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Do I need an X-ray or MRI before coming in? That one comes up constantly. It usually arrives dressed as an apology: “sorry, I haven’t had a scan yet, should I get one first?” No apology needed: you don’t generally need to have arranged imaging before an assessment can start. Our frequently asked questions page handles the logistics of a first visit. This post is about the decision itself, which is more interesting than it sounds, I promise.
Two things before we go any further, because this topic attracts a lot of overcorrection.
Nothing here is a reason to refuse imaging, cancel a scan, or ignore something your physician has ordered. And nobody at this clinic stands between you and an investigation. “Often unnecessary” and “not for you” are different sentences, and I only mean the first one.
What imaging is good at, and what it isn’t
An X-ray, ultrasound or MRI is very good at showing structure, and when structure is the question, that’s a genuinely useful thing to have.
What a picture can’t do on its own is tell you which finding (if any) is producing what you feel. That part is a clinical judgement, made by putting the image next to your history, your examination and your symptoms. A finding on a report is a measurement, not an explanation. Those are two different things, and keeping them apart is most of the skill.12
The question that actually decides it
Here’s the one worth remembering, because clinicians lean on it constantly and patients almost never hear it out loud:
Would the result change what happens next?
If a scan would change the plan (different treatment, different referral, different urgency), it’s worth doing. If the plan is the same either way, it’s usually delay and cost without a gain. Canadian recommendations put it in almost those terms. Routine imaging is often unnecessary when red flags are absent and the result wouldn’t change management.
“Often” and “usually” are load-bearing words in that sentence. Selective is not the same as never.3
Three examples, and they stay examples
One caveat before we get into these, and it genuinely matters: these describe common presentations, not you.
Uncomplicated low-back pain. This is the classic case for holding off. Canadian recommendations advise against routine imaging for low-back pain when red flags are absent, and staying active tends to matter more than a picture. That “when red flags are absent” clause is not decoration, by the way.
Non-traumatic shoulder pain. For many shoulder problems that came on without an injury, assessment, education and active rehabilitation are central options. Imaging often doesn’t change that starting point. Here’s what that also means, though: a shoulder can’t be labelled a rotator-cuff tear, a frozen shoulder or an impingement from symptoms alone. Not by an article, not by a symptom quiz, and not over the phone. Major trauma, marked weakness, systemic features or symptoms that aren’t improving can all change the pathway.
An ankle you’ve just rolled. There are validated decision rules clinicians use to decide who needs an X-ray after an acute ankle injury. They work well when they’re applied properly and completely. A shortened version is deliberately not printed here. A half-remembered rule is worse than no rule, and a rule applied to yourself on your own sofa isn’t the rule at all (it’s a guess wearing the rule’s jacket).
When imaging isn’t the question, it’s the priority
Some situations flip this entirely, and this is the section to read properly.
Seek prompt medical assessment, and emergency care where it fits, for a significant injury or major trauma, a suspected fracture or dislocation, neurological symptoms that are progressing, any change in bowel or bladder control or numbness around the saddle area, severe systemic illness or fever, a concern about cancer or infection, or anything involving your chest or your breathing.
In those situations imaging may be exactly what’s needed, and quickly. This post cannot rule any of them out, that list is not exhaustive, and it is not a self-screening tool. Please don’t use it as one.345
Who can send you for imaging in Ontario
This is a genuine question with a genuinely specific answer, and a blog post is the wrong place to improvise it.
Generally speaking, an Ontario physiotherapy assessment is expected to include relevant history and examination, your goals, a plan, reassessment, education, and referral where that’s needed. So “we’ll send you on if that’s the right call” is part of the standard, not a favour. Our physiotherapist works to that standard. And if your situation needs a physician, saying so is part of the job for both of us.6
A chiropractor is licensed in Ontario to send you for X-rays. Dr. Katie Sellars and Dr. Michaela McClure, our chiropractors, are both trained to assess you and make the decision about whether sending you for X-rays is necessary at any point during your care.
If you already have imaging
Bring what you’ve got. A report you had done two years ago for something else is often still useful context. And it saves everyone repeating work (me included).
Here’s the thing about old reports, though: a finding written on one doesn’t automatically explain what you’re feeling today. It’s information to weigh, not a verdict to carry around. I’ve met a lot of people who have been walking around for years believing a phrase from a 2014 report is the whole story about their back.12
So what should you actually do?
If you have any of the features in the red-flag section, get medical assessment, and start there, not here.
If your physician has already ordered imaging, get it.
And if you have a common musculoskeletal problem, no red flags, and you’re simply wondering whether to queue for a scan before booking anything? An assessment can help work out whether imaging is likely to change what happens next, which is a better use of the appointment than guesswork. That might be chiropractic care in Waterloo or physiotherapy in Waterloo, depending on what’s going on.17
Take care of yourselves,
Dr. Katie