On the types of surgery , I think many have their own preferred ways..
That is probably why a difference there.

Do you have a copy of the written MRI report?
So members can read the descriptions used?
often mild , moderate , severe helps..
Some will even have measurements listed in the report.

It is good to request a copy , just so you have it for your own records and knowledge.

Use the search tool to look for past posts on fusions etc..
http://neurotalk.psychcentral.com/search.php