Table 1.

Criteria and diagnostic value for CEUS in the differential diagnosis between benign and malignant thyroid nodules

Study	Year	Diagnostic criteria for malignancy	Sensitivity	Specificity	Accuracy
Schleder et al. [14]	2015	No wash-out or wash-out in late phase	21/26	69/75	90/101
Jiang et al. [15]	2015	Non-homogeneous, hypoenhancement	44/49	67/73	111/122
Ma et al. [21]	2014	Heterogeneous enhancement	85/94	71/78	156/172
Zhang et al. [22]	2010	Heterogeneous enhancement	45/51	49/53	94/104
Zhang et al. [24]	2016	Low enhancement or a peripheral irregular ring	82/82	49/75	121/157
Cantisani et al. [26]	2013	Heterogeneous, absent wash-in	15/19	31/34	46/53
Wendl et al. [28]	2016	Accelerated TTP at the center of the lesion	16/20	19/30	35/50
Nemec et al. [29]	2012	Relative enhancement of 2.35 as the optimal threshold	10/13	22/33	32/46
Yuan et al. [31]	2015	Irregular shape of enhanced lesions	35/37	36/41	71/78
Zhang et al. [37]	2017	Heterogeneous enhancement	58/75	230/244	288/319
Li et al. [42]	2015	Non-homogeneous and low enhancement	44/50	24/30	68/80
Giusti et al. [43]	2014	TTP index >0.98	7/13	46/50	53/63
Deng et al. [45]	2014	Hypoenhancement	46/56	101/119	147/175

CEUS, contrast-enhanced ultrasound; TTP, time to peak.