| TI-RADS Category | Size Threshold (cm) | FNA Recommendation | Follow-Up Ultrasound |
|---|---|---|---|
| TR1 | Any size | No FNA | No follow-up |
| TR2 | Any size | No FNA | Optional follow-up if ≥2.5 cm |
| TR3 | ≥2.5 | Consider FNA | Follow-up if ≥1.5 cm (1, 3, 5 yrs) |
| TR4 | ≥1.5 | FNA | Follow-up if 1.0–1.4 cm (1, 2, 5 yrs) |
| TR5 | ≥1.0 | FNA | Follow-up if 0.5–0.9 cm (1, 3, 5 yrs) |