Diagnostic Performance of Ultrasound Elastography in Differentiating Benign and Malignant Thyroid Nodules: A Prospective Cross-Sectional Study

Abstract

Background: Thyroid nodules are among the most common endocrine abnormalities encountered in clinical practice. Although most thyroid nodules are benign, accurate identification of malignant lesions remains crucial for appropriate management. Conventional ultrasonography is the primary imaging modality for thyroid nodule evaluation; however, overlap in imaging characteristics often limits diagnostic specificity. Ultrasound elastography has emerged as a valuable adjunctive technique that assesses tissue stiffness, potentially improving differentiation between benign and malignant thyroid nodules. Objective: To evaluate the diagnostic performance of ultrasound elastography in differentiating benign and malignant thyroid nodules using cytopathology and histopathology as reference standards. Methods: A prospective cross-sectional study was conducted involving 180 consecutive patients presenting with thyroid nodules. All participants underwent conventional ultrasound and strain elastography. Elastography scores were assigned using a five-point elasticity scoring system. Fine needle aspiration cytology (FNAC) and surgical histopathology were used as reference standards. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic accuracy, and receiver operating characteristic (ROC) analysis were performed. Results: Among 180 thyroid nodules evaluated, 48 (26.7%) were malignant and 132 (73.3%) were benign. Elastography scores 4–5 were significantly associated with malignancy (p<0.001). Ultrasound elastography demonstrated a sensitivity of 89.6%, specificity of 84.8%, PPV of 68.3%, NPV of 95.7%, and overall diagnostic accuracy of 86.1%. ROC analysis yielded an area under the curve (AUC) of 0.91 (95% CI: 0.86–0.96), indicating excellent discriminatory performance. Conclusion: Ultrasound elastography significantly improves differentiation between benign and malignant thyroid nodules and may reduce unnecessary invasive procedures. Incorporation of elastography into routine thyroid imaging protocols can enhance diagnostic confidence and optimise patient management.