RESUMEN
Objective:To explore the reason why the CT manifestation of the patients with chronic nasosinusitis is negative.Method:To analyze the clinical and CT manifestation of the patients with chronic sinusitis having a negative CT manifestation.Result:Pathological changes were found in all 8 patients during the course of endoscopic sinus surgery, such as pus storing in the sinus cavity, mucous swelling polypoidly, small polyps formation and so on. Conclusion:The reasons that the patients with chronic sinusitis having a negative CT manifestation are, ①CT scan can only give a static one-off image, ② partial volume effect,③ maybe result from the location of CT scan and the resolving power of tomograph,④ maybe attribute to the pathological classify of chronic sinusitis.