Rex,
I was not indicating that both AVM and aneurysms are either common or benign. I was responding to Chris' Description of her AVN as being not problematic but being watched, and to the fact that a large enough AVM or aneurysm in the brain that would cause a problem being most likely picked up on MRI.

I also know that when Teri spoke to us on last year's MSF, she mentioned that she'd had an MRI, MRA, SPECT, and PET so I'm sure they were aware of the aneurysm if it was in the brain.