Evaluation of the Perinodular Stiffness Potentially Predicts the Malignancy of Thyroid Nodules.

Abstract

To evaluate the surrounding tissue stiffness measured by sound touch elastography for differential diagnosis of thyroid nodules (TNs). Thirty-nine benign and 90 malignant TNs were included in this study. The conventional ultrasound features, the maximum Young modulus value of the stiffness of the TNs (recorded as E), and the stiffness of the 0.5-, 1.0-, 1.5-, and 2.0-mm perinodular regions of the TNs (recorded as Eshell0.5 , Eshell1.0 , Eshell1.5 , and Eshell2.0 , respectively) were prospectively analyzed and compared to histopathologic results. The abundance of collagen fibers at various widths in the perinodular regions of the TNs was evaluated by Masson staining and ImageJ software (National Institutes of Health, Bethesda, MD). The fibrous structures in the perinodular regions of the TNs were classified. The various Eshell values of malignant TNs were significantly higher than those of benign TNs (P < .001 for all). Eshell0.5 correlated highly with E in the malignant TNs and in all samples (r = 0.722 and 0.772; P < .001 for both). Eshell2 yielded the highest area under the receiving operating characteristic curve value (0.96) for the differential diagnosis of TNs. The abundance of collagen fibers in the 2-mm perinodular region of the TNs was closely correlated with Eshell2 in the malignant TNs and in all samples (r =0.729 and 0.867; P < .001). The Eshell2 values for different levels of disorder of the tissue surrounding TNs were significantly different (P < .01 for all). Perinodular stiffness measured by sound touch elastography improved the diagnostic accuracy in TNs.