Comparative Study On The Value Dual-Energy CT And Ultrasound In Differentiating Benign From Malignant Thyroid Nodules

Objective:Through the observation and analysis of dual-energy CT data and ultrasound sonograms of thyroid nodules,and using pathological results as the gold standard,to explore the application value of dual-energy CT to distinguish benign and malignant thyroid nodules,and compared with ultrasound results.Methods:In this study,patients with thyroid nodules underwent ultrasound examination in our hospital.Under the premise of no contraindications,dual-energy CT enhanced examination was performed.All nodules were confirmed by pathology.A total of 57 nodules from 33patients were selected as the research subjects.The nodules were divided into benign groups（a total of 33）and malignant groups（a total of 24）based on pathological results.The GSI viewer software was used to analyze the two groups of thyroid nodules.The morphological characteristics of thyroid nodules were observed on the best single-energy image,and the morphology,borders,and presence or absence of micromicrocalcification were recorded.Phase,arterial phase,intravenous phase iodine concentration（IC）,normalized iodine concentration（NIC）,slope of spectral HU cure(λ_HU),water concentration（WC）and calcium concentration（CC）.Observe and analyze the ultrasound images of thyroid nodules in two groups,and record the morphology,borders,micromicrocalcification and blood flow signals of the nodules.Perform independent sample t test or nonparametric test on energy spectrum data,and use chi-square test（cell expected value≥5）or Fisher’s exact probability method（cell expected value<5）for energy spectrum morphological feature data.The data were analyzed using multi-factor logistic regression,using chi-square test（cell expected value≥5）or Fisher’s exact probability method（cell expected value<5）.And draw the receiver operating characteristic（ROC）curve,and determine its diagnostic efficacy by Area under ROC curve（AUC）.Results:A total of 57 thyroid nodules were included in this study,including 33 benign nodules and 24 malignant nodules.Analysis of morphological features of thyroid nodules by dual-energy CT.In the benign group,there were 28 regular morphologies,16 with clear borders,and 26without microcalcification.In the malignant group,there were 12 with irregular shapes,21 with unclear borders,and 12 with microcalcifications.The difference in morphological characteristics between the two groups was statistically significant（P<0.05）.The sensitivity of dual-energy CT to diagnose malignant nodules based on irregular morphology and unclear boundaries is 50%,87.5%,specificity is 84.8%,48.5%,the area under the ROC curve is 0.674,0.680,P<0.05,It shows that irregular morphology and unclear borders have certain diagnostic significance for malignant nodules,and the area under the ROC curve of nodules with calcified lesions shows no statistical significance in its diagnostic efficacy（P>0.05）.The iodine concentration（IC）,the slope of spectral HU cure(λ_HU)and the calcium concentration（CC）of the thyroid nodule in the benign group were 6.36（3.71,11.99）×100 ug/cm³,0.75（0.44,1.42）,8.19（5.23,16.75）mg/cm³,respectively,in the malignant group,3.26（1.12,4.98）×100 ug/cm³,0.36（0.12,0.59）,4.59（1.43,6.85）mg/cm³,the difference between the two groups was statistically significant（P<0.05）.The best diagnostic thresholds for iodine concentration（IC）,calcium concentration（CC）,and slope of spectral HU cure(λ_HU)for malignant thyroid nodules during plain scan are 5.4×100 ug/cm³,7.7mg/cm³,and 0.636,respectively.It is 60.6%,57.6%,57.6%,and the specificity is 87.5%,87.5%,87.5%.There was no significant difference in other energy spectrum parameters（P>0.05）.The morphology,boundary,and the presence or absence of microcalcification of the thyroid nodules in the ultrasound image were statistically significant between the benign and malignant groups（P<0.05）.Irregular morphology,indistinct boundaries,and microcalcification were used as the diagnostic criteria.The sensitivity of malignant nodules was66.7%,66.7%,and 69.7%,the specificity was 87.9%,75.8%,and 75.0%,and the area under the curve was 0.773,0.712,and 0.723,respectively.There was no significant difference between the benign and malignant groups in the presence or absence of blood flow signals in the thyroid nodules on the ultrasound sonogram（P>0.05）.In the comparative analysis of dual-energy CT and ultrasound,the AUC of malignant nodules diagnosed by ultrasound is higher than the iodine concentration,calcium concentration,and slope of the energy spectrum curve in the CT scan period;the iodine concentration,calcium concentration,and energy spectrum in the CT scan period The optimal diagnostic threshold for the slope of the curve is not statistically significant for the misdiagnosed nodules of ultrasound（P>0.05）.However,for the two malignant nodules misdiagnosed by ultrasound,the iodine,calcium,and The best diagnostic thresholds for the slope of the spectral curve are all diagnosed as malignant;the AUC of the calcium concentration in the CT scan period for the diagnosis of malignant thyroid nodules is higher than that in ultrasound,but its sensitivity is lower than that of ultrasound;the calcium in the CT scan period The optimal diagnostic threshold of concentration was used to evaluate thyroid nodules with no microcalcification on ultrasound.There was no statistically significant difference in the diagnosis results（P>0.05）,but malignant nodules evaluated by calcium concentration in the CT scan of the energy spectrum were in the malignant group The proportion is large.Conclusion:Dual-energy CT and ultrasound have certain value in the differential diagnosis of benign and malignant thyroid nodules.dual-energy CT morphological characteristics,flat scan iodine concentration（IC）,flat scan phase calcium concentration（CC）and flat scan phase spectrum curve slope(λ_HU)are significantly different between benign and malignant thyroid nodules,which helps Improve the accuracy of identification.In the comparative analysis of dual-energy CT and ultrasound,the AUC of malignant nodules diagnosed by ultrasound is higher than the iodine concentration,calcium concentration,and slope of the energy spectrum curve during the plain scan of the dual-energy CT;the iodine concentration,calcium concentration,and energy spectrum curve during the plain scan of the dual-energy CT The optimal diagnostic threshold of the slope has a certain hint for the diagnosis of misdiagnosed nodules by ultrasound;the AUC of calcium concentration in the CT scan of malignant thyroid nodules during the plain scan is higher than the microcalcification of ultrasound,but its sensitivity is lower than that of ultrasound;the energy spectrum During the CT scan,the calcium concentration has a certain hint effect on the nodules with no microcalcification.Therefore,based on the ultrasound examination of thyroid nodules,dual-energy CT can provide some quantitative parameters in addition to the characteristics of ultrasound sonograms,which has certain guiding significance for the differentiation of benign and malignant thyroid nodules,thereby further providing the choice of clinical treatment methods Real and objective imaging basis.