Role of Ultrasound Elastography for Predicting Malignancy in Suspicious Thyroid Nodules: A Prospective Study

Abstract

Background: Accurate preoperative differentiation between benign and malignant thyroid nodules remains challenging, particularly in patients with indeterminate fine-needle aspiration cytology (FNAC). Ultrasound elastography (USE) has emerged as a promising, non-invasive diagnostic modality for assessing tissue stiffness and predicting malignancy. This prospective study evaluated the diagnostic performance of qualitative and semiquantitative ultrasound elastography in solitary thyroid nodules and assessed the feasibility of surgeon-performed elastography.

Methods: A prospective study was conducted on 135 patients with solitary thyroid nodules (1–5 cm) who underwent thyroid surgery. All patients underwent conventional ultrasonography with American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS), qualitative elastography using the Asteria colorimetric score, semiquantitative elastography using strain ratio, FNAC, and histopathological examination, which served as the reference standard. Diagnostic performance of individual and combined elastography parameters was analyzed.

Results: Histopathology confirmed malignancy in 38 (28.1%) and benign disease in 97 (71.9%) patients. The incidence of malignancy increased progressively with higher colorimetric scores and strain ratios. Qualitative elastography demonstrated a sensitivity of 80.4%, specificity of 68.0%, and accuracy of 68.6%, whereas semiquantitative elastography achieved a sensitivity of 78.9%, specificity of 84.5%, and accuracy of 84.2%. Combining both elastography techniques improved diagnostic performance, yielding a sensitivity of 73.3%, specificity of 85.5%, negative predictive value of 89.2%, and overall accuracy of 84.8%. Surgeon-performed elastography demonstrated diagnostic performance comparable to radiologist-performed examinations.

Conclusion: Ultrasound elastography is a valuable adjunctive tool for predicting malignancy in solitary thyroid nodules. Combined qualitative and semiquantitative elastography provides high diagnostic accuracy and negative predictive value, potentially reducing unnecessary diagnostic thyroid surgery, particularly in patients with indeterminate cytology.