If there is one thing I have learned for sure, an MRI does not show the extent of the disc that is damaged. It can miss fragments thats have broken off and press on your nerves. Only upon opening you up will they be able to see how messed up you are. My MRI just showed an extrusion, but no mention of large fragments, etc. Of course I am sure that expertise of the MRI reader has something to do with this also.