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Do I need an Xray?

Every kid has (at least once!) wished for superpowers…from flying to super strength to x-ray vision! As a physiotherapist, I too used to wish for X-ray vision (or even better – MRI vision!!) in an effort to save my patient from making an extra trip to the doctor’s office as well as actually “seeing” what was going on inside.

Humans have always had a desire to look inside the human body – with the first recorded human dissection occurring in 3rd Century BC for Ancient Greek physicians to learn anatomy (1). It wasn’t until x-rays were discovered, back in 1895 by Wilhelm Roentgen, that we could see inside the human body via non-invasive methods (2). In fact, the first x-ray ever taken was that of Roentgen’s wife’s hand (2)!

Pic 1: The first x-ray


Pic 2: Lumbar spine & pelvis

X-rays are a powerful, effective, and non-invasive tool best utilized to visualize bones & joints. They are used to look for and monitor fractures, osteoarthritis, disc degeneration, bone growths, and certain types of cancers. Note that they’re not very effective at visualizing softer tissue (such as ligaments, tendons, or muscles).

X-rays are also relatively cheap (only costing the medical system approximately $15-20 per image) compared to MRI’s (approx. $900-2000 per region) (3).


But as Stan Lee penned in the Spider-Man comic “with great power, there must also come great responsibility” (4). Super x-ray vision (or at least in reality – x-rays used for the purposes of diagnostic imaging) does not come risk free. Exposure to repeated radiation over time has been associated with a higher risk of cancer (5). One study found an increased risk of breast and thyroid cancer in patients with scoliosis who received 10-12 full spinal radiographs over a typical lifespan (5).

Keep in mind, however, that typical radiation exposure from a single x-ray is very small. The exposure dosage ranges from approximately 0.001mSv (for an arm or leg) up to 1.5mSv (for the lumbar spine) (6).

CT Scans have even greater levels of exposure (ranging from approximately 6-16mSv (6)) as they are essentially multiple x-ray/radiographs combined by the power of computers to create a 3D image.

When comparing numbers, it is important to recognize that we are always receiving exposure to radiation:

  • from the stars (aka. “cosmic” radiation – amount of exposure depends on your elevation, with higher elevations receiving more exposure than at sea-level. For example, Vancouverites on average receive 1.3mSv/year vs those high-riders up in Whitehorse who receive 1.9mSv/year) (7)

  • from the earth’s crust (which contains uranium and thorium) (8)

  • and even from our food (for example, brazil nuts contain radium-226)! (8)

Over a lifetime, exposure to both natural radiation sources as well as medical sources can add up. The Canadian Nuclear Safety Commission estimates the lowest exposure that has been observed to correlate with increased risk of cancer as 100mSv and recommends no more than 1mSv per year (9).

I have lower back pain, should I get an x-ray?

Approximately 90-95% of people with lower back pain (LBP) tend to improve within 4-8 weeks using a combination of heat, non-steroidal anti-inflammatory drugs (NSAIDs), gentle/general activity, and physiotherapy (10, 11).

Another 5-10% of those with LBP suffer from radicular pain (which is lower back pain due to the irritation and/or compression of nerves – eg sciatica) (10). NSAIDs likely may not be as effective for this group, but positive outcomes are still generally possible with physiotherapy.

The thankfully rare and last 1% are those with “Red Flags” which include serious conditions such as cancer, vertebral fractures, spinal infections, and cauda equina syndrome (10, 11). These disorders require immediate diagnostic imaging and interventions. Also included in the “Red Flags” category are those with inflammatory LBP (or axial spondyloarthropathies, such as Ankylosing Spondylitis) (12). While not as urgent as the other “Red Flags”, they do require a very different approach in physiotherapy treatment (10).

It is important to talk to your doctor and/or physiotherapist about which category your back pain fits. In the majority of cases however, it is not necessary to get an x-ray right away. Researchers have found that getting early diagnostic imaging does not lead to better/faster outcomes and actually has been associated with longer time off work and increased rates of surgery (11,13)!

I have a really high level of pain; doesn’t this mean that something serious has occurred?

Not always…because pain is weird. The intensity of pain experienced does NOT always relate to the amount of tissue damage (14). What most of us expect is the greater the amount of tissue damage (ie knife to belly), the greater the pain levels (ie 10 or 11 out of 10 pain!!).

But pain is bizarre. It doesn’t always “match up”. An extreme example is that of a World War II veteran who discovered a bullet in his neck 60 years after the fact, thanks to a routine chest x-ray (14). Another example is that of a mother running back into a burning building to save her child and not feeling any pain despite the 2nd and 3rd degrees burns (14). You may be thinking this is a once-in-a-lifetime kind of thing. But this “mismatch” can occur in your daily life too…

For example, a papercut definitely stings (giving it at least an 8-9/10!), but technically speaking – it’s very low on the level of tissue damage (heck, it’s not even bleeding!) (14). Or have you ever wakened with a new bruise and wondered how it got there? There’s usually no (or minimal) pain, but you can clearly see that damage has been done (from the burst blood vessels under the skin).

This is because pain relies on more than just biology. It’s there to protect you – and is based on how much the brain thinks you are in DANGER (14). It can be adjusted by your mood, stress levels, quality of sleep, and other general lifestyle factors (14,15).

Long story short, pain is weird. A high level of pain doesn’t always mean lots of tissue damage and a lot of tissue damage doesn’t always mean pain. For example, researchers looked at 3,110 CT and MRI scans of PAIN-FREE people and found high percentages of:

  • degenerative disc disease (ranging from 37% of 20-year-olds up to 96% of 80-year-olds) (16)

  • disc bulges (30% of 20yo up to 84% of 80yo) (16)

  • spondylolisthesis (3% of 20 yo up to 50% of 80 yo) (16)

These types of “degenerative” changes are just a NORMAL part of aging and are typically insignificant (15).

But it’s been more than 6 weeks, and I’m still struggling with lower back pain despite doing all of my exercises…

It is a good idea to discuss pursuing further diagnostic imaging with your physiotherapist or doctor if:

  • your lower back pain is not improving and/or is worsening after 6-8wks despite trying conservative treatments (12,17,18).

OR if you have any of the following symptoms along with your LBP (15):

  • numbness in your genitals OR where you wipe yourself after using the toilet

  • loss of bladder or bowel control, change in sexual functioning

  • increased clumsiness of your legs or a feeling of unsteadiness with standing/walking

  • generally feeling unwell, fatigued, unexplained weight loss, and/or fever


We must not throw the baby out with the bathwater… X-rays are incredibly powerful and useful tools. The key is to use them wisely, when we need them, and limit our lifetime exposure to radiation as much as possible. If you have more questions about whether x-rays may be the right next step for you, talk to your local medical professional.

If you have more questions about back pain, feel free to book a telehealth appointment with any of us at InReach Physiotherapy!

By: Susan Herdman, Registered Physiotherapist

Book a telephysio / online physio / virtual physio / video physiotherapy appointment with a registered physiotherapist in British Columbia. InReach Online Physio services communities in northern and rural BC, such as Masset, Queen Charlotte, Fraser Lake, Fort Nelson, Fort St James, Dease Lake, Fort St John, Dawson Creek, the Gulf Islands, and more! InReach also collaborates with Northern Health, Island Health and the First Nations Health Authority.


1) Ghosh SK. (2015) Human cadaveric dissection: a historical account from ancient Greece to the modern era. Anat Cell Biol 2015;48:153-169. Accessed Nov 8/2021:

2) Science Learning Hub (2007 July 21). Developments in medical imaging – timeline: 8 November 1895 – X-rays discovered. Accessed Nov 8/2021:

3) Canada Diagnostic Centres (2021). Fee Schedule. Accessed Nov 9/2021:

4) Subtropic Productions LLC – Deis R (2012 July 5). “With great power comes great responsibility”: The evolution of the pithy proverb. Accessed Nov 8/2021:

5) Levy AR, Goldberg MS, Mayo NE, Hanley JA, & Poitras B (1996 July 1). Reducing the lifetime risk of cancer from spinal radiographs among people with adolescent idiopathic scoliosis. Spine (Phila Pa 1976);21(13):1540-8. doi: 10.1097/00007632-199607010-00011. Accessed Nov 8/2021:

6) Harvard Health Publishing (2021 Sept 30). Cancer: Radiation risk from medical imaging. Accessed Nov 8/2021:

7) Canadian Nuclear Safety Commission (2020 Dec 22). Radiation: Radiation doses. Accessed Nov 8/2021:

8) Canadian Nuclear Safety Commission (2019 Sept 12). Radiation: Types and sources of radiation. Accessed Nov 8/2021:

9) Canadian Nuclear Safety Commission (2015 Apr 16). Health Studies: Linear-Non-Threshold Model. Accessed Nov 8/2021:

10) Traeger A, Buchbinder R, Harris I, & Maher C (2017). Diagnosis and management of low-back pain in primary care. CMAJ November 13; 189:E1386-95. doi: 10.1503/cmaj.170527 Accessed Nov 8/2021:

11) Choosing Wisely Canada (2017 May). Imaging tests for Low Back Pain: When you need them – and when you don’t. Accessed Nov 9/2021:

12) Millán Ortuondo E, Cabrera Zubizarreta A, Muñiz Saitua J, Sola Sarabia C, & Zubia Arratibel J (2014 Jan-Feb). Indicaciones de la resonancia magnética en la lumbalgia de adultos [Indications for magnetic resonance imaging for low back pain in adults]. Rev Calid Asist;29(1):51-7. Spanish. doi: 10.1016/j.cali.2013.10.004. Accessed Nov 9/2021:

13) Lemmers GPG, van Lankveld W, Westert GP, van der Wees PJ, & Staal JB (2019 May). Imaging versus no imaging for low back pain: a systematic review, measuring costs, healthcare utilization and absence from work. Eur Spine J; 28(5):937-950. doi: 10.1007/s00586-019-05918-1. Accessed Nov 9/2021:

14) Butler D & Moseley L (2013). Explain Pain - Section 1. NOI Group Publications. Adelaide, Australia. p 8-25

15) Macquarie University – Dept of Health Professions: Faculty of Medicine & Health Sciences. Understanding my low back pain and whether I need imaging. Accessed Nov 15/2021:

16) Brinjikji W et al (2015 Apr). Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol 36:811-816. Accessed Nov 8/2021:

17) Johnson SM & Shat LM (2019 Mar). Imaging of Acute Low Back Pain. Radiol Clin North Am;57(2):397-413. doi: 10.1016/j.rcl.2018.10.001. Accessed Nov 9/2021:

18) Srinivas SV, Deyo RA, & Berger ZD (2012 Julym9). Application of “less is more” to low back pain. Arch Intern Med;172(13):1016-20. doi: 10.1001/archinternmed.2012.1838. Accessed Nov 9/2021:


Pic 1: The first x-ray

Science Learning Hub (2007 July 21). The first x-ray. Accessed Nov 8/2021:

Pic 2: Lumbar spine & pelvis

Nevit Dilmen © (2011) Roentgenogram or Medical X-ray image. May not be to scale.


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