Will an MRI scan help diagnose the cause of my lower back pain?
In the overwhelming majority of cases MRI scans &, especially x-rays, will not be helpful in diagnosing or treating the cause of your low back pain. Most people are under the false impression that an MRI scan will identify the cause of their pain.
The comments I hear the most from the average person suffering from back pain are generally along these lines:
“If I can just get a scan done then I can figure out what is wrong and get it fixed.”
“What if something is missed & it stops me from recovering”
“I think I have sciatica or a trapped nerve. I am getting a scan to see if it is serious.”
Because these comments are repeated over & over by patients, it reflects a general misperception amongst the public regarding the benefits of scans for helping to treat back pain.
The reality is that a scan shows a lot of structures with varying degrees of abnormalities that are present both in those with and without back pain. This is the reason that medical guidelines have been updated & are very clear in stating that having MRI scans of the back do not improve a patient’s outcome, either in terms of pain, function, or quality of life.
About 55 percent of individuals with NO BACK PAIN will have a disc bulge when an MRI of their back is performed.
Do I need an MRI to diagnose a disc bulge in my low back?
Many people believe that once they have been diagnosed with a disc bulge they need an MRI to confirm it and to assess the extent of the damage. The issue with this is that a good Physiotherapist or Chiropractor will likely be able to confirm the presence of a disc herniation based on testing in the clinic. These tests are more accurate from a therapeutic perspective than scans of the back since, as mentioned above, scans often show things like disc bulges even in people who have no back pain.
Therefore, given that scanning a random individual with no back pain more likely to show a disc bulge than not, it could be argued that:
- The scan is of little value in diagnosis &
- Once a diagnosis of a disc bulge has been made clinically then an MRI scan will not change the diagnosis or physiotherapy management of that condition.
I will often get calls from patients saying that they are holding off physiotherapy treatment until they have the results of their MRI (often from another well-meaning medical professional); however, the scan in the overwhelming majority of cases has no influence on the treatment provided for their lower back pain. Patients are often not very receptive when it comes to being persuaded of the lack of utility of MRI scans in the management of their back pain. This is where a GP, physiotherapist, or chiropractor can end up agreeing to refer for a scan even though they know it is unlikely to be of any real benefit.
My MRI scan shows degeneration. Is this something to worry about?
Virtually any individual who undergoes an MRI scan over the age of 30 will have some sort of ‘abnormality’.
Part of the natural ageing process involves changes in our collagen. For example, our skin develops wrinkles & pigment changes. While these might be deemed abnormalities, they are also part of the natural ageing process. Like that mild or moderate degenerative changes, depending on your age, are also quite a standard finding on an MRI scan, & therefore not something that you should unduly worry about. Disc degeneration or herniated discs are often reported from scans and are not something for you to panic about.
Science is becoming more aware of risks of MRI scans
Healthcare practitioners such as physiotherapists and chiropractors are becoming more aware of the limitations of scans in aiding back pain recovery. However, convincing a client that they do not need a scan can prove challenging. I know from having injuries myself that you are naturally curious and there is a part of you that wants to see the area and identify ‘what is wrong’, even if the research suggests it is not beneficial. Despite medical advice to limit such imaging, research published in the British Journal of Sports Medicine in 2019 shows that MRI’s and other scans for lower back pain have increase by 53.5 percent between 1995 and 2015.
Worryingly, more recent findings in the literature have identified the negative effects of having back scans. Research shows that those who undergo MRI scans can actually end up with more back pain. This is because after the MRI is performed a report of the findings will be written up by a radiographer. The report will often contain findings of areas where there is bony growth or discs bulging to varying degrees. The problem is that because such findings are present for most people and can therefore be deemed normal. However, the fact that they have been written onto a medical report suggests to the patient and physician that they are abnormal and therefore are a serious issue that should be a cause for concern. This is why MRIs can frequently lead to unnecessary surgeries and can fail to alleviate symptoms as they may not target the source of the symptoms.
If considering a spinal x-ray, it is important to be mindful of the radiation exposure from such imaging. X-rays are recognised as causing cancer in humans. The average radiation from a spinal x-ray is 75 times greater than that of a chest x-ray.
Are my MRI findings really abnormal?
Unlike other medical reports which primarily focus on abnormal findings, MRI scans can report deviations from the ideal spine that can be deemed normal. The MRI report refers to deviations relative to the ideal spine of a young person with perfect spinal curves. The problem here is obvious: most people going for MRI scans are not in this age bracket and therefore the supposedly “abnormal” findings are in fact normal for that age group. This fact is key in understanding the confusion that arises when interpreting the results from MRI scans. After the introduction of MRI and CT scans in the 1970s, medics began using the scans to make a diagnosis as opposed to using them to confirm or refute an uncertain diagnosis.
Questions to ask when you have a back scan:
The main questions you should ask your physiotherapist or chiropractor is this:
- Can the finding on my MRI report explain all of my symptoms?
- If the findings from the MRI report are the sole cause of my symptoms then why do my symptoms fluctuate?
- Those with a previous diagnosis of a disc bulge should ask their physiotherapist why their symptoms disappeared or improved before returning again. Given that a disc bulge as viewed on an MRI does not tend to change position when someone is suffering from a flare in before and after the onset or eradication of symptoms
The linking of symptoms to findings on MRI scans are often illogical
These elements are difficult to explain based on MRI findings alone. These “abnormalities” reported on scans can create serious concern for patients. Things such as bulging discs have seriously negative connotations for patients and can create a degree of panic, even though these things may not be the cause of their symptoms at all. This diagnosis can lead to fear avoidance of activity and exercise which can create more back pain in the medium to long-term.
In most cases, the identification of a serious disc injury or other spinal conditions of concern is more accurately performed by a clinical assessment carried out by a Physiotherapist or Chiropractor who specialises in back pain. They can identify quite readily those relatively rare cases where patients actually do require onward referral for an MRI scan.
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