X-rays vs MRI of the Spine
I’m often asked why Gonstead Chiropractors prefer the use of X-Rays instead of MRI of the spine, here I give some of the reasons why
MRI’s are excellent in displaying both bone and soft tissue. They are also the best modality to image disc pathology as well as more serious pathology such as cancer. In fact, when cancer attacks bone tissue, its only after about 40% of destruction has taken place will x-rays actually highlight the presence of the disease.
However the main disadvantage an MRI of the spine is that it is taken with the patent lying down. This flattens the spines curves, places the spine in a more ‘passive’ state and eliminates the effects of weight bearing on the spine. Even if an MRI could be taken standing, an x-ray is still far better at showing the relationship of the vertebrae as well as the sacrum and pelvis to each other and how they work together as functional unit.
These points are quite dramitcally illustrated by figure 1 and figure 2, images taken of a previous patient of mine. Figure 1 is an MRI of lumbar spine taken lying down and figure 2 an x-ray of the same patient in the standing postion. Firstly note how the natural curve of the spine appears flattened in the MRI compared to the standing x-ray where a fairly normal curve is displayed. More striking however is that on the x-ray the L4 vertebra (red line) has slipped forward in relationship to the L5. This is due to an old fracture at L4 and has lead to instability of this vertebrael. These vertebra looked completely normal on the MRI and would have been missed if the x ray had not been taken.
Essential Information is taken from the patients x-ray, and along with the case history and examination, helps the Gonstead Chiropractor find the exact problems in the spine that require treatment. Furthermore the x-ray gives precise detail to how best to correct these during the adjustment itself.
In summary if the Gonstead chiropractor is at all concerned that a patient has serious pathology or wants to see tissues in more detail they will recommend an MRI. In the vast majority of cases however where they are diagnosing and treating mechanical dysfunction of the spine, they will always want a weight bearing x-ray.
Fact: X-rays do expose the patient to low levels of ionising radiation, however the amount is often compared to that which you would experience if you took a long haul flight.