Thank you for the additional info. My husband had a severe allergic reaction to the contrast medium which left him with Stage 3 kidney failure immediately. He has had an MRA w/o contrast that showed nothing. The Mayo doc who ordered the MRA opted to not pursue things further. Yesterday the University of Iowa responded to the NeuroOpthamologist he sees locally with an appointment to evaluate him there in October. We are hoping to get some answers and hopefully treatment to prevent this life impacting syndrome. I will be interested to see how you make out. Good luck!