In a recent issue of the Journal of Orthopedic and Sports Physical Therapy, there is an article concerning the pros and cons of diagnostic imaging that I found fascinating and I want to share some of the highlights.
Diagnostic imaging from a musculoskeletal stand-point usually includes radiographs (“x-rays”), MRIs, and CT scans (“cat scans”). Each of these types of imaging can be useful tools in helping to confirm suspicion of an injured soft tissue or bone; however, the benefits of using imaging to find causes of low back pain can actually be little to none. Research in this area has found that imaging can expose people to unnecessary and dangerous amounts of radiation; it may not actually show the source of pain; and it can drive up health care costs because it often leads to further testing, follow-up appointments, and invasive procedures of limited or questionable benefit.
The fact is, low back pain can have many causes, and very few of them can be identified correctly with imaging. I hear you, you’re saying, “but if I have a herniated disc, and I have back pain, the MRI will detect it and then we’ll know for sure that’s the cause. Right?” Actually, no. The reality is that each type of diagnostic imaging gives you a really good look at your internal anatomy at one moment in time.
There was a recent study in the Journal of the American College of Radiology in which they took an MRI of 200 persons, age 60 years or older. Each person received a baseline MRI; which means at the time of the test, they had no symptoms of low back pain. They followed these people for 5 years, and if they ever had a return of back pain symptoms, they took another MRI. Of the people that went on to have severe low back pain within the 5 year period, 84% of them either had no change or they had improvement in their MRI findings. An even more amazing finding is that 90% of all the people in the study had some serious finding of pathology on their baseline MRI. These pathologies included disc protrusions or annular tearing (something that can lead to disc protrusion) and potential nerve root irritation; yet none of them had pain or any other symptoms at the time of the MRI.
One might make the conclusion that if a patient has an MRI and the findings are unremarkable, it will put the patient’s mind at ease to know nothing is seriously wrong. Studies concerning the psychological effects of routine imaging found that unremarkable results actually did not help alleviate patients’ fear and worry about back pain.
Oftentimes imaging is ordered without performing a thorough physical exam. I kind of think of it as taking a “short cut”; however, this is not necessarily a benefit for the patient, and can potentially cause them harm. Radiation exposure occurs with radiographs and CT scans. A feared consequence of excessive radiation exposure is an increased likelihood to develop cancer. In 2007, 2.2 million CT scans of the lumbar spine (low back) were performed in the US. This amount of radiation exposure to patients is projected to cause 1200 future cancers. Radiographs (x-rays) of the lumbar spine are found to cause radiation exposure that is 75 times higher than the average chest radiograph. This is concerning in women because there is no method for shielding the female gonads (reproductive organs). The amount of radiation the female gonads are exposed to during one lumbar radiograph is estimated to be the same as having a daily chest radiograph for several years! So if it isn’t absolutely necessary, you may want to pass on these tests.
Another con to overutilization of diagnostic imaging is the contribution it can make to the rise of healthcare costs. In 2005, total healthcare expenditure in the US for low back pain was $85.9 billion, and a large chunk of that was from imaging, invasive procedures such as injections and surgery, and hospital stays (usually after a surgery). Let’s face it, health care costs are huge, and even though your insurance company may foot the bill for diagnostic imaging, these tests and procedures are expensive, and overutilizing them will drive up costs for everyone in the long run. There was a study performed regarding Medicare beneficiaries from 1994 to 2004 in which they found the number of surgeries tripled for low back pain if an MRI was used early in the course of treatment versus a radiograph. Moreover, there was no improvement in outcome from these surgeries in the following year (a.k.a.--no decrease in back pain or increase in function). These surgeries are costly, as well as life-threatening to older adults, but not necessarily beneficial.
In 2004, a hospital in Seattle, WA was informed by a large insurance company that their costs for treating patients with low back pain far exceeded treatment costs in other local facilities. Many of the doctors in this hospital routinely ordered an MRI (and no, there was no financial incentive for them to do so). The hospital studied their approach toward patients with low back pain, and changed their system to implement an evidence-based protocol. This included attending physical therapy as an initial treatment. The rate of MRIs went down 10-15%, the cost per episode of care went down about $1000, the number of patients with chronic pain significantly reduced (so much that the hospital needed fewer staff in their chronic pain center), and only 6% of patients lost time from work.
It has been researched extensively and the vast majority of patients with low back pain do not need diagnostic imaging. The physical exam performed by a physical therapist or other healthcare practitioner should determine if imaging is needed.
If you have any other questions about imaging or physical exams to diagnose an injury, please email me at Erin@JointVenturesPT.com, or you can read the article I cited above.
Journal of Orthopaedic and Sports Physical Therapy, November 2011, volume 41, "Appropriate Use of diagnostic imaging in low back pain: a reminder that unnecessary imaging may do as much harm as good"