CAUTION NEEDED Without adequate context the findings of MRI scans can be misleading, even harmful.
A picture paints a thousand words, they say. And sometimes ‘they’ are right, but for those thousand words to make any sense, some context is required. Think about it; looking at your own baby photo is interesting for you, but can be quite emotional for your parents who are reminded of the pregnancy, the delivery and taking a baby home.
Artwork is the same, one man’s Mona Lisa is another’s Dogs Playing Poker. A picture by itself might tell a story, but usually the context is more important than the picture itself.
What do art and photography have to do with the world of physiotherapy? Not a lot, but let’s talk about pictures in the form of Magnetic Resonance Imaging (MRI) scans, and specifically whether there is sometimes more harm than good in getting scanned.
For many the most likely scenario that would lead to them undergoing a MRI scan is back pain. We all know someone who has a bad back that isn’t getting better and so is referred for MRI. Invariably that person has a scan and is told they have a disc problem; a bulge or degenerative changes that need managing.
But as more research is done, the more it is becoming apparent that scans might be giving the whole picture, but not the whole context. Because while you might have a bulging disc on MRI, that might not be the cause of your pain. And the person next to you, who has never had a minute of back pain quite possibly also has a bulging disc.
How can that be? Surely pain is inextricably linked to tissue damage? The answer is no.
Context is everything
A study published in the American Journal of Neuroradiology in 2015 showed that the prevalence of lumbar disc degeneration in asymptomatic (pain free) individuals rose from 37 percent at age 20 to 96 percent at 80 years of age. In other words, more than a third of 20 year olds who don’t have back pain do have degenerative changes in their back.
This rises above 50 percent by age 30, and to 80 percent by age 50. If you are over 30 you have a better than average chance of seeing a ‘pathology’ on MRI, regardless of whether you have back pain or not, and this includes bulging or ‘slipped’ discs.
It isn’t just imaging for back pain that falls somewhat short of explaining root causes. A study published in 2011 found that 96 percent of subjects with no shoulder issues had at least one ‘pathology’ on ultrasound scanning. Another study showed that abnormal findings on knee MRI are almost as common in patients without knee pain as those with pain, and in some instances more common.
What is the answer then? Go back to the dark ages and forget about scanning? Again, the answer is no.
When used well and taken in context, MRI and ultrasound findings are incredibly beneficial in a clinical setting. The most obvious example being in the original use; locating and diagnosing sinister pathologies like cancer. Similarly, someone with back pain who also has significant neurological signs may benefit from scanning and assessment by a specialist. But we should also think of the negative effects.
If you had never had a day of pain in your life but had an MRI that showed a disc problem, it would be difficult not to let the thought fester in your head; do I need to protect this? Imagine you’ve had the occasional back ache over the years and someone tells you that your MRI shows you’ve got the back of an 80 year old; that thought is even harder to ignore.
We know, however, that pain of any sort is not a sign of tissue damage, and conversely that tissue damage doesn’t necessarily cause pain. I often use the paper cut versus gun shot analogy: paper cuts are tiny and could hardly be classed as ‘damage’, and yet they are painful. And that Hollywood thing, where the hero doesn’t realise he’s been shot? That does actually happen. Tissue damage and pain aren’t the same thing.
Take home message
The take home message here is probably more for those of us in the health and medical fields. Without adequate context findings can be misleading, even harmful.
One suggestion is to print statistics on reports, like the ‘normal range’ heading on blood-test results.
The more obvious is to only refer patients for MRI when there are markers suggesting sinister pathologies. At the very least we need to put results in context for patients.
It’s like that photo from your debs; you wouldn’t let anyone see it without first explaining it….
Andrew O’Brien is a chartered physiotherapist and the owner of Wannarun Physiotherapy and Running Clinic at Westport Leisure Park. He can be contacted on
083 1593200 or at www.wannarun.ie.