The initial MRI was lower back - the thought at that stage was sciatic nerve pinched where it appears from the spine (so MRI not in the correct area). Second MRI picked up the deterioration of the tendon hence the decision to go see Mr Brick and try PRP, which then lead to surgery.
TBH I think it's all to do with the skills and experience of the person reviewing the scans - it isn't a particularly clear image!
In any case, good luck with it, and I hope you find some resolution. My only advice would be to go see the best person you can, and someone who appreciates the sport you do.
I'm still on one crutch some 5 weeks after surgery. Sitting is still a problem, and I haven't done any exercise (so am going slowly insane...). Perhaps I shall try a gentle swim at the weekend?