A Practical CEUS TI-RADS Refer to Score and Grading of ACR TI-RADS (2017) for Thyroid Nodules

To construct a contrast-enhanced ultrasound thyroid imaging reporting and data system (CEUS TI-RADS) based on ACR TI-RADS (2017) without changing the initial scores of conventional ultrasound features and reduce unnecessary fine-needle aspiration (FNA) of thyroid nodules.

This retrospective study involved patients with thyroid nodules who underwent conventional ultrasound, CEUS, and FNA from October 2020 to June 2024 in three hospitals. Univariable and multivariable logistic regression analysis was employed to filter out useful CEUS features. A CEUS TI-RADS was constructed to differentiate thyroid nodules between benign and malignant and indicate the necessity of FNA.

A total of 1275 patients with 1521 thyroid nodules were recruited in this study. Arterial phase intensity, wash-out speed, ring enhancement, and enhancement direction (P-value all<0.001) were independent risk factors for malignant nodules in the training cohort. CEUS TI-RADS outperformed in diagnostic efficacy compared to ACR TI-RADS (AUC_[CEUS] =0.94, 0.94, 0.92 vs AUC_[ACR]=0.92, 0.91, 0.80 in training, internal validation and external validation cohort respectively, P-value all<0.001). CEUS TI-RADS could achieve a lower unnecessary biopsy rate (UBR) of 43% (81 of 190 nodules) in the training cohort, compared with 59% (156 of 264 nodules) of UBR in ACR TI-RADS. Similar results were confirmed concerning the validation cohorts.

The CEUS TI-RADS based on ACR TI-RADS (2017) without changing the initial scoring system of conventional ultrasound, was simple and effective in the differential diagnosis of thyroid nodules, which could reduce the unnecessary FNA rate of thyroid nodules than ACR TI-RADS.