Table 2.

Comparisons of contrast enhanced ultrasonography features between the case and control groups

Features	Case (n=143)	Control (n=161)	χ2	P-value
Level of enhancement
High	105	29	94.35	<0.001
Equal or weak	38	132
Uniformity
Even	49	116	43.57	<0.001
Uneven	94	45
Radius expansion
Yes	103	38	71.41	<0.001
No	40	123
Edge shape
Blurry	107	44	68.34	<0.001
Clear	36	117
Direction of enhancement
Concentric	108	137	4.43	0.035
Eccentric	35	24