RESUMO
Objective To evaluate the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)for the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.Methods Thirty-one pa-tients with histopathologically proved adenoid cystic carcinoma and pleomorphic adenoma were examined with DCE-MRI,in which 10 cases were benign and 21 cases were malignant.The data of the conventional 3.0T DCE-MRI were improved by the 3D fast spoiled gradient-echo sequence (FSPGR)method.Z-test was performed on the quantitative parameters for benign and malignant le-sions,including volume transfer constant (Ktrans ),rate constant (Kep )and extravascular extracellular space fraction (Ve ).The re-ceiver operating characteristic (ROC)curves were plotted to investigate the diagnosis.Results The mean Ktranss of the adenoid cystic carcinoma group and pleomorphic adenoma group were (0.266 ± 0.103 )min-1 and (0.1 55 ± 0.080)min-1 respectively,and the difference between them were statistically significant (Z =-2.699,P 0.05).The areas under the ROC curves of the Ktrans and kep were 0.813 and 0.763 respectively.Choosing the optimal diagnostic cut-off points corresponding to the maximum Youden indexes 0.173 min-1 and 0.818 min-1 ,the sensitivities of Ktrans and kep for identifying the adenoid cystic carcinoma and pleomorphic adenoma were 90.9% and 81.8%,and the specificities were 77.8% and 66.7%.Ktrans was of the highest sensitivity and specificity for the identification of the adenoid cystic carcinoma and pleomorphic adenoma.Conclu-sion The dynamic contrast-enhanced parameter Ktrans plays a certain role in the differential diagnosis of the adenoid cystic carcinoma and pleomorphic adenoma of the head and neck.