'Whole-Body' MRI — An Appropriate Gift?
Wondering what to give that special someone who already has everything? How about an MRI? In recent years, magnetic resonance imaging (MRI), other forms of whole body scanning or sophisticated heart tests are already being offered to anyone willing to pay the price but more recently, they have been recommended as “stocking stuffers,” a unique gift to provide “peace of mind.”
What’s an MRI?
The technology that allows an MRI to provide pictures inside our bodies relies on the fact that the chemical building blocks of our organs respond to strong magnets. The atoms within our tissues “line up” when a strong magnet is applied and when the magnetic field is release, the atoms “relax” and give rise to energy signals; a computer then interprets these signals into images of our anatomy. What was once unseen and impossible to evaluate short of surgery can now be readily measured, analyzed, and monitored over time. Among the most common and helpful applications of MRI is imaging of the brain, spinal cord, knee, and organs of the abdomen and pelvis.
Is an MRI a Good Gift Idea?
At first glance, getting a peek inside the body before there are symptoms of trouble may seem like a good idea. However, the belief that “knowledge is power” may sometimes be untrue, a medical myth that relies on intuition rather than facts. Although it is true that a normal MRI result could provide reassurance, there are several reasons to think twice about buying the test for someone (or for yourself):
Cost – these tests are not cheap and are not usually covered by insurance unless ordered for a reason by your own healthcare provider; costs for an MRI range from $400 to $1200, depending on how much of the body is scanned.
False-positives – MRI scans are very sensitive – that is, they don’t miss much. But, as a result, they frequently pick up things that turn out to be nothing important. If your scan showed an abnormality, your doctor might recommend additional tests, sometimes including a biopsy or even surgery; in the meantime, you’d probably be very worried about whether the abnormal finding was something serious. Yet, in the end, most abnormalities on scans of people without a medical reason for the test are irrelevant to one’s health – that is, the results are false-positives and you’d be better off not knowing they are there.
False-negatives – A normal MRI does not guarantee perfect health because not every disease shows up on an MRI; so even when the test returns normal, disease could be present (false-negative results) and those people will be falsely reassured.
Lack of study – Performing MRIs on people who are healthy and have no symptoms could cause more harm than good; for example, if it lead to additional testing and invasive investigation of abnormalities detected, some complications are inevitable. Since definitive studies of this approach have not been performed, it is hard to advocate such an expensive and potentially misleading test for “peace of mind.” If your result is not normal, peace of mind will not come easily.
Information Is Power — Or Is it?
I once cared for a patient who had fevers day after day without an identifiable reason; the usual and appropriate tests for infection and other common causes of fever were inconclusive or unhelpful. A medical student asked why we were not performing even more tests since, “after all, tests will give us more information and information is power.” It dawned on me then how that statement is only true if the information is good information. There are times when information is not power – in fact, bad information is often worse than no information at all. My patient turned out to have malaria – the key was ordering the right test, not ordering more tests simply because they are available.
It is a statistical fact that for imperfect tests (which includes almost all medical tests), screening large numbers of seemingly healthy persons will usually produce more false-positive results (abnormal results that turn out to be meaningless) than true-positive results (abnormal results that truly represent a disease). For this reason, it is best to understand the limitations of the test and try hard to prove that it provides benefit in excess of risk, before offering the test as a screen for reassurance or early detection of disease. That has not yet happened for MRI.
The Bottom Line
In recent years, companies that own expensive imaging instruments have begun to promote the tests directly to consumers. This is a new phenomenon – 20 years ago, you needed a good reason and an order from your doctor to have a CT scan or even a regular x-ray. If you walked into your doctor’s office requesting a total body scan or other sophisticated imaging, your doctor would probably have explained how there was no reason to have the test and would not order it. Now, in many locations, your own healthcare provider can be bypassed.
Perhaps it will turn out that this approach is useful and will lead to earlier disease detection, earlier treatment and better outcomes. Then again, chances are good that if you give someone an MRI test for the holidays and the results are not normal, they may wish you had just given them another sweater instead.
