How to create 3D segmentation using level-set?

Hello, I have a function using level-set method to segment a part of image that I need. Now I need to trasnfer it to 3D and I have no idea how. Output of function looks like this:

figure(2); imagesc(Img,[0, 255]); axis off; axis equal; colormap(gray); hold on; contour(phi, [0,0], 'r'); hold on; contour (phi2, [0,0], 'y');

where phi and phi2 are two inicial contours for leve-set

I will be glad for any advice. Thanks!