The Role of Diagnostic Imaging in Physiotherapy
September 10, 2018 4:04 pm
When we injure ourselves, the first thing we often wonder is “do I need an x-ray?” Sprained ankle, kinked neck, tennis elbow, rotator cuff injury – what types of injuries warrant further investigation? Is it necessary to see a Physician if imaging (ultrasound, x-ray, MRI, CT scan, etc.) is required?
The role of diagnostic imaging in rehabilitation is somewhat controversial, with most Clinicians having to balance the benefits of the imaging with the risks. Yes, the risks.
First off, we need to consider the radiation exposure. Different regions of the body have different sensitivities to radiation, and too much exposure can lead to serious and long term complications. X-rays and CT scans use radiation, whereas ultrasounds and MRIs do not. With this in mind, it’s important to minimize x-rays and CT scans unless it’s absolutely necessary.
In addition to the radiation exposure, we have to be respectful of the drain placed on the healthcare system when too many unnecessary images are requested. Part of the reason MRIs have such a long wait time is because there are many other people waiting for an MRI, which may not even be indicated. The Clinician ordering the imaging must make a very educated decision as to WHAT the imaging is looking for, WHICH type of image is most appropriate for making the diagnosis and WILL the results alter management. Answering these questions will significantly reduce the number of people on our wait lists for diagnostic imaging.
Third, and most importantly, there is the risk of too much information. I spend a lot of my time as a Physiotherapist educating clients about the fact that degenerative changes, in most cases, aren’t anything to worry about. In fact, most individuals over the age of 30 show evidence of degenerative changes on imaging, even if they don’t have any pain. Degenerative changes include rotator cuff tears (common in overhead athletes), osteoarthritis (often considered “wear and tear” of the joints that are under load – for example gravity or high impact sports) or degenerative disk disease of the spine (once again, gravity is heavy!) So….how is this risky? In many cases, the diagnostic imaging findings of degenerative changes are completely unrelated to your current symptoms! If a treatment plan is developed based entirely on the imaging findings, it may be a completely inadequate treatment plan that focuses on the wrong structures and is essentially ineffective. Also, the knowledge of the unrelated structural changes may cause some people to fixate on the imaging findings rather than functional improvement. In most cases, improvements seen in function and pain are not correlated to changes in structure on follow-up imaging. For example, if a rotator cuff tear is initially diagnosed on ultrasound, it will likely still be visible months later even if full pain free movement, function and strength have returned. Our bodies have fantastic capabilities to adapt and prevail against injury!
With all of that said, diagnostic imaging still has an important role to identify major injuries. If the injury is not responding to conservative management and a more invasive treatment is being considered, diagnostic imaging will help guide the treatment plan. X-rays can identify fractures and dislocations, as well as bony abnormalities. More subtle bony injuries such as stress fractures or fractures in complex regions such as the hand or foot are often hard to see on X-ray, which leads to a false negative. In these cases, we may decide to immobilize the area anyways and treat the bone as if it’s been broken, then follow up with a second x-ray in 2 weeks when we would expect to see visible signs of healing on the image. Ultrasounds are very good at detecting muscle and tendon tears, tendonitis and any injury of the soft tissue. Ultrasounds have the benefit of being able to visualize the tissue in real time, which allows a more accurate and dynamic assessment of the soft tissue. One of the downsides to ultrasounds is that they are heavily dependent on the skill of the technician and the Radiologist in identifying the injured areas. MRIs are indicated to visualise the anatomy and areas of edema (swelling) in greater detail, which is useful in diagnosing complex injuries. An MRI would be able to visualize the stress fracture that was missed on x-ray because it can see areas of swelling within the bone. The downsides to an MRI are the cost and the wait times, in which case the urgency of the information needs to be considered. It’s possible to pay for a private MRI, which will expedite the process significantly. CT scans are also used for a more detailed analysis of the anatomy, but have a particular strength in identifying bony abnormalities that were missed on x-ray. CT scans are often used in screening areas of the body that have sustained major trauma.
Until recently, Physicians were the only ones who were able to order diagnostic imaging. Now, more and more Physiotherapists are gaining the appropriate credentials to allow them to order x-rays, ultrasounds and MRIs. This helps speed up the process and reduces the need for additional Doctor visits. Physiotherapists who are registered to order imaging are trained in the decision making process to determine if imaging is, in fact, necessary. This means that they will form a clinical diagnosis and then decide if further information is necessary or helpful to the course of treatment. If you are uncertain about whether imaging is required for your injury, it’s best to have a Physiotherapist assess the injury and either order the appropriate imaging if indicated, or send a detailed letter to your Family Physician outlining the proposed diagnosis and appropriate management strategy. Whatever your Clinician’s decision is, they are always acting in your best interest to help you recover from your injuries as fast as possible!
MScPT, BScKin, CAFCI, FCAMPT,
Dry Needling Certified