The Value Of ADC In MR-DWI In Differentiating Benign And Malignant Thyroid Nodules And B Value Were Selected

PartⅠThe value of ADC value of MR-DWI in differentiating benign and malignant thyroid nodulesObjective:to evaluate the apparent diffusion coefficient(ADC)value of magnetic resonance(MRI)diffusion weighted imaging(DWI)in the differentiation of benign and malignant thyroid nodules.Methods:Forty patients with thyroid nodules underwent MRI that included conventional imaging and DWI imaging before surgery,and the diffusion gradient factor b values chosen 0,300,500,800 and 1000s/mm~2.Patients were divided into benign thyroid nodules group and malignant thyroid nodules group according to the pathological results after surgery.The differences of ADC values between benign thyroid nodules and malignant thyroid nodules under the same b value were compared,and receiver operating characteristic(ROC)curves of ADC values under different b values were plotted.The ADC values of benign and malignant thyroid nodules at the same b value were analyzed with SPSS 21.0 software,and the ROC curve was drawn.Results:1.Under the same b value,the ADC value of thyroid malignant nodules is lower than that of benign nodules(P<0.001);2.When the b values were 300,500,800,and 1000s/mm~2,the area under the ROC curve was 0.937,0.902,0.908,and 0.890,respectively(all>0.80).Conclusion:The apparent diffusion coefficient of diffusion weighted magnetic resonance imaging is of high value in differentiating benign and malignant thyroid nodules.Part II Evaluation of the value of b in MR-DWI in the identification of benign and malignant thyroid nodulesObjective:To investigate the value of differential diffusion-sensitive factor(b-value)magnetic resonance imaging(MRI)diffusion weighted imaging(DWI)in the differential diagnosis of benign and malignant thyroid nodules and the selection of optimal b-value.Methods:Forty patients with thyroid nodules and 23 normal volunteers were subjected to conventional magnetic resonance imaging and DWI imaging using the Philips Achieve 3.0T scanner in the Netherlands.The b values were selected from 0,300,500,800,and 1000 s/mm~2,respectively.The maximum left and right diameters of thyroid and thyroid lesions on DWI and T2WI images at b value were obtained from five groups and statistically analyzed.According to the postoperative pathological results of the patients,the thyroid nodules were divided into benign group and malignant group,and the receiver operating characteristic(ROC)curve of ADC value under different b values was plotted,and the area under the curve was statistically analyzed.Determine the b value that is optimal for the diagnosis.The data analysis is divided into two parts.The first part uses SPSS21.0software to statistically analyze the maximum left and right diameter data of normal thyroid and thyroid lesions on T2WI and DWI images under different b values.The second part uses different versions of MedCalc17.6.The area under the ROC curve of the ADC values of benign and malignant nodules of the thyroid gland was statistically analyzed.Result:1.The maximum transverse diameter of the thyroid gland on DWI image under the b value of 300,500,800,1000 s/mm~2 ang the T2WI image were statistically different(P<0.05).There was no statistical maximum transverse diameter of the DWI image between different b values(P>0.05);2.There was no significant difference in the maximum transverse diameter of the DWI images between the b-values of 800 and 1000s/mm~2(P>0.05),and There was a statistical difference between the maximum transverse diameter of the thyroid lesions on the T2WI images of the remaining DWI images under b values of 300,500,800,1000 s/mm~2(P<0.05).When the b value was 300 s/mm~2,the difference of the transverse diameter between the DWI and T2WI images was the smallest;3.There was no significant difference in the area under the ROC curve between the ADC values of benign and malignant nodules of different thyroid values(P>0.05).Conclusion:Combined with the imaging effect and diagnostic value,when the b value is 300 s/mm~2,the best effect on the benign and malignant nodules of the thyroid is identified.