The Application Of Multimodal Ultrasonic Elastography In The Differential Diagnosis Of Thyroid Nodules

ObjectiveTo explore different characteristics of multimodal ultrasonic elastography and the clinical application value in the differential diagnosis of thyroid nodules.MethodsThe 14L5 line array probe of ACUSON HELX S2000 of color Doppler ultrasonic diagnostic apparatus was used to describe the 2D ultrasononic characteristics of 107 patients with 129 thyroid nodules. The multi-modes ultrasonic elastography including elastography imaging(EI),virtual touch tissue imaging(VTI),virtual touch tissue quantification(VTQ) and virtual touch tissue imaging quantification(VTIQ) were obtained by 9L4 line array probe. With pathological diagnosis as gold standard, the diagnostic value of the multi-modes ultrasonic elastography was analyzed by using related elastic image evaluation and elastic parameters measurement, which including EI scores,VTI scores,elastic strain ratio(SR),EI area ratio(AR1), VTI area ratio(AR2),average SWV of VTQ(Vm1), average SWV of VTIQ(Vm2), maximum velocity of VTIQ(Vmax2) and the subtraction of maximum and minimum velocity of VTIQ(Dswv). The results were statistically analyzed with P<0.05 indicating significant differences.Results1. All of 129 nodules were confirmed by surgical pathology. Among these, 93 thyroid nodules were malignant and 36 were benign. There existed significantly statistical differences between the malignant and benign nodules in the nine elastic parameters(all P<0.05).2. With pathological diagnosis as gold standard, ROC curves of all the nine elastic parameters were made, and AUC of qualitative parameters including EI scores and VTI score were 0.752 and 0.821, respectively. AUC of semi quantitative parameters including SR,AR1 and AR2 were 0.842, 0.795 and 0.787, respectively. AUC ofquantitative parameters including Vm1, Vmax2, Vm2 and Dswv were 0.774, 0.746,0.805 and 0.751, respectively. The maximum Youden index was chosen to determine the optimum thresholds of all the parameters in ROC analyses. Statistical analysis demonstrated a threshold value of 3 score for EI scores, 4 score for VTI score, 2.68 for SR, 1.30 for AR1, 1.40 for AR2, 2.47m/s for Vm1, 3.63m/s for Vmax2, 2.48m/s for Vm2, 2.48m/s for Vm2 and 1.45m/s for Dswv.3. All of the value of elastic parameters in papillary carcinoma group were significantly higher than that of goiter nodules group. Whereas only three parameters including EI scores,VTI scores and SR were statistical differences when compared papillary carcinoma with follicular adenoma, showing the former higher than the latter(P﹤0.05).4. In TI-RADS 4a-4b thyroid nodules,the diagnostic accuracy was improved for Vm2, SR value and VTI score in smaller nodules(< 1cm) compared to the diagnose of2 D ultrasonography, and there were significant differences of Vm2 diagnostic accuracy compared with SR, VTI score respectively(P<0.05). In biggerer nodules(>1cm), the diagnostic accuracy was improved by using EI score and VTI score.There was high specificity(100%) by using AR1, AR2 and Vm1 in bigger nodules. The Vmax2 also had a high specificity(100%) in both smaller and bigger nodules.5. Combined the size of nodules with elastic parameters, the binary logistic regression analysis showed the maximum diameter of nodules and SR were selected into the logistic regression equation of which the sensitivity, specificity and accuracy in predicting thyroid nodules were 82.3%, 78.5% and 79.8% respectively. AUC was 0.823 for this equational predicting value.Combined 2D ultrasonography with elastography,the binary logistic regression analysis showed the maximum diameter and echo of nodules, Vmax2 and Vm2 were selected into the logistic regression equation of which the sensitivity, specificity and accuracy in predicting thyroid nodules were 100%,70.7%and 91.5%, respectively. AUC was 0.927 for this equational predicting value.Conclusions1. There is a certain clinical value in differential diagnosis of benign and malignant thyroid nodules by using different ultrasound elastography due to it can reflect hardness and density of tissue. There was high diagnostic accuracy for Vm2, SR value and VTI score in smaller nodules. However, in bigger nodules, VTI score and EI score have high diagnostic accuracy ability. In addition, the diagnostic specificity were high for AR1, Vm1 and Vm2 in bigger nodules.2. Adjusting the SWV range of VTIQ can help find the hard points which would be contribute to find the cancer area of the papillary carcinoma and increase the diagnostic accuracy.3. Combining 2D ultrasonography with elastography after correctly read 2D ultrasound performance and choose appropriate ultrasonic elastic mode examination,the sensitivity, specificity and accuracy of thyroid nodules could be improved.