The Value Of Diffusion-Weighted MR Imaging And DCE-MRI In Distinguishing Benign And Malignant Thyroid Nodules

PartⅠ The value of quantitative parameters of dual-energy CT iodine map in differentiating benign and malignant lesions of vocal cordObjective To analyze the characteristics of MR DWI in thyroid nodules and to explore the value of DWI in distinguishing benign and malignant thyroid nodulesMethods 38 patients with thyroid nodules underwent MR and DWI scans before surgery and compared postoperative pathological findings.Evaluate the image quality(SNR、CNR)of three different b-values(300,500,and 1000 s/mm2);The SNR and CNR of different b-value DWI images were analyzed by randomized block analysis of variance.Independent sample t-test is used to compare the ADC values and rADC values of the three groups of b-valued benign and malignant nodules,ROC and AUC were analyzed for diagnostic performance.The difference was statistically significant at P<0.05.compare the difference in ADC values of benign and malignant nodules to find the best b-value and threshold of ADC.Results 69 nodules were found in 38 patients,including 26 benign nodules(37.68%)and 43 malignant nodules(62.32%).The largest nodule is about 4.24cmx4.08cm,and the smallest one is about 0.8cmx0.8cm;among them,36 nodules(52.17%)on the left lobe,27 nodules(39.13%)on the right lobe,and 4 nodules(5.80%)in the isthmus.2 cases of multiple lesions(2.90%).Benign nodules include 21 nodular goiters(80.77%),34 adenomas(15.38%),1 eosinophilic adenoma(3.85%),and 31 malignant nodules,including thyroid papilla There were 39 cancers(90.70%),1 medullary carcinoma(2.33%),1 mixed cancer(medullary carcinoma+PTC)(2.33%),and 12 follicular carcinomas(4.65%).The SNR and CNR of the three groups of different b-value DWIs were statistically significant(P<0.05),and the image quality is best when the b value is 300 s/mm2.The ADC values of the three groups of thyroid benign and malignant nodules were statistically significant(P<0.05).The diagnostic efficiency was higher when b=300 s/mm2,it also leads the largest AUC,the optimal diagnostic threshold is 1.685×10-3 mm2/s with a sensitivity of 78.83%and pecificitys of 87.5%.Conclusion The magnetic resonance scan DWI image has high sensitivity and specificity for the diagnosis of malignant thyroid nodules.The ADC value is worth more when identifying the thyroid gland and malignant nodules when the b value is 300 s/mm2Part Ⅱ The value of Dynamic Contrast Enhanced Magnetic Resonance Imaging in the differential diagnosis of benign and malignant thyroid nodulesObjective To analyze the difference of TIC interval and related parameters between benign and malignant thyroid lesions,and to explore the value of DCE-MRI in distinguishing benign and malignant thyroid nodules.Methods 34 patients with thyroid nodules underwent routine MR and DCE-MRI scans before surgery.According to the ROI of the lesions,the TIC curve was generated,Tmax.,SIpre.SImax and SIend were recorded.calculated the maximum enhancement rate(Emax),the ascending slope of cruve(Slope)and the enhanced end-stage attenuation signal ratio(ERe/m);combined with postope-rative pathological results,compared the differences between the parameters of benign and malig-nant nodules.The measurement data were tested for normality or homogeneity of variance,the two-sample t-test was used for statistical analysis.If the data did not meet the positive distribution,the Wilcoxon test was used.P<0.05 was considered statistically significant..Results 69 nodules were found in 38 patients,including 26 benign nodules(37.68%)and 43 malignant nodules(62.32%),same as part Ⅰ.There were 20 cases with type Ⅰ TIC curve,33 cases with type Ⅱ curve,13 cases with type Ⅲ curve,and 3cases with IV type curve.All the benign lesions show type I curve(16/20);there are 32 malignant lesions and 1 benign lesion in the 33 type Ⅱ curve,13 malignant lesions and 1 benign lesion were found in 13 type Ⅲ curve,3 Case IV curves were found in benign lesions.There was a statistically significant difference in the final signal attenuation ratio(ERe/m)between benign and malignant lesions in the relevant parameters.When the ERe/m value was 0.414,it could provide an ideal diagnostic efficiency with a sensitivity of 85.0%and a specificity of 87.8%.Conclusion The semi-quantitative index of DCE-MRI has a good diagnostic efficacy for the identification of benign and malignant thyroid lesions;the dynamic enhancement TIC curve between benign and malignant thyroid nodules is significant and can be used as a reference.Part Ⅲ Combine DWI、DCE-MRI and TI-RADS for differential diagnosis of benign and malignant thyroid nodulesObjective Uniting DWI,DCE-MRI,ultrasonography for multiple scans of thyroid nodules,diagnostic parameters,establish a multimodal diagnostic model to improve the diagnostic efficacy of benign and malignant thyroid nodules.Methods Collect thyroid nodules that underwent at least one of DWI,DCE-MRI,and regular ultrasound,and have a total of 69 nodules with pathological results;organize the examination items and calculate the accuracy of each inspection item.Rate;comparing the pathological results,a diagnostic model was established using Logistic regression,and the diagnostic model was analyzed using the ROC curve.Compared with single MRI-DWI,MRI-DCE,ultrasonographic diagnosis accuracy and model diagnosis accuracy,compare the respective AUC size,which results in a higher diagnostic value.Results There were 26 benign nodules and 43 malignant nodules in 69 nodules.All of them underwent DWI、DCE-MRI and Ultrasound.Logistic regression was used to analyze all variables,and finally the significant correlation variables were found to be ADC values of b=300 s/mm2(P<0.001,OR=1,95%CI:0.0000,1.469),and the final signal attenuation ratio(ERe/)was enhanced.m)was a significant correlation factor(P=0.0012,OR=0.0000,95%Cl:0.0000,0.0013),ultrasound diagnosis(P<0.001,OR=1.4544,95%CI:0.0578,17.2977).The ADC value(b=300s/mm2)has an area under the ROC curve of 0.8577,a specificity of 83.33%,a sensitivity of 78.79%,and an accuracy of 80.39%.The area under the ERe/m ROC curve is 0.8004 and the specificity is 78.95%.The sensitivity is 89.66%and the accuracy is 85.42.The area under the ROC curve of conventional ultrasonography is 0.6800,the specificity is 86.00%,the sensitivity is 50.00%,and the accuracy is 72.85%.Finally,the three variables are used to establish the Nomogram model.The model ROC diagnosis AUC was 0.9378,the specificity was 86.67%,the sensitivity was 78.95%,and the diagnostic accuracy was 86.67%.Conclusion DWI,DCE-MRI,ultrasonography three test parameters and diagnostic results to establish a diagnostic model for the differential diagnosis of benign and malignant thyroid nodules has a good diagnostic value;patients with DWI,DCE-MRI,ultrasound than single imaging can be Clinical treatment provides more information;DWI,DCE-MRI is expected to be the preferred method for differential diagnosis of benign and malignant thyroid nodules.