Table 2.

Tsukuba scoring system

Scoring	Figure	Color distribution	Significance
1		The entire lesion is evenly shaded green	The strain of the nodule is even. The nodule is entirely soft. It often indicates a benign lesion
2		The lesion is shaded with a mosaic pattern of green and blue, and the green area is bigger than the blue area	Strain in most areas of the nodule, while few areas with no strain. The nodule is mostly soft. It also indicates a benign lesion
3		The middle is blue and the periphery is green	The core area of the nodule is stiff and hardly strain, while the peripheral area is still soft and has strain. It indicates a suspicious lesion usually
4		The entire lesion is all blue	No strain in the nodule, it is entirely rigid. It also indicates a suspicious lesion
5		Blue area extends from the nodule boundary to the surrounding tissue	No strain in the nodule and the surrounding tissue, both of them are rigid. It also indicates a suspicious lesion