Diagnostic Value of Contrast‐Enhanced Ultrasound for <scp>TI</scp> ‐ <scp>RADS</scp> 4–5 Benign Thyroid Nodules: A Propensity Score Matching Study

BACKGROUND: Conventional ultrasonography has limitations in distinguishing benign from malignant thyroid nodules classified as ACR TI-RADS 4-5. METHODS: We retrospectively enrolled 152 benign and 228 malignant papillary thyroid carcinomas (all ACR TI-RADS 4-5, confirmed by postoperative pathology). Propensity score matching was performed to balance conventional US features. RESULTS: After matching, 81 pairs of benign and malignant nodules were obtained. In this surgically treated cohort, multivariate analysis revealed that absence of filling defects on CEUS was independently associated with a higher likelihood of malignancy (p < 0.05). Incorporating CEUS features into the diagnostic model improved the AUC from 0.699 to 0.780. Notably, benign nodules with different pathological bases exhibited distinct CEUS manifestations. CONCLUSION: In this retrospective propensity-matched surgical cohort, CEUS provides incremental diagnostic value for ACR TI-RADS 4-5 thyroid nodules beyond conventional US. The combination of CEUS and conventional US improved diagnostic accuracy compared with conventional US alone. However, prospective studies in unselected patients are needed to validate these findings. The complex pathological underpinnings of different benign nodule types may contribute to variations in their CEUS manifestations.