No, they don't do them to everyone and I don't know for sure why they did it to me. I didn't have a MRI with the first surgery, just the arthrogram. The second surgery, they did a MRI and no arthrogram. I have no clue how they choose which procedure to do but!!!!Nobody will ever catch me off guard again, with an arthrogram. That is the most painful, god awful thing I have dealt with, while being totally awake. I have a pretty high pain tolerance but that was ridiculous...