Role of Sonography in Characterization of Thyroid Nodules and Differentiation as Benign or Malignant

Abstract Background: Thyroid nodules are a common finding in clinical practice, increasingly detected due to the widespread use of high-resolution ultrasound. Although most nodules are benign, a significant minority may be malignant, necessitating a reliable triage strategy to determine which nodules require further intervention. The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TIRADS) offers a structured risk stratification system based on sonographic features. Objective: This study aims to evaluate the diagnostic performance of ultrasound-based TIRADS classification in distinguishing benign from malignant thyroid nodules. A conservative approach was adopted by classifying TIRADS III lesions as “suspicious,” in addition to the usual IV and V categories. This protocol was designed to maximize sensitivity, especially in a real-world setting with variable follow-up. Methods: This was a prospective observational study conducted in the Department of Radiodiagnosis, MGM Medical College, Kamothe, Navi Mumbai, between January and May 2025. In each patient, the most suspicious nodule (highest TIRADS score) was evaluated. Final diagnoses were based on histopathological results or CT imaging where pathology was unavailable. Statistical analysis was conducted to determine sensitivity and specificity.Results: Out of 30 patients, 13 were confirmed malignant and correctly classified as suspicious (TIRADS III–V), yielding a sensitivity of 100%. Seven nodules were falsely labeled suspicious but were benign on final diagnosis, resulting in a specificity of 58.82%. The negative predictive value was 100%, and there were no false negatives. Conclusion: Ultrasound using ACR TIRADS is a highly sensitive tool for evaluating thyroid nodules. Including all TIRADS III as suspicious improves malignancy detection and eliminates false negatives, albeit with a trade-off in specificity. This protocol is especially suited for conservative screening in resource-limited or high-risk patient populations.