I wish we (therapists) at least had the option to order an MRI or recommend a doctor orders one in difficult cases (I can do the latter but they will just laugh at me).

God, that's awful. The most common sense thing to do there is is to use what's availiable (fMRI) when it is, and if availability is the problem, fill the gaps with questionnaires - those who you're sure about might not need an fMRI, but others might. Which you, as a person who's supposed to sign off on the diagnosis, should be able to order.