Assessment of accuracy of thyroid imaging, reporting and data system for diagnosis of thyroid nodules.

Abstract

Summary Background: thyroid ultrasound is one of the most accepted and first investigation modality in assessing thyroid diseases. It is cheaply available, painless and is without any radiation risk. Particularly for patients with thyroid nodules management decisions depends highly on thyroid ultrasound and fine needle aspiration cytology results. Objectives: the aim of this study was to assess accuracy of thyroid imaging, reporting and data system for diagnosis of thyroid nodules in patients diagnosed with thyroid nodules at Saint Paul Hospital and Yekatit 12 Hospital in Addis Ababa, Ethiopia. Methods: a one year hospital based retrospective cross sectional study was conducted on 247 patients with thyroid ultrasound and postoperative Histopathology admitted and operated at Saint Paul Hospital and Yekatit 12 Hospital with thyroid nodules from June 30, 2022 to June 30, 2023 G.C. standardized and pretested questionnaire was used to extract all possible information and analysis of data was done by SPSS 26. Using Histopathology result as a gold standard we evaluated the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of thyroid ultrasound Thyroid imaging, reporting and data system. Results: the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of TIRAD system is 73%, 71.1%, 71.7%, 51.9% and 86% respectively. The three high risk US features, Irregular margin, micro calcification and taller than wider has specificity of 94.2%, 94.8 and 93.6%, respectively. Experience of US personnel and duration between ultrasound and histopathology result has statistically no significant effect on the accuracy of thyroid imaging, reporting and data system. Conclusion: thyroid imaging, reporting and data system is an appropriate and non-invasive method for initial assessment of thyroid nodules in our routine practice. The three best ultrasound features that pose a higher risk of malignancy are irregular margin, taller than wider and micro calcification. Thyroid ultrasound examinations done by senior radiologist and radiology resident do not affect accuracy of thyroid imaging, reporting and data system significantly. Keywords: thyroid nodule, thyroid ultrasound Thyroid imaging, reporting and data system, Histopathology, and diagnostic accuracy