[Significance of differential diagnosis for sinonasal mass by CT value].

To explore whether CT value is useful in identifying different disease in tumors of rhinosinus parenchyma.
 Methods: The data of preoperation noncontrast CT in 277 patients were retrospectively reviewed. The final diagnosis and classification were based on the result of surgical histopathological examination. The CT value range for different classification was calculated and was compared. All patients were re-diagnosed according to CT value range combined with pathological results by the same doctor team. The diagnosis rates according to CT value range were compared.
 Results: The CT value was (25.3±3.5) Hu in nasal polyp, (7.9±3.5) Hu in serous cyst, (42.2±4.7) Hu in mucocele, (40.7±5.3) Hu in papilloma, (112.3±10.9) Hu in fungus ball, (41.7±4.8) Hu in hemangioma, (51.2±9.9) Hu in malignant melanoma, and (47.1±9.9) Hu in squamous carcinoma. The CT value in nasal polyp is significantly higher than that in serous cyst, which was significantly lower than that in mucocele, papilloma, fungus ball, hemangioma, malignant melanoma and squamous carcinoma (all P<0.05); the CT value in serous cyst was significantly lower than that in other classification diseases (all P<0.05); the CT value in fungus ball was significantly higher than that in other classification diseases (all P<0.05); there was no significant difference in CT value among mucocele, papilloma, hemangioma, malignant melanoma, squamous carcinoma (all P﹥0.05). The diagnosis rate was elevated (from 71.1% to 92.4%) according to CT value range, with significant difference (χ2=42.150, P<0.01).
 Conclusion: CT value in nasal polyp, serous cyst, fungus ball is different from other diseases, and the 3 diseases can be distinguished only by CT value range; the CT value in mucocele, papilloma, hemangioma, malignant melanoma and squamous carcinoma is similar, and their differential diagnosis should combine with imaging data and other clinical characters. The diagnosis rates can be improved when the CT value range is taken into account.