RELATION BETWEEN CT SCAN FINDINGS AND HUMAN SENSE OF SMELL

Symptom questionnaires were obtained from 106 patients immediately bef ore nasal and sinus computed tomography scans at the Johns Hopkins Out patient Center. Their scans were analyzed by two otolaryngologists and three neuroradiologists by using a semiobjective rating system of the size and opacity of 36 anatomic areas. Patients estimated their own l eft and right sense of smell as excellent, diminished, or absent. Resu lts of the data are as follows: (1) There is no correlation between sm ell ability and size of the nasal and sinus structures. This indicates that there is no gross effect of the bulging of sinuses into the nasa l airway; (2) As a rule, opacity of only left-sided anatomic structure s was correlated with both left and right sense of smell (p < 0.01). T his suggests that our subjects were using their left smell receptors p referentially, to the exclusion of and in place of the right smell rec eptors; and (3) Total, not partial, opacity of the left olfactory clef t, frontal recess, or ethmoidal infundibulum was correlated with decre ased sense of smell. This suggests that these anterior structures in t he region of the olfactory cleft do affect airflow, but complete obstr uction of these spaces is needed. Possible explanations for the effect of opacified sinuses on the sense of smell include (1) The presence o f fluid or thickened mucosa in the sinuses may interfere with perceive d olfactory ability by changing nasal airflow patterns or odorant acce ss to receptors; (2) There may be olfactory receptors inside the sinus es; and (3) There may be a relation between the trigeminal receptors i n the sinuses and the olfactory system.