ACR TI-RADS vs K-TIRADS: Substantial Agreement but Different Sensitivity-Specificity Trade-offs in 481 Thyroid Ultrasound Images

ACR TI-RADS and K-TIRADS show substantial inter-system agreement (κ=0.61) and similar AUC (p=0.52) across 4 readers, but ACR TI-RADS yields higher sensitivity and NPV at the cost of lower specificity and more unnecessary biopsies — retrospective, single cohort.

• Retrospective diagnostic-accuracy study; 4 experienced radiologists independently scored 481 thyroid US images (157 benign, 184 malignant, 140 negative) using both ACR TI-RADS and K-TIRADS.
• ACR TI-RADS had significantly higher sensitivity and NPV but significantly lower specificity, PPV, and unnecessary biopsy rate vs K-TIRADS (all p<0.001); mean AUC did not differ (p=0.52), suggesting equivalent overall discrimination with different operating points.
• Key limitation: retrospective, single-cohort design with no external validation; generalizability to non-Korean practice settings and less-experienced readers is uncertain.

RadPigeon summaries are original and for information only. They are not clinical advice.