“Do I need a scan?”
Diagnostic imaging is a fantastic and commonly utilised tool in healthcare. Imaging allows clinicians to get detailed pictures of structures in our body to make or confirm a diagnosis, or to rule out serious pathology. There are many forms of imaging currently available (X-Ray, US, MRI, CT scan, PET, Bone Densitometry etc.) which all have different uses, as well as advantages and disadvantages. The most commonly utilised modalities (by physiotherapists) are X-Ray, Ultrasound and MRI. So what is the difference? And what might you need?
X-Ray: Cheap and relatively easy, x-rays give us a clear picture of bones and joints.
Ultrasound: Gives us high quality images of soft tissue such as muscles, ligaments, tendons and bursa. Ultrasound is easy, quick and cost effective, however not as detailed or accurate as other forms of imaging.
MRI (Magnetic Resonance Imaging): Uses magnetic fields and radio waves to get a detailed 3D image of both bone and soft tissue structures. This is more expensive, but is the gold standard form of imaging in many cases.
When determining the appropriate imaging required, it is important to keep a few important points in mind:
- The correct form of imaging needs to be selected depending on the structures likely to be affected (e.g. there is no point ordering an x-ray if you don’t suspect a possible fracture).
- Imaging should only be used to complement a thorough clinical examination.
- There are many structural abnormalities that may be present in people, but not actually be relevant to their current condition or causing them pain (e.g. degenerative tendons, facet joint arthritis, disc bulges).
- The results of any imaging need to be interpreted within the context of the individual’s history and presentation. Whist imaging can provide us with high quality information, it does not always provide us with the perfect explanation!
Chris Bryceson
B. Health Sciences (Physio), APAM
CB Physiotherapy