Table 3. TI-RADS diagnostic efficiency (%).

TI-RADS	No. of nodules		Sensitivity	Specificity	Youden’s index	Positive predictive value	Negative predictive value
	Benign	Malignant
2	31	2	99.75	6.13	5.87	62.24	93.94
3	358	39	94.78	76.88	71.65	86.41	90.47
4a	66	45	89.04	89.92	78.97	93.20	84.10
4a-4b	7	15	87.13	91.30	78.44	93.96	82.06
4b	30	123	71.46	97.23	68.70	97.57	68.72
4b-4c	4	50	65.10	98.02	63.12	98.08	64.42
4c	10	340	21.78	100.00	21.78	100.00	45.18
4c-5	0	3	21.40	100.00	21.40	100.00	45.06
5	0	167	0.13	100.00	0.13	100.00	39.22

TI-RADS, thyroid imaging-reporting and data system.