shape(2D) 3D Slicer radiomics slicer radiomics

After pouring 2D ultrasound images into 3d slicer, segmentation was performed. Enter the radiomics module and enter the volume that cannot be found.
Looking for the answer on the Internet, some people can find the volume by using volume to convert scalar, but after the conversion, radiomics is used to extract the features, and the result is that the features of “shape 2D” are missing, and the software treats the 2D image as 3D. But I only need to use radiomics to extract the circumference, area, and so on of ROI in 2D images. Can someone please answer this question?
Thank you