If I understand correctly, to diagnose and treat the stroke, no. Afterwards, for the purpose of assessing impairment, that's when I believe the MRI is of more use. But I'm NOT a medical professional. This is just what we've been told by them :)
What is there in Terri's brain that is going to show up on an MRI that wouldn't on a CT scan? The CT scan shows EVERYTHING, just like an MRI. I now see some posters are saying she has metal in her head from a previous treatment. I guess that'swhy she's not going to have an MRI. Now maybe we can change the argument to, "Michael intentionally had those wires left in her head so she could never have an MRI" If you think that sounds crazy, just watch.
BTW, in my mothers' case, she had the CT scans at the time of the event, and then again later. Never an MRI.