What scan do I need for my painful foot: CT, MRI, Ultrasound or an X-Ray?

These are all imaging investigations we commonly use in our day to day practice. Other more specialised images are also used but not as frequently, such as SPECT-CT (nuclear imaging), DEXA scan. 

A common question amongst clinicians is which one is required when facing a specific condition that needs confirmation after seeing a patient in clinic. 

Here’s a brief guide:

  • X-ray – Easy access and very helpful to rule out fractures and assess arthritis of big joints. 
  • MRI scan – Very detailed caption of cartilage (OCL), stress fractures, tendons (tears or tendinopathy), and ligaments.
  • CT scan – A three-dimensional enhanced image ideal for bone conditions: very complex fractures, bone cysts or dislocations. A modern technique has been recently developed – the “standing CT” which is ideal for leg and foot deformities.
  • US scan – A dynamic modality that is useful for superficial soft structures such as tendons, ligaments or to help guide injections.

After an orthopaedic consultant has examined you, and the depending on the differential diagnoses suspected, they will advice on which is the best investigation modality.