Thyroid Imaging Reporting and Data System and Ultrasound Elastography: Diagnostic Accuracy as a Tool in Recommending Repeat Fine-Needle Aspiration for Solid Thyroid Nodules with Non-Diagnostic Fine-Needle Aspiration Cytology

Abstract

The Thyroid Imaging Reporting and Data System (TIRADS) has been found to be accurate in the stratification of malignancy risk, and elastography has been found to have a high negative predictive value in non-diagnostic thyroid nodules. Through assessment of 104 solid non-diagnostic thyroid nodules, this study investigated the role of both in recommending repeat ultrasonography-guided fine-needle aspiration for solid thyroid nodules with non-diagnostic cytology. All nodules were classified by TIRADS (categories 4a, 4b, 4c and 5), and elastography scores were assigned according to the Rago and Asteria criteria. The malignancy risks for TIRADS categories 4a, 4b, 4c and 5 were 12.5%, 25.0%, 25.8% and 16.7%, respectively. Elastography revealed the highest diagnostic performance for TIRADS category 4a, with a sensitivity, specificity, negative predictive value, positive predictive value and accuracy of 100%, 85.7%, 100%, 50% and 87.5% for the Asteria criteria. Observation may be considered for non-diagnostic solid nodules that have no other suspicious ultrasonographic features and are also benign on real-time strain elastography using the Asteria criteria.