Purpose: Shear-wave elastography (SWE) uses ultrasound to estimate the stiffness of tissues by measuring the degree of distortion and produces real-time quantitative colour-coded map of local tissue elasticity. The aim of the study was to analyze and compare SWE features of normal thyroid gland, and of benign and malignant thyroid
nodules.
Methods and Materials: Aixplorer Supersonic scanner with high-frequency transducer was used and B-mode and SWE were performed in 76 patients. 21 had normal thyroid gland on B-mode US, 5 had diffuse thyroid disease (4 Hashimoto and 1 Graves disease) and 50 had nodules. 38 patients had nodular goiter (uninodal or multimodal), 4 had thyroid adenomas, and 8 had cancer (7 papillary and 1 follicular). The colour scale indicated tissue elasticity in kilopascals (kPa). Maximum, minimum and mean kPa
E-values were recorded in each lesion and surrounding tissues.
Results: In normal thyroid gland E-values ranged from 6.2-48 kPa (mean 21), and blue color was dominant. In diffuse thyroid desease blue color was also dominant, with E-values in the range of 13.3-30.2 (mean 23) kPa.
Malignant tumors were significantly stiffer than benign nodules. Malignant nodules had E-values between 25.1-279.7 (mean 155) kPa, and were inhomogeneous, with dominant or significant read areas. Benign nodules had significantly lower E-values in the range of 6.9-153.7 (mean 62)
kPa.
Conclusions: Although the number of patients is small, malignant lesions have significantly lower elasticity and higher stiffness than benign lesions. Sonoelastography may be additional method to B-mode US and color Doppler in evaluating which thyroid nodule should undergo US-guided fine-needle
aspiration.
