Do I need an MRI for low back pain?

MRI Scan

MRI Scan

When Do I Need An MRI for Low Back Pain?

I had another patient tell me on the phone they are waiting to start physical therapy until they get an MRI, because “that way you’ll know what to treat.” I see the logic in this patient’s thinking. It makes sense. How could we possibly know what we are treating until we have an image of what is going on? In her mind, an MRI would provide that image to help guide my treatment so I can “fix” her condition.

What Does an X-Ray or MRI Image Show?

The reality is: X-ray and MRI imaging doesn’t tell the whole story. MRI images don’t tell us or any doctor “how” your low back pain started. MRI images don’t tell us “why” you have low back pain. When you get your MRI report back with statements like degenerative disc disease or degenerative joint disease, facet joint arthropathy, or spinal stenosis. You won’t know how commonly those conditions are found even in people without low back pain. In order to treat your condition, we need to know “how” and “why”.

Here is an article was written in 2011 about the new guidelines for primary care doctors regarding the management of low back pain. In the article, they talk about the high cost of getting the images and how they rarely help with managing low back pain. One of the more shocking admissions was how often getting an MRI for low back pain led to “unnecessary interventions” like injections and surgery.

This knowledge should give hope to low back pain sufferers frightened that surgery is going to be their only option. More and more evidence is demonstrating the best treatment for over 90% of all low back pain is exercise.

Check out how at Preferred Physical Therapy we can help you resolve your back pain:

When is it Time For an MRI?

To better help us (both providers and the public) understand how to triage low back pain cases that would need an MRI from those that don’t need an MRI, An article posted in 2006 divides low back pain into 2 categories.

  • 1) Specific Low Back Pain - symptoms caused by specific tissue breakdowns such as herniated nuclei pulpusi, infection, osteoporisis, rheumatoid arthritis, fracture, or tumor. This constituted less than 10% of all cases in the US.
  • 2) Non-Specific Low Back Pain - symptoms without a clear specific cause. This constituted more than 90% of all cases in the US.

It is a good time to get an MRI to rule out specific low back pain conditions. Providers must be able to decide based on the history and physical examination of the patient if there are any “Red Flag Conditions” that would suggest an MRI be the next appropriate next step.

These “Red Flag Conditions” are:

  • Non-mechanical pain (pain is not related to the time of day or type of activity)
  • Inclusion of Thoracic Spine Pain
  • Previous history of carcinoma, steroids, or HIV
  • Generally feeling “unwell”
  • Unexplained or unplanned weight loss
  • Widespread neurological symptoms
  • Structural spinal deformity
  • Younger than 20 and or older than 55 years of age

Another consideration for MRI imaging is the presence of nerve root problems. These symptoms include:

  • Pain down one leg more intense than pain in the low back
  • Pain radiating down to the foot or toes
  • Numbness or decreased sensation in one leg different than the other
  • Straight leg raise test causes more pain on one leg than the other
  • Pinching or compression on a single nerve root usually from a disc bulge, narrowing of the canal space where the nerve root exits or the presence of a tumor (very rare, only 0.3% of cases)

Neurological symptoms are considered “yellow flag” symptoms and are less likely to require an MRI when your low back pain improves or gets worse with specific movements

If I have Non-Specific Low Back Pain, What do I do Now?

The recommended course of treatment includes getting an assessment from a specialist who treats low back pain and can assess your unique movement habits, identify restrictions in your joints, and evaluate your core strength. This information is better at describing “why” and “how” you have low back pain. The assessment from a specialist provider will help turn “non-specific” low back pain into a specific treatment plan.

This next part gets a little tricky because it’s easier than ever to jump over to youtube and look for “exercises for low back pain”. While it’s possible many of those exercises will help and will be better than doing nothing. Don’t make the mistake several people make in thinking that just because your low back pain is labeled “non-specific” doesn’t mean the treatment should also be “non-specific”.

Doing “all the exercises” can make your pain worse, delay recovery, and waste a lot of time. If you’ve been suffering for a few months or if your episodes of low back pain are occurring more often and lasting longer… Would it be such a bad idea to have a specialist evaluate your low back pain?

Do you have chronic low back pain? Check out this at-home low back pain program. Click here


The short answer is we don’t need an MRI or an x-ray to know what is going on. There is no correlation between what is found in the MRI to what is causing your pain with 90% of the population who suffer from “non-specific” low back pain.

One reason low back pain sufferers feel compelled to get an MRI is the need to justify the amount of pain they are in based on the diagnosis. As if being told they have “non-specific” low back pain is the same as being told the pain they are feeling is “all in your head”. When you’re in pain, being told it’s all in your head is hurtful.

Also hurtful to many patients is coming back with the MRI report and seeing “mild” describing all the findings. Many are left frustrated and say to me, “how can it be mild when my back hurts so bad!” This is because there is no correlation between the findings of an MRI and the amount of back pain you have. The image reports on the condition of your spine which is highly subjective by the radiologist and highly predictable given your age and background.

An MRI shows you an image of your spine, joints, discs, and nerves and is only indicated for “specific low back pain” conditions such as cancer or severe nerve involvement are suspected.


Nick Hunter, PT, DPT

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