Differential Diagnosis Of Thyroid TI-RADS 4 Nodules By Virtual Touch Tissue Imaging

Objectives—To evaluate the additional value on Virtual Touch tissue imaging for diagnosis of thyroid TI-RADS 4 nodules.Methods—From October 2017 to January 2018,134 consecutive patients with 144 histologically proven thyroid nodules were enrolled in this retrospective study,these patients are prepared for ultrasound-guided fine needle aspiration biopsy.We choosed 9L4 linear array probe for Virtual Touch tissue imaging.The conventional ultrasound features of the nodules were recorded(location,maximum diameter,aspect ratio,border,edge,echo,halo,calcification,blood flow).Virtual Touch tissue imaging and area ratio measurements were performed for each nodule.The area ratio was defined as the area of the nodule on VTI divided by the area on B-mode sonography.Nodule stiffness on VTI was graded fromⅠ(soft)toⅥ(hard).Receiver operating characteristic curve analyses of VTI,area ratio,and the combination of VTI and area ratio were performed.The sensitivity,specificity,accuracy,positive predictive value(PPV),negative predictive value(NPV),and Youden index were also evaluated.Results—By receiver operating characteristic curve analyses,the cutoff values were VTI grade Ⅳ and area ratio of 1.22,respectively.Nodules with VTI grade Ⅳ or higher or area ratio of 1.22 or higher were more likely to be malignant.The sensitivity,specificity,accuracy,PPV,NPV,and Youden index were 83.5%,90.2%,87.5%,86.7%,88.1%,and 0.741(P<0.01)for VTI and 79.0%,80.5%,79.9%,75.3%,83.5%,and 0.495(P<0.05)for area ratio.However,when using the criterion of VTI grade IV or higher and area ratio of 1.22 or higher as a combination,the sensitivity,specificity,accuracy,PPV,NPV,and Youden index increased to 82.3%,92.7%,88.2%,89.5%,87.4%,and 0.749(P<0.05).Conclusions—The diagnostic performance of VTI grading and the area ratio for differentiation between benign and malignant thyroid nodules is equivalent.The performance is further improved with a combination of VTI grading and area ratio analysis.