Calculate surface area of a XCT Volume

Operating system:64 bit
Slicer version:4.11.20210226
Expected behavior:
Actual behavior:

I would want to calculate the surface area of an XCT Volume. Could anyone help me with some ideas of how to approach it?

I attach the screen with the volume.

Thanks

You can just segment it (probably just threshold) with the Segment Editor and then use the SegmentStatistics module.