A Preliminary Study On Differential Diagnosis Of Benign And Malignant Thyroid Nodules By The Third-generation Dual-source CT Iodine Map With Low Kv

Objective:To assess the feasibility of the third-generation dual-source CT with low kv applied in diagnosis of thyroid nodule.Methods:40 patients in the first affiliated hospital with thyroid nodules were randomly divided into two groups.All cases underwent the third-generation dual-source dual-energy CT plain scanning.Group A(standard dose protocol 90/Sn150 kv,n=20);group B(low-dose protocol 70/Sn150 kv,n=20);Both of two groups take autoCare dose 4D.Radiation dose,the signal noise ratio(SNR),SD and image quality were compared and analyzed statistically.Results:Image qualities of two groups were not significantly different(P> 0.05).The mean effective radiation dose in 90 kv group was higher than that oflow-dose groups(P<0.05).It showed no statistical significance of mean SNR between two groups(P>0.05).There was no statistic significance on SD of two groups(P> 0.05).Conclusion:The third-generation dual-source CT With low kv on thyroid,not only ensure image quality,but also reduce the radiation dose;it is hopefully used in the diagnosing thyroid nodule,and worthy of further application.Objective:To investigate the clinical application of iodine concentration using the Simens third generation dual-source dual energy CT in distinguishing malignant from benign thyroid nodules.Methods:64 patients from the first affiliated hospital with thyroid nodules underwent third-generation dual source dual energy CT scanning.Some cases with nodular goiter were proven by follow-up for 6 months.The other were confirmed by surgery or puncture pathology gold standard.The mean iodine concentrations during plain scan(PS),arterial phase(AP)and venous phase(VP)in the lesion(ICLes),the normal thyroid parenchyma(ICThy),and the carotid artery(ICCar)were measured from iodine map.The normalized iodine concentration ratio(NIC)were calculated.The two-sample t test was performed to compare quantitative parameters between the benign and malignant nodules,between left and right thyroid lobe.ROC curve with statistically different parameters between benign and malignant nodules was used to analyze the diagnostic sensitivity and specificity.Results:Of the 64 patients,40 were benign(62.5%),including 15 adenomas(37.5%)and 25 nodular goiter(62.5%);24 cases(37.5%)were malignant and all were papillary.During plain scanning,mean ICLes of benign and malignant nodules were1.1175±0.3961mg/ml and 0.7042±0.3394mg/ml,.ICLes of benign noduleswas higher than malignant nodules.There was statistic difference in ICThy and ICles of benign nodules and malignant nodules.Mean ICThy between benign and malignant nodules were1.6225±0.6739?(1.6208±0.6903)mg/ml respectively.Mean NIC of normal thyroid in AP between benign nodules and malignant nodules were 0.5180±0.0872 and0.5250±0.0797;while in VP 0.9712±0.2166 and 0.9496±0.1496.NIC between malignant and benign nodules were 0.4025±0.0984?0.3825±0.0659,showing no statistic difference in AP.During VP,mean NIC of benign and malignant nodules were0.7577±0.2444?0.5754±0.2000,NIC of benign nodules were higher than benign nodules(P< 0.05).When using ICLes during PS and NIC during VP value of 0.85 and 0.59 to differentiate malignant thyroid nodules from benign nodules,the sensitivity and the specificity were0.725,0.775 and 0.608,0.583 respectively.Conclusion:We are able to measure the iodine concentrations of normal thyroid tissue,benign and malignant thyroid nodules by using the third-generation dual-source CT iodine image.It can help differentiate benign and malignant thyroid nodules.