Just wanted to add that my daughter had an MRI done at about 10 months - the results were good. However, because of some development issues we had one done at age 2 - the results - she was diagnosed with sws. I would first see if a neurologist would want an MRI and wait until a little over a year as I have heard from others that under a year you won't necessarily get the right results since their so small.
Also be aware that many people are involved in an MRI (dr. that reads it, anesthesiologist, ....) they might not accept your insurance - just beware - I had a lot of insurance fighting to do.
If you have any additional questions about this issue or any other regarding pws, laser you can email me at firstname.lastname@example.org