Size of nostril opening as a measure of intranasal volume.

The anatomy of the human intranasal cavity is complex and anatomical variations are known to affect olfactory functions. Measurement of anatomical variations via delineation of intranasal volume is, however, technically complicated as well as time-consuming. It is well documented that size of various body parts tends to correlate within the same individual. Therefore, in the current study, we explored the relationship between intranasal volume and the size of the nares, with the aim of using the area of the nostril opening as a potential predictor of intranasal volume. Structural whole-brain T1-weighted MR images of 69 healthy volunteers (35 women) were obtained using a 1.5 T standard clinical MRI scanner. The intranasal volume, as well as the area of the nostril opening, were delineated. Our results suggest that the intranasal volume is positively correlated with the area of the nostril opening. Intranasal volume did not differ significantly between men and women although men had significant larger nostril openings. However, the correlation between intranasal volume and nostril opening was not influenced by the subject's gender. In conclusion, it is possible to obtain a good estimate of the intranasal volume using measurements of the nares.