Evidence based

Back Pain: When Is MRI Imaging Necessary?

Last updated: 
April 6, 2020
Abby Perry
Researcher and author
Dr. Juliana Bruner, DPT
Researcher and author, Physical Therapist

If you’re suffering from back pain, you may be wondering if imaging tests like an X-ray, computed tomography scan (CT scan), or magnetic resonance imaging (MRI) can provide insight into the source of your pain. But scans can be expensive and take time to schedule. So when should you consider a scan like a spine MRI and when should you try other solutions?

In this article, we’ll walk you through the ways in which back pain is typically diagnosed, and help you understand when you should consider an MRI along with how to interpret the results of an imaging test.

How Is Back Pain Usually Diagnosed?

Back pain is usually diagnosed through physical examination, including physical tests that assess any neurological (nerve-related) components that might be causing or contributing to back pain. These tests seek to elicit momentary pain through certain movements that indicate whether a nerve is irritated “by a mechanical cause, usually (having to do with) the vertebral bones or herniated disc” (1). These tests can also help your healthcare provider identify sciatica, a radicular (radiating) form of pain often originating in the lower back and traveling down one leg (2).

Lower back physical exams include: 

  • Straight leg test: If you have back pain that radiates down your leg, your doctor may try a straight leg test. You’ll lie down on your back and relax your legs. Your healthcare provider will cup your foot and gently raise your leg. If your pain is due to nerve root irritation, you’ll likely experience pain when your leg is between a 30 and 60 degree angle.
  • Stork test: your healthcare practitioner will ask you to stand up straight. When you feel well balanced, you’ll lift one leg and place your foot against the inside knee of your standing leg. You’ll then place your hands on your hips, and then rise up and balance on the ball of your foot (3). A positive stork test can indicate a problem with your sacroiliac joint.
  • Adams forward-bending test: Stand with your feet together. Bend over and let your head and hands hang toward the floor. If your doctor notices asymmetry in your torso or shoulder blades, this could be indicative of scoliosis (4).

Summary

Lower back pain is normally diagnosed through a physical examination that looks for structural problems or nerve damage. As part of the exam, your doctor may ask you to complete certain motions and report how those motions affect your pain.

Treatments to Explore Prior to Imaging

Unless the results of your physical examination point to deeper issues like structural problems or major injuries, your doctor will likely recommend some first-line treatments to try out before considering an imaging test.

Conservative Medication

Most cases of lower back pain resolve themselves within a few weeks and can be treated through over-the-counter pain medications such as non-steroidal anti-inflammatory drugs (NSAIDs), which include ibuprofen (Advil) and naproxen (Aleve). NSAIDs are typically safe when taken in proper dosages. However, heart problems and stomach pain can be side effects of NSAIDs, so if you have any family history of cardiovascular or gastrointestinal conditions, speak to your doctor about the safest over-the-counter medication choice for you.

If your pain is more severe, you may be a candidate for stronger pain medications like prescription-strength NSAIDs or muscle relaxants. Talk to your doctor about what medications to consider if your pain interferes with your ability to sleep or go about routine tasks.

At-Home Physical Therapy

Simple, at-home exercises can provide a great deal of relief to people suffering from back pain. Exercises include:

  • Hamstring stretch: Lie on the floor with your legs out in front of you. Lift one leg and pull your thigh toward your chest. Try to achieve a 90-degree angle. Straighten your knee until you feel a stretch – not pain, just a stretch – in the back of the thigh. Hold for 60 seconds. Lower slowly, then repeat with the opposite leg (5).
  • Cat exercise: Balance on your hands and knees on the floor. Straighten your spine. Keep your hands shoulder-width apart and elbows out. Keep your knees hip-width apart and feet relaxed with the tops of your toes resting on the ground. Breathe in slowly as you arch your back up toward the sky. Then breathe out slowly as you release your back and abdomen and let them dip down to the ground. Return to a neutral position then repeat the arch and dip three to five times (6).
  • Cobra pose: Lie flat on the floor on your stomach. Place your hands beneath your shoulders with your fingers spread wide. Point your toes so that the tops of your feet rest on the floor, like in the cat exercise. Ground your hips as firmly as you can, then slowly lift your chest while drawing your shoulder blades toward each other. Slowly lower by bending your arms until your chin touches the floor (7).
  • Single Leg Pull: Lie back on the floor with your right leg outstretched and the left leg bent with its foot flat on the floor and knee pointed toward the ceiling. With your left hand, pull your left knee toward your chest in a slow, even motion. Focus on keeping your lower back and right knee pressed down to the floor. Hold for five seconds. Slowly lower your leg and slowly take a deep breath in and out. Repeat four more times. Switch your lg position and repeat five times on the alternating side.

Cold Therapy

Cold therapy, which can be applied at home through the use of a homemade ice pack, bag of peas wrapped in a towel, or cold gel pack purchased at a pharmacy or online, may provide some relief. Protect your skin by wrapping the cold object in a thin towel or by wearing a cotton T-shirt. Apply the cold object to the painful area in 15-20 minute increments. This therapy will reduce swelling and have a numbing effect (8).

Heat Therapy

Heat therapy can reduce pain by increasing blood flow to the affected area, which can be especially helpful in cases of muscle tightness. You can wear a heat wrap, apply a heating pad, or take a hot shower or bath in order to practice heat therapy at home. If you’re applying a hot object such as a wrap or pad, take care to ensure that your skin is protected by a cover, towel, or T-shirt (9).

Massage Therapy

Massage can also relieve back pain. Harvard Health lists the following types of massage as common options for relief (10):

  • Acupressure (shiatsu): The masseuse applies deep pressure with their fingers along the meridians, or “energy channels,” of the body. 
  • Cranial-sacral therapy: Theoretically uses light touch to recalibrate cerebrospinal fluid.
  • Deep-tissue massage: This firm, intense massage aims to relieve major muscle tension and relax connective tissues.
  • Neuromuscular therapy: Seeks to alleviate both acute and chronic pain.
  • Myofascial release: Aims to release tension in the connective tissue surrounding the muscles.
  • Sports massage: Massage specifically designed to help athletes.
  • Swedish massage: Employs long strokes with pressure according to the client’s preference, along with kneading the muscles.

Alternative Treatments

Several alternative treatments show positive therapeutic effects in some cases of back pain. These include:

  • Acupuncture: thin needles are inserted into the body at various intentional points in order to relieve pain and promote wellness (11, 12). 
  • Spinal manipulation: typically performed by a chiropractor, spinal manipulation attempts to restore proper spinal alignment. It may relieve lower back pain and restore lost function (13).

Yoga: While yoga can alleviate back pain, it can also cause back injuries if not practiced properly. Talk to your healthcare provider first if you’re suffering from back pain. If you’re cleared to practice yoga, focus on proper posture and slow movements. When practiced correctly, yoga can stretch and strengthen the muscles around your spine (14).

Summary

A few weeks of medication and physical therapy is typically enough to resolve most cases of lower back pain. Other conservative treatment options include heat therapy, cold therapy, and massage therapy.

When to Consider an MRI

If your back pain persists for six weeks and does not respond to pain relievers or physical therapy, then an MRI scan of the lumbar spine may be appropriate (15). MRIs are frequently overused, so don’t rush to imaging if your back pain is an isolated ailment. If you have certain red flag conditions such as malignancies, fractures, cauda equina syndrome, or infections, do not wait six weeks or attempt to alleviate your pain with over-the-counter medications or physical therapy (16). Instead, consult a doctor immediately. They’ll help you determine whether to undergo imaging earlier on.

If your doctor recommends an MRI, you may want to ask a few questions, such as:

  • How long will I be in the MRI machine?
  • Will earplugs be provided?
  • What’s the name of the radiologist who will read the results?
  • Will the MRI be with or without contrast dye? If with a contrast dye, what are the chances of an allergic reaction?

Summary

MRIs are overused, so don’t rush to imaging. However, if your back problems last for six weeks without responding to over-the-counter pain relievers or physical therapy, or if you have a history of cancer, fractures, or infections, speak to a doctor as soon as possible.

What Types of Back Pain Is an MRI Useful for Assessing?

MRIs are most useful for assessing neuropathic back pain, which is back pain that arises from a nerve-related cause. Possible nerve-related causes of back pain include:

  • Disc herniations: Disc herniations occur when inner-cartilage breaks through a crack in the disc’s outer layer. This can be quite painful if the discs press on nearby nerves. Herniated discs are also referred to as slipped discs or ruptured discs. They occur most commonly in people between 30 and 50 years old, and are twice as common in men when compared to women (17).
  • Bulging discs: When discs become dehydrated and cartilage stiffens (this often happens later in life), bulging discs can occur. Unlike herniated discs, bulging discs only affect the outer layer of disc cartilage. Bulging discs can cause nerve root compression as well as radicular pain. While bulging discs are distinct from herniated discs, hernias can occur in bulging discs (18). 
  • Spondylolisthesis: Typically occurring after a break or fracture, spondylolisthesis refers to one vertebra slipping out of position and becoming displaced over the vertebra next to it (19). This can result in nerve compression.

Pinched nerve: This extremely common condition occurs when muscle, bone, cartilage, or muscle tissue compresses a nerve. Injury, arthritis, stress, sports, and obesity can all cause pinched nerves (20).

Summary

MRIs can be useful in diagnosing back pain that arises from neurological conditions such as disc herniations, bulging discs, spondylolisthesis, or pinched nerves.

How Accurate Are MRI Results and Associated Diagnoses for Lower Back Pain?

MRIs effectively identify disc and vertebral issues. However, while these issues can cause back pain, they don’t always do so. More simply, you can have a herniated disc but not experience any lower back pain. And you could have lower back pain with no disc or vertebrae problems (21, 22).

Overall, there’s not a strong association between MRI results, problems discovered through MRIs, and lower back pain. Your doctor should make an assessment based on all of the available information, including family history and physical examinations. The MRI imaging should just be one component, not the cornerstone, of forming a diagnosis and treatment plan for back pain relief.

Summary

While MRIs can detect disc and vertebral issues, and associated nerve pain, the presence of such issues doesn’t mean that they’re the cause of your lower back pain. MRIs shouldn’t be considered a cornerstone for building a diagnosis and treatment plan for lower back pain.

What Do I Need to Remember?

While MRI imaging can be useful for finding disc issues and resulting nerve pressure that may cause back pain, MRIs are often overused as a diagnostic metric. They can sometimes lead to an incorrect diagnosis. There are a number of different factors that can cause back pain, most of which will not show up on MRI results. The research shows that there isn’t an extremely strong correlation between MRI imaging results and back pain (23).

Rather than rushing to MRI imaging as a first-line treatment, try conservative responses such as over-the-counter pain relievers, at-home remedies, and physical therapy first. In cases of persistent pain lasting six weeks or more that doesn’t respond to conservative treatment, or if certain red flags accompany your case like malignancies (or history of cancer) or fractures, an MRI may be necessary and helpful.

The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

Research Citations

Researched, written, and reviewed by:
Abby Perry
Researcher and author
Abby Perry is a freelance writer who brings over ten years of experience with work published in Entropy, Fathom Magazine, and Sojourners. She lives in the great state of Texas with her husband and two sons.
Read full bio
Dr. Juliana Bruner, DPT
Researcher and author, Physical Therapist
Dr. Bruner is a physical therapist who is highly trained and skilled in helping people overcome their physical ailments to live the best life they can. She is also a writer who enjoys spreading knowledge about various topics in the PT and healthcare industry.
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This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of board-certified physical therapists, physicians, and surgeons strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.