Accuracy of the slope of energy spectrum CT curve and iodine concentration quantitative analysis in the differential diag-nosis of benign and malignant thyroid nodules

YAN Lihui; YAO Lizheng; LI Xin; WANG Shu; CHEN Fei

Abstract：Objective To explore the application value of slope of energy spectrum CT curve and iodine concentration quanti-tative analysis in the differential diagnosis of benign and malignant thyroid nodules.Methods 48 patients with thyroid nodules screened by ultrasound were selected as the study objects.Taking the results of pathological examination as basis, the patients were randomized into malignant group (n=21) and benign group (n=27);20 normal subjects without thyroid nodules who un-derwent neck examination in the same period were included in the normal group (n=20).Both of subjects in two groups under-went energy spectrum CT imaging ( GSI) monoenergetic mode scan and enhanced scan by using energy spectrum CT.Then, GSI Viewer software was used to calculate the iodine concentration and slope of energy spectrum curve.The calculated results were compared between the three groups of subjects;Based on the results of pathological examination, the accuracy of energy spectrum CT examination in differential diagnosis of benign and malignant thyroid nodules was analyzed.Results There were 26 cases with benign nodules and 19 cases with malignant ones correctly diagnosed by CT.The accuracy in differential diagnosis of benign and malignant thyroid nodules was 93.8%(45/48).The slop of energy spectrum curve and detection results of iodine concentrations during arterial and venous phase in the malignant group in different phases were significantly lower than those in the other two groups ( P <0.05).In plain scan phase, the iodine concentrations in benign and malignant group were lower than those in the normal group ( P <0.05) but there was no significant difference between the two groups ( P >0.05).Conclusion Energy spectrum CT in differential diagnosis of benign and malignant thyroid nodules is with high accuracy.In clinic, it can be used as a feasible imaging examination means in the diagnosis and treatment, providing basis for development of follow-up treatment regi-men.