The nasal valve: new insights on the static and dynamic NV with MR-imaging.

Abstract

We assessed the static nasal valve angle with MR imaging in healthy subjects and evaluated the complex mechanism of nasal valve dynamics during physiologic and forced inspiration. In 17 healthy subjects, measurements of the static nasal valve angle were conducted on MR scans, using a TSE Axial T2-weighted sequence and a 3mm slice thickness. The dynamic changes of nasal valve movement were detected using MR Cine-imaging techniques. The static median angle of the nasal valve was found to be 28.6° with a range of 12.7°-39.3°. The median degree of nasal valve collapse during forced inspiration was 68% (range 20-99%) of the baseline (static nasal valve angle). In the moderately forced inspiration (3s) the median nasal valve angle declined to 76% of the baseline angle (range 42-100%). In the physiologic or unforced inspiration, the median nasal valve angle was reduced to 86.3% of the baseline angle (range 52-100%). MRI, as a non-invasive tool, is a reliable method for evaluation of the static nasal valve angle and for the illustration of the complex nasal valve dynamics.