MRI instead of CT?

I am under diagnosis of breast tumor and my doctor sent me to CT (computer tomography) to check lungs, pelvis and abdomen for possible metastasis.

I wander, if I can check my lungs by MRI, instead of CT (to avoid radiation)? Unfortunatelly, I did not ask my doctor about it.
He mentioned however that we do mammography and not MRI, couse for MRI is too long queue.
I am not sure if this is a case for CT - MRI, but if yes, I could go for MRI to private clinic, outside public hospital.

The question is, if MRI has the same diagnostic value as CT in this case?

I am asking mainly about lungs, as this forum is about it, but if you can advice also on pelvis/adomen, feel free to do so.