I think you are right about getting a more accurate picture being off Diamox for imaging, but I don’t really know how many days you need to go off of it.
And, be sure not to be dehydrated either, the day of imaging.
I had a CINE flow study done last year, which ended up being a complete waste of time and money because I was severely dehydrated due to an adrenal crisis (didn’t know it was a adrenal crisis at the time). I was diagnosed with Addisons a couple weeks later, but nearly died before it was figured out.
All that to say yes, we want our fluids to be at their normal levels for imaging!
I don’t get the symptoms you are describing when Diamox wears off. Same area, but pain and headache not numbness.