Elastography enhances diagnostic accuracy of ACR TI-RADS in thyroid nodule evaluation.

Abstract

The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) incorporates conventional grayscale ultrasonography (US) as the only imaging technique without considering the clinical and demographic characteristics of patients. This study assessed whether the addition of demographic information, color Doppler US (CDUS), and strain elastography could enhance malignancy risk stratification beyond the current ACR TI-RADS criteria. This prospective study enrolled 556 adult patients with thyroid nodules ≥10 mm who were referred for fine-needle aspiration (FNA) according to the ACR TI-RADS recommendations. All nodules underwent standardized US evaluations and vascularity assessments using CDUS and strain elastography, with cytological analysis performed according to the Bethesda system. Surgical pathology was the gold standard for malignancy when available. Applying elastography ratio (ER) thresholds (>1.60, >0.44, and >0.54 for ACR TI-RADS categories 3, 4, and 5, respectively) as an additional criterion for FNA reduced the number of procedures from 501 to 260, without missing any malignant cases. Notably, elastography demonstrated an excellent discriminative performance in ACR TI-RADS 3 nodules (Youden index 0.994, AUC 0.994), supporting its value in improving risk stratification in this challenging, predominantly benign category. Integrating elastography into the ACR TI-RADS framework can optimize FNA utilization in the management of thyroid nodules by reducing the number of unnecessary aspiration biopsies.