Dave is right that myelograms are old and mostly out of favor, but they are still used in cases when an MRI can't be done or didn't show enough information. Often, it's an evaluation for surgery - don't let 'em operate Ronnie!
Of course Toni, I had a surgeon tell me that if the MRI with contrast dye was inconclusive, he would know more once inside! But you're right about not having surgery on the lower back. I had 3, first one, about 5 yrs. Relief, 2nd one 2 yrs., 3rd one, no relief at all! For some reason, upper back, or neck spinal surgery, very good outcomes. Lower back, uh-uh!