Abstract: Objective To investigate the characteristics of sinus computed tomography in patients with eosinophil chronic nasosinusitis(ECRS)and non-eosinophil chronic nasosinusitis(NECRS). Methods A total of 1010 patients with chronic rhinosinusitis(CRS)were enrolled and divided into the ECRS(n=458)and NECRS(n=552)groups according to the eosinophil to inflammatory cell count ratio(Eos%)in tissue, with a cut off limit of Eos%≥10%. The Lund Mackay score, sinus lesion rate, and sinus lesion type were analyzed between the two groups. The Lund Mackay score and sinus lesion type were analyzed between the ECRS and NECRS groups at different ages, and the value of ethmoid sinus to maxillary sinus score(E/M)in predicting ECRS was also investigated. Results In the ECRS group, the ethmoid sinus, frontal sinus, sphenoid sinus, ostiomeatal complex(OMC)and total scores were higher(P<0.01), while the maxillary sinus scores were lower than those in the NECRS group(P<0.01). The lesion rates of anterior ethmoid sinus, posterior ethmoid sinus, sphenoid sinus, and frontal sinus in the ECRS group were also higher than those in the NECRS group. There was no significant difference in Lund Mackay scores between the ECRS(P=0.786)and NECRS(P=0.634)groups at different ages. The proportions of full set of sinusitis, ethmoid sinus lesion dominant, and non-ethmoid sinus lesion dominant CRS types in ECRS and NECRS groups were 39.08%, 37.24%, 23.58% and 26.45%, 8.88%, 64.67%, respectively. In addition, with the increase of age, the proportion of full set of sinusitis in ECRS in adult patients increased gradually(P=0.04). When E/M>2 was used as the cut-off value, the AUC for predicting ECRS in all patients was 0.67, while that in patients without a full set of sinusitis was 0.75. Conclusions The ethmoid sinus, frontal sinus, and sphenoid sinus lesions in ECRS are more severe than those in NECRS, while the maxillary sinus lesions are less severe. Furthermore, the ethmoid sinus, sphenoid sinus, and frontal sinus are more easily involved in ECRS than in NECRS. ECRS comprises mainly ethmoid sinus lesions with full set of sinusitis, while NECRS comprises mainly non-ethmoid sinus lesions with full set of sinusitis. The incidence of full set of sinusitis in adult ECRS patients increases with age. E/M > 2 has limited predictive value for ECRS in patients with full set of sinusitis.

Key words: Eosinophils, Sinusitis, Maxillary sinus, Ethmoid sinus, Sphenoid sinus, Frontal sinus, Computer tomography