Comparison of CT and MRI in the detection of primary tumor extension of nasopharyngeal carcinoma: analysis of 283 cases

Objective To investigate the ability of computerized tomography(CT) versus magnetic resonance imaging(MRI) in detecting the extension of primary tumor of nasopharyngeal carcinoma(NPC).Methods Two hundred and eighty-three cases of primary NPC,histologically diagnosed and received enhanced spiral CT and MRI scans of nasopharynx were enrolled in this study.CT and MR images were analyzed by two radiologists in consensus.Chi-square test was used to compare the difference in detecting the involvement of each local site of NPC by method of CT and MRI.Results MRI appeared to be superior to CT in the detection of primary tumor extension to soft tissue of extra-nasopharynx cavity(95.1% vs(90.5%),P=0.035),retropharyngeal lymphadenopathy(74.6% vs 65.0%,P=0.013),bone invasion(44.2% vs 29.0%,P0.001),foramen in the skull base(39.6% vs 18.7%,P0.001) and cavernous sinus or intracranial infiltration((17.3%) vs 5.7%,P0.001),respectively.Conclusion Comparing with contrast-enhanced spiral CT,MRI has remarkable advantage in detecting of invasion of soft tissue of extra-nasopharyngx cavity,base of skull or foramen in it,cavernous sinus or intracranial,and retropharyngeal lymphoadenopathy of NPC.