MTF 2D from MTF 1D

Dear all,

I am dealing with a problem that I am not able to solve... Unfortunately, my phantom doesn't have any proper feature in order to extract directly the 2D MTF (neither with PSF or ESF). But I can extract the 1D MTF in each direction (x and y) separately.

Is there any way I can get the 2D MTF from these two 1D MTF in each direction?

Please help me!!

Thank you!!