MRA is used to look at blood vessels, so my best guess is he's looking for obstruction, narrowing, or something to explain the noise he heard. These things can increase pressure (which can affect IIH symptoms), so he may also just be looking to rule them out.

If I remember right, MRA is basically just a MRI with contrast..at least that's the way it seems.

I hope that helps!
Take care, and keep us posted..

Thank you.  Yes, he did say it would be like basically an MRI with contrast that would show the carotid artery and the arteries in my neck.  I have the study next week and the follow up the week after that, so he's apparently not urgently concerned about it.  I'll keep you guys posted.