Concentricity between two scans?

I have a spec that requires Concentricity with Least Squares Centering of two diameters (about 4 feet across) with 180 data points on each diameter. I figured a scan of each surface would be faster than taken 180 hits each, but it appears that I can't dimension concentricity from either a basic scan, a perimeter scan or a linear closed scan. Am I missing something (I'm new to scanning heads) or is it just not possible?
Thanks in advance.