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decision pointShould I have magnetic resonance imaging (MRI) for low back pain?

Consider the following when making your decision about having magnetic resonance imaging (MRI):

  • There is a good chance that your new (acute) low back pain will improve within 6 weeks-most cases do.
  • Avoid requesting costly imaging tests for acute low back pain. They usually provide no helpful early information. If you don't have signs of a serious medical condition (such as spinal infection or bone cancer), don't ask for or agree to imaging tests unless you have low back pain that has persisted through at least 4 weeks of nonsurgical treatment.
  • MRI is the best test for showing a herniated disc, soft-tissue damage, tumor, or infection.1 MRI also has the advantage of not using the ionizing radiation that the CT scan does.
  • Your doctor will probably wait to order an MRI for nerve-related symptoms that don't go away within at least 4 weeks, because these symptoms often go away on their own.
  • A technique called rapid MRI is probably no better than a standard X-ray for diagnosing the cause of back pain or deciding what treatment to use.2

What is low back pain, and what causes it?

Strained muscles and ligaments are the most common cause of low back pain and stiffness. This type of low back trouble generally goes away after 4 to 6 weeks of nonsurgical treatment.

Pressure on a spinal nerve can cause sciatica symptoms, including back pain and/or leg numbness, pain, tingling, weakness, or loss of reflexes. Causes of sciatica include:

  • Herniated disc, which usually gets better within a month or two.
  • Arthritis.
  • Spinal stenosis.

Other serious causes of back pain, such as infection, a tumor, or cancer, are rare. Only about 5% of low back pain cases are caused by serious disease or cause nerve-related problems that could be corrected with surgery. Imaging is helpful for diagnosing and planning treatment for these types of conditions.3

What are the risks of not treating low back pain?

We very often don't know what causes low back pain and, fortunately, it usually goes away on its own. But sometimes back pain is a sign of tight or weak muscles, poor posture, stress, or being overweight. It can also be a symptom of another condition, such as infection, a tumor, or a problem such as a herniated disc or spinal stenosis. If your back pain is caused by one or more of these problems and you don't take care of it, you could be in for more low back pain, decreased function, or other health problems in the future.

If your pain hasn't begun to subside after a couple of days of home treatment, see your doctor. After doing a health history and physical exam for low back pain, your doctor can recommend treatment, possibly including some physical therapy. You probably won't have any imaging tests unless your doctor sees signs of a serious condition or nerve problems.

What types of problems can magnetic resonance imaging (MRI) find?

An MRI is not a standard test for finding the cause of low back pain. As we age, we all develop changes in our spines that appear "abnormal" on an MRI , but in most people these changes don't cause symptoms.4 A complete medical history and physical exam are enough to diagnose and treat most low back pain.

Generally, an MRI is best used when your doctor suspects a specific problem after completing your medical history and physical exam. An MRI can:

  • Detect problems of the spinal discs, such as a ruptured disc. The test will also help determine whether a disc is pressing on a nerve.
  • Detect areas of the spinal canal that are abnormally narrowed (spinal stenosis).
  • Detect tumors of the spinal cord. The tumors that most commonly spread to the spine include those from prostate, breast, or lung cancer.
  • Further evaluate areas of joint inflammation (arthritis) or abnormal bone loss discovered during an X-ray test or a bone scan.
  • Locate areas of the spinal cord that are not receiving an adequate blood supply.
  • Detect areas of infection within the outermost layer of the spine and the spinal cord.
  • Detect areas of nerve damage in the spinal cord caused by trauma or disease, such as multiple sclerosis.
  • Evaluate spinal problems that have been present since birth (congenital).

For an idea of one type of problem an MRI can help identify, see MRI images of the lumbar spine .

MRI alone may not accurately show the source of your pain. Over time, we all develop changes in our spines that appear "abnormal" on an MRI, though these changes don't necessarily cause symptoms.4 Before you make a decision to have a surgery, it is important that your symptoms, physical examination, and imaging studies all point to the same source of back or leg pain.

If you need more information, see the topic Low Back Pain.

Your choices are:

  • Have magnetic resonance imaging (MRI).
  • Don't have magnetic resonance imaging (MRI).

The decision about whether to have an MRI takes into account your personal feelings and the medical facts.

Deciding about having an MRI
Reasons to have an MRI Reasons not to have an MRI
  • You are looking for the cause of severe, persistent sciatica (causing severe pain, numbness, tingling, weakness, or loss of reflexes in your leg).
  • Your doctor suspects that you may have some other problem (such as spinal infection or cancer) that is causing your symptoms.
  • You have severe, persistent, and disabling back or leg symptoms, so continued non-surgical treatment may not be a reasonable option.
  • Your doctor is planning surgery for a herniated disc and needs to see the disc clearly. For more information, see:
    Should I have surgery for a herniated disc?

Are there other reasons you might want to have an MRI?

  • You have not tried at least 4 weeks of nonsurgical treatment (including ice, exercises, and monitoring your body mechanics).
  • Your health history and physical examination revealed no signs of disease or nerve problems.
  • You have pain but are not disabled by it, and are learning to manage your back pain by strengthening your abdomen and back muscles and using home treatment measures.
  • Other imaging tests provide as accurate a screening for your particular situation as MRI does and are less expensive.
  • You are not willing to have a surgical procedure.

Are there other reasons you might not want to have an MRI?

These personal stories may help you make your decision.

Use this worksheet to help you make your decision. After completing it, you should have a better idea of how you feel about whether you should have magnetic resonance imaging (MRI). Discuss the worksheet with your health professional.

Circle the answer that best applies to you.

I have already had a thorough physical exam. Yes No Unsure
I have tried ice, exercises, and healthy back practices for at least 4 weeks. Yes No NA*
I have severe, disabling sciatica symptoms, and MRI results would help me make treatment decisions. Yes No Unsure
My doctor wants to check me for infection or cancer. Yes No Unsure
I am planning on having disc surgery, and the MRI results are needed for surgery planning. Yes No Unsure
Another imaging test can provide the information my doctor needs at less cost. Yes No Unsure
I have the financial resources or health insurance coverage to cover the cost of an MRI. Yes No Unsure

*NA = Not applicable

Use the following space to list any other important concerns you have about this decision.






What is your overall impression?

Your answers in the above worksheet are meant to give you a general idea of where you stand on this decision. You may have one overriding reason to have or not have an MRI to learn more about your low back pain.

Check the box below that represents your overall impression about your decision.

Leaning toward having an MRI


Leaning toward NOT having an MRI

  • Low Back Pain
  • Magnetic Resonance Imaging (MRI) of the Spine


  1. Carragee EJ, Hannibal M (2004). Diagnostic evaluation of low back pain. Orthopedic Clinics of North America, 35(2004): 7–16.

  2. Jarvik JG, et al. (2003). Rapid magnetic resonance imaging vs. radiographs for patients with low back pain: A randomized controlled trial. JAMA, 289(21): 2810–2818.

  3. Jarvik JG, Deyo RA (2002). Diagnostic evaluation of low back pain with emphasis on imaging. Annals of Internal Medicine, 137(7): 586–597.

  4. Borenstein DG, et al. (2001). The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects. Journal of Bone and Joint Surgery, 83-A(9): 1306–1311.

Associate Editor Tracy Landauer
Specialist Medical Reviewer Robert B. Keller, MD - Orthopedics
Last Updated February 3, 2010

WebMD Medical Reference from Healthwise

Last Updated: February 03, 2010
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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