Diagnostic accuracy of TI-RADS classification in differentiating benign and malignant thyroid nodules-a study from Southern Punjab, Pakistan

Background and Objective: Thyroid imaging reporting and data system (TI-RADS) is developed to determine the risk of malignancy in patients with thyroid nodules. The aim of this study was to determine the diagnostic accuracy of TI-RADS classification for diagnosing malignant thyroid nodules taking Fine needle aspiration cytology (FNAC) as a gold standard in the local population. Methods: In this cross-sectional validation study, 201 patients presenting with thyroid nodules at the Department of Radiology, Bakhtawar Amin Hospital Multan, Pakistan from July 2020 to December 2020 were included. In all patients, thyroid nodules were evaluated on grey scale (B-mode) modality. TI-RADS score was calculated for each patient. Patients with TI-RADS score 4 and 5 were labelled as having malignant nodules. After that FNAC samples were taken and sent for histopathologic evaluation of thyroid nodules. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TI-RADS taking FNAC as a gold standard were determined. Results: The mean age of the patients was 47.8 ± 4.5 years; there were 129 (67.2%) women and 72 (35.82%) men. There were 42 patients who tested true positive and 36 patients tested false positive and 12 patients were false negative and 111 patients true negative. The TIRADS sensitivity was 77.8%, specificity was 75.5%, PPV was 53.8%, and NPV 90.2%. the diagnostic accuracy was 76.1%. Conclusion: Differentiating benign thyroid nodules from malignant using the TI-RADS score has a high diagnostic accuracy. Our study results support the TIRADS as a first-line imaging evaluation for diagnosis of thyroid malignancy.