MRI of degenerative disease of the lumbar spine.

Low back pain (LBP) is one of the most common reasons that patients seek medical attention. Although acute LBP is generally a self-limiting condition, the estimated cost for this health care problem exceeds $8 billion annually. MR accurately depicts both the morphologic as well as biochemical sequelae of disc degeneration. Additionally, MR is superior in its ability to depict disease processes that can present in an indistinguishable fashion. Although multiple mechanisms have been proposed for the possible etiology of disc degeneration, it remains incompletely understood at this time. In addition to the unknown etiology of disc degeneration, the relationship between degenerative disc disease and LBP has not been firmly established. Substantial percentages of people without a history of LBP or sciatica have been shown to have abnormal imaging examinations. Mechanical compression of neural elements by disc herniation, as well as direct biochemical and inflammatory effects of the contents of the nucleus pulposus upon neural structures, have been proposed as possible sources of LBP. Due to the above, caution is urged before attributing a particular anatomic finding as the patient's source of low back pain.