“Doc, my back is killing me! I think I need an MRI.”

I don’t know if you’ve ever uttered those words, but I can tell you I’ve sure heard them … more times than I can count.  And believe me, I get it. When you’re in pain, all you care about is finding out what’s causing it as soon as possible so you can get rid of it as soon as possible. It’s quite tempting to believe that the answer to all your back troubles can be revealed by a quick nap in the MRI tube. The frustrating truth, however, is that it usually can’t. Even worse, that nap often leads to unnecessary treatments including increased procedures, risks, costs, and ultimately, postponed diagnosis and treatment.

The current issue of The Back Letter (a monthly publication by Lippincott, Williams, and Wilkins) has an interesting update on this very topic, noting: “The American College of Physicians recently initiated a campaign to end routine imaging for low back pain on the premise that it has no clinical value and often leads to a harmful cascade of events for patients.”

The key phrase there is “routine imaging.” In other words, spine imaging (x-rays, CT scans, and especially MRIs) should not be the rule but rather the exception, as it is rarely needed or even helpful. The fact is, the vast majority of adults have detectable spine abnormalities (e.g. bulging discs, degeneration changes) despite having no pain.

Presenting her study on medical care provided post-MRI to the recent International Forum for Primary Care Research on LBP in Australia, Barbara Webster, PA-C concluded (as quoted in The Back Letter): “… that decisions regarding future interventions were very much driven by the findings on the MRI—whether they were clinically relevant or not.”

The Back Letter sums it up this way:

… having an MRI appears to be a common pathway for most individuals who go on to have other procedures. And it seems likely that the visualization of anatomic abnormalities on MRI scans—abnormalities that are almost always present on the scans of middle-aged adults—is a significant driver of that process. Most of those abnormalities would have no clear relationship with back symptoms. Yet once they are discovered, they are difficult to forget—for patients and providers alike.

Translation: the mere presence of findings on MRI makes both patients and doctors feel obliged to do something even though that something is usually unwarranted.

This realization will come as a shock to the many people who regard the MRI as the Magic 8-Ball of medicine, magically revealing the secret of what ails them.  The reality, however, is that an MRI is nothing more than a detailed picture, one with a tendency to add to rather than lessen the confusion of getting an accurate diagnosis. The more detail, the more confusion over what any of it means. For that reason, the MRI is useful only to the degree with which it correlates with other pieces of the puzzle (e.g. symptom details, physical examination findings, and results of other tests).  It is no better at providing a definitive answer than is opening up the hood of your car when you hear it making a funny sound. After all, you’re almost guaranteed to find a grimy engine block, a frayed fan belt,  maybe a missing radiator cap or any number of other “abnormalities,” but these things mean very little in and of themselves, and may have nothing to do with the funny sound. In fact, they do little more than prompt the same question that most findings on a spine MRI should: “OK, so what?”

The bottom line is that spine MRIs can be very valuable tools but only if ordered for the appropriate reasons, put in proper clinical context, and correlated with other pieces of the puzzle. When it comes to back pain, they’re not the end all be all they’re cracked up to be. They’re barely the end some be some, as the American College of Physicians has made clear. In most cases, MRIs are unnecessary and delay proper treatment; at worst, they lead to potentially harmful interventions. So the next time your doctor declines to order that MRI you requested, know that it’s not some callous attempt to contain costs. Odds are, it’s to spare you unnecessary testing, hassle, risk, and delayed treatment.  In other words, odds are it’s just the correct call.

Kerrie M. Reed is a physiatrist who blogs at Your Functional Health. 

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