Table 2.

Criteria adopted for the definition of the TIRADS system score categories.

Criteria	Definitions
Composition	Cystic = 0 Spongiform = 0 Mixed solid and cystic = 1 Solid = 2
Echogenecity	Anechoic = 0 Hyperechoic or isoechoic = 1 Hypoechoic = 2 Very hypoechoic = 3
Shape	Wider-than-tall = 0 Taller-than-wide = 3
Margins	Smooth = 0 Ill-defined = 0 Lobulated or irregular = 2 Extrathyroid extension = 3
Echogenic foci	None or large comet-tail artifacts = 0 Macrocalcifications = 1 Peripheral calcifications = 2 Punctate echogenic foci = 3