I believe an MRI scan by a radiologist who knows what they are looking for would be better. I would say 1.5T MRI at a minimum, 3T MRI would be better. Stay away from 0.75T Open MRI as it won't have enough resolution (same with x-ray/CT).

Do you have regular neurologist? A neurologist or vascular TOS expert would be the best to order the MRI study.