"Mild Hernia in L3 L4"

For the past 2 months i have had serious back pain in my lower back. I hurt it at work. I got the doc to give me an MRI about a month and a half ago. The doc told be that i had a mild Hernia in L3 L4, but she said that the hernia probably wasn't what was hurting me since the pain was so low.... Is there anything else that could be messed up in my back that wouldn't show on an MRI?

[upstateNY]

This PDF file is of the opinion that not all muscle tears show up on lower back MRI's:

OC]
“Doctor, I have a herniated disc and I'm told that you can't do ...
File Format: Microsoft Word - View as HTML
MRIs do not show muscle tears in the lower back. Again, do you want a diagnosis about your back condition without examining the muscles? ...
www.wevegotyourback.org/files/MRI10-03withoutoffer.doc