgery:
“For nasal turbinate surgery, the AAO-HNS  lists an allergy evaluation, rhinomanometry, and acoustic rhinometry as optional tests in the preoperative setting.”
As it appears in the European Academy of Allergy and Clinical Immunology:
“Acoustic rhinometry can be used also to check the impact of long-term medical treatment on nasal blockage due to rhinitis, rhinosinusitis or nasal polyps. It can measure the volume of nasal cavities helping in objective evaluation of nasal polyp size reduction after medical treatment. Specific challenge tests based on the application of allergen onto the nasal mucosa in the allergic patient may show extent of congestion by showing reduced nasal volume. However, it should be stated that acoustic rhinometry, as well as rhinomanometry data on nasal patency do not correlate well with patients’ subjective perception on nasal blockage.”