Can an MRI Hurt You?
At times, an MRI scan can create the illusion of a significant problem.
Posted Jun 15, 2014
Whenever a doctor decides to order a medical treatment, whether it’s an antibiotic or an operation, he or she should carefully weigh the potential benefit and potential harm. Any treatment can cause some form of side effect or negative outcome and we would only assume that risk if the potential benefits outweigh the risk.
This calculation (benefit versus risk) is also necessary when considering the use of a diagnostic test. As a society, we tend to be “test-happy.” Americans undergo much more testing than do people in other post-industrial societies. In particular, imaging studies such as CT (computerized tomography) and MRI (magnetic resonance imaging) scans are done routinely for people with headaches, back and neck pain, and abdominal pain. Looking at these usage rates, some groups have called for decreasing the number of scans we do on the basis that they can be unnecessary at times and serve to increase the cost of health care. On the other hand, these are non-invasive tests that rarely cause any side effects and they are powerful tests that can diagnose serious medical illnesses and reassure those whose scans are negative. Aside from mild discomfort and cost, what problems might arise? Let’s examine the risks and benefits of widespread use of these scans.
When I was a young doctor, we didn’t have the luxury of being able to order a CT (computerized tomography) scan or an MRI (magnetic resonance image). There were certain patients for whom this technology could have saved lives, or at the least spared them from having certain invasive procedures, such as exploratory surgeries looking for tumors or infections. These technologies have revolutionized how we diagnose and treat many disorders, such as kidney stones, appendicitis, brain tumors, aneurysms, blood clots and many other disorders.
Over time, we got used to ordering CT and MRI scans on a routine basis. In the US, we now perform more CT and MRI scans each year per capita than in any other country. These studies make up a large portion of the approximately 100 billion dollars per year spent in the U.S. on imaging studies.
Aside from the cost, there are two types of negative consequences of getting one of these scans. These issues have been carefully delineated in the book, Overdiagnosed by Gilbert Welch, MD and his colleagues. First, there is the likelihood of finding something that is potentially alarming that requires much more testing, but turns out to be a false alarm. An example of this situation is finding a cyst or tumor on a kidney or an ovary. Usually, this problem can be solved when one does more testing and determines that the mass is benign and doesn't warrant medical treatment. This situation drives up the cost of health care and can lead to needless anxiety and occasionally side effects of more invasive testing. These problems are significant when one considers how often this occurs, but generally doesn’t lead to a significant loss of health or wellness.
However, the second consequence of widespread scanning is much more dangerous. This occurs when the images reveal evidence of a disease that is interpreted as something that does require medical treatment and for which the patient is not reassured, but given a worrisome diagnosis. Of course, if that diagnosis were accurate, the test is just telling us what we need to know in order to obtain the best possible medical care. But what would you think about the situation where the scan provides inaccurate evidence of a serious disease and there is no test that can be done to reassure you that don’t have this disease? What would you think if a doctor gave you a diagnosis of a chronic incurable disease on the basis of a scan that has little accuracy? It turns out that this happens in hospitals and clinics every day.
I saw a woman, whom we can call Helen, several years ago who had low back pain for 9 years. The pain began at work one day and had been severe enough to force her to go on long-term disability. She had been told that her back was damaged, although she had no history of a severe injury. Helen had tried pain medications and injections to no avail and she was scheduled to have back surgery in an attempt to alleviate the chronic pain. Her exam showed that there was no evidence of nerve damage since her muscle strength, reflexes and sensation was normal. This is what the MRI of her low back showed:
Severe disc space narrowing at L4-L5 and flattened discs at L2-L3 and L3-L4. Disc bulging with flattening of the spinal cord and narrowing of the outlet for the spinal nerves at L2-L3, L3-L4, L4-L5, and L5-S1. The right L4 and L5 nerve roots are compressed by a disc. The facet joints are swollen and there is spinal stenosis.
Her doctors did what most doctors do in that situation: explain to her that the abnormalities seen on the MRI are the cause of her pain. Since she had severe pain for nine years and none of the treatments had worked, her only hope was to have surgery. (I will discuss the research on surgery for back pain in an upcoming blog, but in brief, surgery for this type of back pain has not been shown to be more effective than non-surgical treatments and the potential risk is higher.)
Helen happened to hear of the mind body program that I direct at Providence Hospital in Southfield, MI and came in for an evaluation. During the course of the evaluation, I found that there was no evidence of damaged nerves (i.e., no loss of sensation of muscle strength in her legs, and no loss of reflexes). In addition, there were several stressful life events that coincided with the onset of the back pain. Armed with this information, I suggested that the abnormalities seen on her MRI were not likely the cause of her back pain and that a mind body treatment approach would be likely to relieve her pain. She was not only surprised by this conclusion, but it made sense to her and she embarked on a program, which can be found in my book, Unlearn Your Pain. Within 3 weeks, the pain of nine years in duration was gone.
How can we explain this miraculous result? There are two important truths that this story reveals: 1) The MRI results did not explain her back pain and 2) Her pain was due to neural pathways, rather than tissue damage (see this blog for an explanation of how neural pathways can cause real pain).
How can an MRI result deceive? There have been several studies showing that MRI’s are abnormal in normal people. When an MRI is done in people who have no back pain, the majority of people have some kind of abnormality. A study by Jensen showed that 64% of people who had no back pain had degenerative discs, bulging and herniated discs, spinal stenosis and other findings. A study of adults with no back pain by Jarvik showed that 83% had degenerated discs and 64% with bulging discs. And a study by Takatalo of healthy 21-year-old Finns found that 50 % had at least one degenerative disc and 25% had a bulging disc. And Boos found that 73% of adults without back pain had bulging discs. (By the way, MRI studies of people with no shoulder, hip or knee pain also show a variety of abnormalities such as rotator cuff tears, labral tears, and meniscal tears, respectively.) When you put these studies together with studies of people with back pain, you find that about half of adults with back pain have abnormal MRI’s and about half of adults without back pain have abnormal MRI’s; and the findings on these MRI’s are virtually identical. In other words, we have no way of determining if the findings on an MRI (unless there is evidence of a fracture, infection or tumor; or if there is evidence of damaged nerves on a neurological examination) are just part of “normal aging” or if they are actually causing the pain. Many physicians simply ignore these studies and assume that all MRI abnormalities are the cause of pain and inform the patient that they have a tissue damage problem. I have seen disastrous results from this approach. It leads to more worry, fear and anxiety, which only serves to make neural pathway pain much worse. It also leads to invasive procedures, such as injections and surgery, and the use of opiate medications that can cause their own set of problems.
Last week, I saw a man named David who had surgery based upon an MRI that showed very minimal changes, which had not worsened over the three years that he had back pain. Unfortunately, that surgery led to two more surgeries due to complications and did nothing to reverse his pain. His pain began to reverse upon entering the mind body program and learning how to use his mind to calm neural pathways that were causing his pain.
It is a difficult task to use technology wisely. It is tempting to overuse MRI scans in the well-intentioned search for disease that requires medical treatment. An MRI is a wonderful non-invasive test to diagnose serious medical problems, but we must be extremely careful not to over-interpret these scans. The majority of people with back pain do not have a tissue damage cause for their pain, despite having abnormal findings on an MRI. If we begin to look at the whole person in the context of their life history and the connection between stressful events and pain, we will discover the actual cause for back pain in many. This approach can decrease needless medical testing and procedures and lead to improved outcomes for a condition that affects millions.
To your health,
Howard Schubiner, MD