Contribution of Ultrasound Strain Elastography to the Differentiation of Benign and Malignant Thyroid Lesions: Randomized Controlled Study

Abstract

INTRODUCTION: We aimed to investigate the contribution of strain elastosonography to the differentiation of benign and malignant thyroid nodules. METHODS: The retrospective study included 135 patients who were detected with thyroid nodules on ultrasonography and then underwent fine-needle aspiration biopsy (FNAB). Semi-quantitative strain elastographic evaluation was performed and mean strain ratio was calculated for each nodule. The elastograms were classified using the Tsukuba five-pattern visual scoring system. Accordingly, the lesions with scores 1 and 2 were accepted as soft nodules (benign), score 3 as moderately hard nodules, and scores 4 and 5 as hard nodules (malignant). The nodules were divided as benign and malignant depending on the histopathological results. The FNAB results were compared with elasticity scores. RESULTS: The patients included 18 (13.3%) men and 117 (86.7%) women. Of the 135 lesions, 113 (83.7%) were benign and 22 (16.3%) were malignant. Strain ratio value was statistically higher in malignant lesions compared to benign lesions (p<0.01). When compared with the histopathological results, elastosonography scoring had a sensitivity of 81.8%, specificity of 89.4%, positive predictive value (PPV) of 96.2%, and negative predictive value (NPV) of 64.7%. However, compared with the strain ratio values, elastosonography scoring had a sensitivity of 77.3%, specificity of 87.6%, PPV of 95.2%, and NPV of 54.8% at a cutoff point of 4.850. DISCUSSION AND CONCLUSION: Elastosonography is highly effective in the differentiation of benign and malignant lesions.

Keywords

• ultrasound elastography
• strain elastography
• thyroid nodule