RESUMO
Objective:To explore the value of the elasticity contrast index (ECI) in differential diagnosis of thyroid nodules, and contrast the effect of 4 different methods on measuring ECI.Methods:A total of 122 patients with 131 thyroid nodules in Binzhou Medical University Hospital from May 2018 to May 2019 were enrolled, and elastography was performed in 4 different ways such as in axial plane for internal (AI), axial plane for periintranodular (AP), longitudinal plane for internal (LI) and longitudinal plane for periintranodular (LP). The cut-off values for predicting malignant nodules in 4 different ways were determined separately using receiver operating characteristic (ROC) curve analysis.Results:There were 54 benign and 77 malignant ones in 131 nodules. The ECI in AI, AP, LI and LP in benign thyroid nodules was significantly lower than that in malignant ones: 2.10 (1.48, 2.34) vs. 3.07 (2.73, 3.87), 1.91 (1.64, 2.18) vs. 2.62 (2.24, 3.07), 2.19 (1.59, 2.39) vs. 3.00 (2.72, 3.63) and 1.89 (1.71, 2.16) vs. 2.66 (2.21, 3.10), and there was statistical difference ( P<0.05). Among the 4 different ways, the largest area under curve was achieved in AI with 0.925, and the corresponding optimal diagnostic threshold was 2.43 (with 90.9% sensitivity, 87.0% specificity, 88.5% accuracy, 89.7% positive predictive value and 86.8% negative predictive value). Conclusions:ECI is helpful for conventional ultrasound to diagnose thyroid nodules as malignant or benign. The best value is obtained in AI.