Objective:

To analyze the diagnostic efficacy of color Doppler ultrasound combined with ultrasound-guided fine-needle aspiration biopsy (US-FNAB) for papillary thyroid carcinoma (PTC) based on C-TIRADS and ATA guidelines, emphasizing their clinical significance.

Key Findings:

• Combined diagnosis of ultrasound and US-FNAB achieved higher sensitivity, accuracy, and discriminative power than either method alone, indicating improved diagnostic reliability.
• C-TIRADS demonstrated significantly higher sensitivity, specificity, and accuracy compared to ATA guidelines, suggesting its superiority in clinical practice.
• Inter-observer agreement for C-TIRADS and ATA classification was good (κ=0.81, κ=0.77), indicating reliable classification among radiologists.

Interpretation:

Ultrasound combined with US-FNAB provides higher clinical value for diagnosing PTC, particularly in indeterminate and discordant cases.

Limitations:

• The study was limited to a single center and may not be generalizable to other settings, potentially introducing selection bias.
• The follow-up duration post-diagnosis was not specified, which may affect long-term outcome assessments.

Conclusion:

C-TIRADS is recommended for routine risk stratification before FNAB in Chinese clinical settings.