My daughter who is 6 recently had an appointment with a new doctor who specializes in Moya-Moya and other brain disease.  In fact when he heard about her, he reached out to us and asked if he could see her. 

During the appointment we talked about many things and I thought he was great and had a wealth of information.  For the next appointment he is going to do a Doppler Ultrasound to determine the blood flow in her brain. 

Has anyone else had this done? 

Yes, my daughter has had two.  First one was done before her first surgery and the second was done in between surgeries.  From what I understand, it's does exactly what it means...determines blood flow throughout her neck and brain.  What they use is about the size of a marker and move it slowly around the neck and head. For my daughter it was painless, but she had a little tenderness on the second one, due to her first surgery only being 4 weeks prior.  I believe it took about 45 minutes and the sound reminded me of the heartbeat I heard during pregnancy ultrasound. Our experience was that they didn't tell us what findings they had, alot of it was medical terminology, numbers, etc.  Our neurosurgeon talked to us later about the test results.