MRI Scans: Their Use and Benefits
MRI Scans: Their Use and Benefits
Generally an MRI scan is not the first option for patients who present with lower back pain. Often the basic root causes of pain in the lower back are nothing more than a strained muscle, or a stretched/strained ligament. It is usual for these stresses and strains to heal by themselves or as a result of physiotherapy, within about 6 weeks maximum and often within a month.
An MRI scan is usually requested after a month or so, if the lower back pain shows no signs of abating. The MRI scan is used as a means of establishing what is causing the pain. This could be because the patient is suffering symptoms of sciatica, where the sciatic nerve is being pressurised and the pain is travelling all the way down the leg. Whilst sciatica is relatively easy to diagnose, it is more difficult to diagnose what is causing the pressure on the sciatic nerve: this is where the MRI scan comes into its own. The MRI scan can show causes that are not revealed in XRays.
What Causes Pressure On the Sciatic Nerve?
Often the cause of the pressure is due to a disc in the spine becoming ruptured or protruding, which can be referred to as a herniated disc.
Arthritis or the beginning of arthritis can also cause the nerve to become trapped.
The third main cause of pain is due to the condition spinal stenosis, which is a condition where the spinal canal narrows to a varying degree and this results in the spinal cord and the nerves involved being pinched, or compressed. Again the cause of the stenosis can be caused by a herniated disc, but it can also be simply due to the ageing process.
How Useful Are MRI Scans?
Much has been written about how MRI scans are not all that useful. This is because in, for example, every 100 patients who have lower back pain, only some 5 patients have a really serious illness or a substantial nerve related disorder. The argument is then presented that if 100 patients have an MRI scan, only 5% will be diagnosed with a serious condition. This, they argue, shows that some 95% of MRI scans will be of little or no benefit.
However, this is a very simplistic argument. It should also be viewed in context. Within the NHS, MRI scans are thought of as being expensive, thus they are only used when it is felt that they can be of significant benefit. When MRI scans first became available, patients often requested MRI scans when the consultant felt that there would be little to be gained from the procedure. So the limitations of MRI scans were broadcast, in an attempt to ensure that they were not used too widely.
Yet the fact remains that an MRI scan can show any damage to soft tissue, which simply cannot be seen within an X-ray. This can be very important in terms of eliciting which form of treatment should be used. So although the MRI scan may not be seen as always necessary within the NHS, i.e. it may not be seen as being of ‘significant’ benefit, but it can still be of benefit if the underlying cause of the pain cannot be easily established.
The MRI scan can also quickly show any serious underlying condition and ensure that patients can be reassured if there is no serious illness highlighted within the results of the scan.
Thus your pain consultant is in the best position to indicate whether or not an MRI scan is required for your particular situation. This does not mean that an MRI scan will be used when it is not necessary; it simply means that in the NHS MRI scans are viewed as an expensive option that should be limited in terms of use, but within the world of private medicine, there are fewer restrictions on its use and as such if your consultant suggests an MRI then it should be undertaken. It can save a lot of time simply by ruling out what is NOT causing the pain and focussing on what is causing it and therefore allowing treatment to begin.
