Table 1.

Sonographic features investigated

Feature	Definition
Presence of focal lesion	Lesion can be focal or dispersed
Shape of lesion	Lobulated, oval, or eccentric
Definition of border	Grade 0: well defined Grade1: ≤1/3 of border poorly defined Grade 2: 1/3 to 2/3 poorly defined Grade 3: ≥ 2/3 poorly defined
Echogenicity	Anechoic; Isoechoic; Hypoechoic; Hyperechoic; Mixed
Homogeneity	Grade 0: homogenous Grade 1: ≤1/3 heterogeneous Grade 2: 1/3 to 2/3 heterogeneous Grade 3: ≥ 2/3 heterogeneous
Internal structure	Solid; Cystic; Calcifications
Acoustic shadowing/enhancement	Absent; Present
Vascularity	Hypovascular ≤2 vessels Hypervascular>2 vessels inside the lesion