Fig. 2

The boundary fitted curve of thyroid nodule. The thyroid nodule boundary and boundary fitted curve, where the black solid line is the nodule boundary and the red dashed line is the elliptic curve fitted based on this boundary
The boundary fitted curve of thyroid nodule. The thyroid nodule boundary and boundary fitted curve, where the black solid line is the nodule boundary and the red dashed line is the elliptic curve fitted based on this boundary