Low Back Pain - When do I need an MRI?
Today’s topic is another common complaint I see in primary care - low back pain. I see back problems in patients of all ages and activity levels. Sometimes patients have to reach out for an appointment within hours of back pain starting because of its severity, while others seek me out because it’s been weeks without improvement. In many cases, patients are wondering about getting imaging, like an MRI. I understand the impulse - when something is very painful, the body is telling the brain something is wrong. Therefore, why not get an MRI to see what it is and fix it!?
The majority of the time however, with acute onset low back pain, an MRI is not indicated. The main purpose of getting an MRI of the lumbar spine is really to prepare for an invasive intervention - either spinal injections or surgery. Most patients presenting with a day to a few weeks of back pain are not at the point of considering invasive procedures. Rather, it makes more sense to start with lower risk, non-invasive treatment such as anti-inflammatory medication and physical therapy. In the absence of concerning neurologic symptoms, any finding on an MRI (degenerative discs or other signs of arthritis, herniated discs, spinal stenosis etc) will first be treated with at least 6 weeks of physical therapy before considering any surgical treatment. This is why physicians typically don’t recommend an MRI at the first evaluation for back pain. Regardless of what it shows, the recommendation will be to start with conservative treatment including physical therapy. Most of the time back pain will resolve with these treatments over several weeks to a few months. Only if back pain persists after the typical treatment are we ready to move forward with imaging and likely referral to either a pain management specialist for injections or a spinal surgeon.
Sometimes patients are frustrated when they seek an evaluation for back pain and it doesn’t include an MRI. I hope that the take away from my post is not to avoid seeing your primary care if you are bothered by your back, but rather to help temper this expectation of imaging. Many times in medicine a history and physical exam are better for diagnosis and treatment than imaging. This is true for low back pain. An MRI of the low back is just as likely to show abnormal findings in someone without back pain as it is in someone that has back pain. The key is to order the MRI on the right patient at the right time, and see if the location and type of abnormalities on the image match up with the reported pain and physical exam findings. When this happens, a patient is much more likely to benefit from an intervention like injections or surgery.
But it is important to get checked out by your primary care if you are having concerns - this is easy with direct access primary care, whether it’s the first day of pain or the 3rd week of pain! My patients are able to send me an email, a text, or a portal message to let me know what’s going on, arrange an appointment within a day or two for an exam, and together we can discuss when it’s the right time for an MRI and how to get you feeling better in the interim!
