Abstract: Objective To study the nuclear magnetic resonance image feature for involvement of paranasal sinuses in patients with nasopharyngeal carcinoma.Methods The MRI of 56 patients with NPC and paranasal sinuses infringed were evaluated between December 2003 and August 2004.Results Among them, 56(100%)showed breakage in the wall of paranasa sinuses, 29(51.8%)had thick mucous membrane in sinuses, 36(64.3%)showed tumour invasion sinuses, 55(98.2%)connected primary carcinoma with the lesion, and 14(25%)stored up fluid in sinuses.On MRI scan technique, the positive ratio of diagnoses were 66.1%, 76.8% and 98.2% respectively(P＜0.000)in the arial section, coronal section and sagittal section.And nearly 60% in the T1W1 and T2W1, but 100% in strengthen scan.Conclusions The finding of sinuses wall breakage;thick mucous membrane in sinuses;tumour invasion cavity connective mass, and same enhancement signal in MR image may indicate the paranasal sinuses involved by primary tumour.The sagittal section and enhanced MRI scan are helpful to diagnose.

Key words: Nasopharyngeal carcinoma, Paranasal sinuses, Nuclear magnetic resonance