Disc Lesions & MRI
Of all the back injuries, few are as misunderstood as disc lesions. In the low back, there are 5 bones (vertebrae) with 5 discs in-between the bones. These discs can and do get injured. With excessive, sudden and/or prolonged loading of the disc, disc fibers may tear. These small tears act like most other tissue- they cause swelling, inflammation, bleeding and pain. These tears cannot be detected up on traditional x-rays.
In the 1980's. a new technology emerged, which was designed to help physicians examine tissue injuries, such as disc lesions, called magnetic resonance imaging or MRI. MRI's, per definition, we designed to detect water content in tissues, In certain pathologies, increased or decreased water content correlates to injury or disease.
Unfortunately, this has lead to an increased awareness or (and blaming of) disc lesions. Many patients, often view these images as the "gold standard" for proving there is something wrong with their disc, while this may not be the case:
- Studies now confirm that approximately 40% of people have a bulging (swollen) disc in their back without any low back pain.
- MRI studies now show that when a patient has a bulging disc on MRI and a second (repeat) MRI is taken a few months later, in many cases the disc bulge will either be smaller or gone.
- MRI's are static. It is a picture in time. Just because someone has a "bulging disc" on an image, nothing is known about the properties of the disc during normal, functional movement. IT could very likely be that the "normal" disc above or below may be the patient's source of pain.
- MRI's are conducted with the patient lying down. When a disc is swollen, it will push down, further enhancing the idea of a "bulging disc."
- Disc are swollen on average 20% more in the morning, compared to evening. The time of day that an MRI is done, may thus affect the results of the MRI.
The reality is that many people may have what appears to be a "bulging disc" on tests such as MRI and may/may not be the source of their symptoms. The good news is that many physicians are not downplaying MRI findings, unless the MRI findings match a patient's symptoms, history of injury or disease, other tests and physical examination.
*For more information- ask your physical therapist. This is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.
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