A Novel Noninvasive Approach for Evaluating Suspicious Cervical Lymph Nodes in Papillary Thyroid Carcinoma-Superb Microvascular Imaging.

Purpose: To assess the diagnostic performance of superb microvascular imaging (SMI) versus color Doppler flow imaging (CDFI) and fine-needle aspiration thyroglobulin (FNA-Tg) in detecting indeterminate cervical lymph nodes (CLNs) in papillary thyroid carcinoma (PTC) patients.

Methods: We prospectively analyzed clinical and imaging data from 74 PTC patients with indeterminate CLNs undergoing FNA biopsy and Tg measurement. Analyses included: (1) univariate comparison of benign versus malignant CLNs; (2) Spearman correlation between imaging features and pathological findings; and (3) receiver operating characteristic curve assessment of diagnostic accuracy.

Results: Among 43 benign and 31 malignant CLNs, significant differences were observed in gender (p = 0.026), age (p = 0.041), FNA-Tg levels (p < 0.001), and diagnostic outcomes for CDFI (p = 0.001) and SMI (p < 0.001). FNA-Tg (r = 0.946), SMI (r = 0.707), and CDFI (r = 0.403) correlated with pathology (all p < 0.001). FNA-Tg showed superior accuracy (AUC = 0.977) versus SMI (AUC = 0.856) and CDFI (AUC = 0.704). SMI detected more vessels than CDFI in benign (2.00 vs. 1.00) and malignant nodes (3.00 vs. 2.00) (p < 0.001), with higher overall counts (2.53 ± 1.47 vs. 1.50 ± 1.13, p < 0.001).

Conclusion: SMI outperformed CDFI in microvascular visualization for indeterminate CLNs in PTC. Although FNA-Tg remained the most accurate diagnostic method, SMI served as a valuable noninvasive alternative, especially when FNA-Tg was contraindicated or inaccessible.