The Value Of Spectral CT In Differentiating Common Parotid Benign Tumor

Purpose:To explore the value of spectral CT in diagnosis and differential diagnosis of parotid benign tumor.Methods:Medical records of 50 patients with benign parotid tumor confirmed by pathological results on biopsy samples were analyzed respectively,which included 22 cases of pleomorphic adenoma,20 cases of adenolymphoma,and eight cases of basal cell adenoma.All the cases were divided into three groups according to histological types.All patients underwent enhanced CT scanning with spectral CT.The standardized effective atomic number(Z_eff-s),normalized iodine concentration?NIC?,normalized water concentration?NWC?,slope of spectral HU curve(?_HU),and normalized slope of spectral HU curve(N?_HU)were measured and calculated based on the spectral CT data in both arterial and venous phases respectively,and the statistical analysis of them were performed by using SPSS20.0 software.The diagnostic efficiency of the spectral CT to differentiate parotid benign tumors was evaluated by the receiver operating characteristic curve.The value of statistically significant difference was set at P<0.05.Results:In arterial phase,the NIC,?_HU,and N?_HUU of the parotid benign tumors in descending order were:basal cell adenoma,adenolymphoma,pleomorphic adenoma,and the Z_eff-sff-s were:adenolymphoma,basal cell adenoma,pleomorphic adenoma,while in venous phase,the NIC,Z_eff-s,?_HU,and N?_HUU in descending order were:basal cell adenoma,pleomorphic adenoma,adenolymphoma,and the differences of NIC,?_HU,N?_HU,and Z_eff-sff-s in arterial phase and NIC,?_HUU in venous phase were statistically significant in three groups?P<0.05?,while there were no significant differences of all the other parameters?P>0.05?.When compared in two groups,the NIC,?_HU,and N?_HUU in arterial phase of pleomorphic adenoma compared with that of basal cell adenoma and adenolymphoma respectively,the differences were statistically significant?P<0.05?,the difference of Z_eff-sff-s between pleomorphic adenoma and adenolymphoma was statistically significant.In venous phase,the difference of NIC between adenolymphoma and basal cell adenoma was statistically significant,and when the?_HUU of adenolymphoma compared with pleomorphic adenoma and basal cell adenoma respectively,the differences were statistically significant?P<0.05?.Receiver operating characteristic curve analysis was performed on the parameters,it showed that the NIC,Z_eff-s,?_HU,and N?_HUU in arterial phase were helpful in diagnosing parotid adenolymphoma,especially NIC in arterial phase,while NIC and?_HUU in venous phase were helpful in diagnosing basal cell adenoma and especially NIC in venous phase,but spectral CT parameters showed no specificity in diagnosing pleomorphic adenoma.Conclusion:Quantitative parameters of enhanced Spectral CT may be helpful for the diagnosis and differential diagnosis of common benign parotid tumors.