Evaluation of CT Perfusion in the Diagnosis of Parotid Gland Mass

Purpose To explore the value of spiral CT perfusion imaging in differentiating benign and malignant parotid masses.Materials and Methods 47 patients with 50 parotid masses were enrolled including 25 cases with benign tumors(27 masses),8 cases with malignant tumors and 14 cases of inflammation(15 masses).All the masses were confirmed histopathologically and examined by CT perfusion imaging before surgery.CT perfusion parameters including blood flow(BF),blood volume(BV),mean transmit time(MTT) and permeability surface(PS),peck height(PH),time to peak(TTP) and time density curve(TDC) were evaluated.Wilcoxon sign sum test,a nonparametric test for paired data was used to determine the statistical differences of parameters between benign and malignant tumors.Results In benign tumors,BF,BV,PH were lower than those in malignant tumors(P 0.05 or P0.01) while TTP was higher than that in malignant tumors(P0.01);MTT and PS had no statis-tical difference compared with those in malignant tumors(P 0.05).The BV of inflammatory masses was lower than that in malignant tumors(P 0.01),and TTP was higher than that in malignant tumors(P0.05).The TDC shape of Warthin's tumor was different from that of other benign and malignant tumors.Conclusion The parameters of CT perfusion such as BF,BV,PH and TTP,were valuable in distinguishing benign from malignant masses in the parotid glands.