MRI Guide: Foot and Ankle

Each foot is comprised of 26 bones and 30 joints. Not to mention the additional muscles, tendons and ligaments. With so many structures and important junctures, if you are experiencing foot pain or ankle pain it can be difficult to pinpoint. Foot and ankle pain is typically described as a dull ache that increases in severity when weight-bearing.

The pain can sometimes feel insignificant, and we brush it off as a mild ankle roll or minor strain. The majority of foot pain is associated with sprains and strains–which require ice, elevation and keeping off the affected foot. If your pain has not improved with these remedies, it can be a sign of a more serious issue.

If you are experiencing this type of recurring or worsening foot or ankle pain, it is important to contact your doctor. They may order a foot and ankle MRI scan to help identify the root cause of your discomfort. Follow along as we will discuss the process of a foot MRI, how to read the resulting images of an MRI scan, and what to expect from the procedure.

What Do You See In a Foot MRI?

A magnetic resonance imaging (MRI) scan uses radio waves and a powerful magnetic field to generate images of a specified area of the body. During a foot and ankle MRI procedure, pictures–also referred to as slices–of the ankle and foot will be produced.

These images will show various structures of the area, including:

Bones
- Bottom of Tibia and Fibula
- Talus
- Calcaneus
- Tarsals
- Metatarsals
- Phalanges
- Sesamoids
Muscles
- Peroneals
- Gastrocnemius
- Soleus
- Tibialis Posterior
- Tibialis Anterior
- Tibialis Peroneal
- Extensors
- Flexors
Ligaments & Tendons
- Achilles tendon
- Lateral ligament complex
- Plantar fascia
- Plantar calcaneonavicular ligament
- Calcaneocuboid ligament
Additional Surrounding Soft Tissues

A radiologist will use the resulting images to identify any abnormalities. Such as tendon tears, inflammation, cartilage deterioration, or tumours.

How to Read An MRI of The Foot?

To understand how to read an MRI we must first discuss how MRI images are generated. An MRI takes slices across three planes:

Axial - Top Down
Coronal - Front to back
Sagittal - Side to side

Each image shows the structures of the ankle and foot as the MRI moves across each plane.

When a radiologist or radiographer interprets the results of an MRI, they are primarily looking for discolouration. The bones of the scan will appear to be dark grey. If there are patches of lighter or darker colours, it could indicate fluid collection, fracture, or abnormal growth.

Similar to the bones, the muscles and ligaments will also be different colours, usually light grey. The cartilage between the bones will appear very light, almost white. If there is discolouration in these structures it can indicate a tear, deterioration, or infection.

Radiologists are specially trained in identifying even the small nuances of MRI images.

Can An MRI Fix Foot & Ankle Pain?

MRI scans are powerful diagnostic tools. They cannot fix pain during the procedure. However, they do possess the ability to identify the potential cause of your foot or ankle pain.

By identifying the culprit of your discomfort, a treatment plan can be prescribed to begin your recovery and alleviate your pain.

What Can Be Diagnosed By a Foot & Ankle MRI?

With almost a quarter of the body’s bones located in the feet, there are numerous potential causes of injury. Although physical examinations are important, with so many structures in a confined area, an MRI scan can provide more detailed information. This allows doctors the opportunity to diagnose potentially serious issues.

These include:

Arthritis
Fracture
Tendon Tears
Gout
Lesions or Tumours
Inflammation
Infection

By increasing the accuracy of a diagnosis, an MRI can help find the correct treatment plan needed to alleviate your pain.

How Long Does A Foot & Ankle MRI Take?

The average foot and ankle MRI scan takes approximately 10–30 minutes. The scan requires you to remain extremely still. Small movements can cause distorted images and result in a longer scan.

How Is a Foot MRI Performed?

On the day of your MRI scan, you can expect:

Change Clothing
You will be brought to a room where you will change into a hospital gown. Some clinics allow you to wear your loose-fitting clothing, each will have its policies. All metal must be removed, including jewellery and piercings. Metal can interfere with the results of the scan, causing blurred or distorted images.
Brought to Exam Room
You will be instructed to lay down on the MRI table, feet first. Your head will not enter the machine. The radiographer may use foam pillows or another brace to keep your foot and ankle in the correct position for the scan.
Contrast IV
Some types of scans require an IV of contrast material. This is used to highlight certain structures more clearly in the scan. If needed you will have an IV administered, it will take a few minutes for the contrast material to make its way around your body. You may feel a temperature change, this is a common response and is to be expected.
Scan Begins
The table will slide into the MRI machine. The machine will make loud banging noises during the scan. This is perfectly normal and should not be cause for alarm. Focus on remaining as still as possible to ensure an accurate result. If you are uncomfortable at any point, simply inform the technician and they will work to make you as comfortable as possible. If you are claustrophobic you can ask for a mild sedative beforehand to help keep calm during the procedure.
Contrast IV Removal
Once the scan has completed, if an IV was administered, it will be removed. Take your time sitting up and standing, you may feel a little dizzy from contrast material and from laying down for a long period.
Change and Leave
You will be brought back to the original room where you can change back into your clothing and gather your belongings. If you have taken a sedative, you cannot operate a vehicle for several hours. Otherwise, you are free to continue your day.
Wait for Results
The radiologist will look over the images from your scan. Typically they will forward these to your doctor, along with their diagnosis. Your doctor will then contact you to discuss the results and prescribe a treatment plan–if needed.

The Bottom Line

It can be difficult to determine what threshold of pain is enough to have ankle or foot pain examined. If you have lasting or worsening foot pain, it is important to contact your doctor as soon as possible. What might seem like a small strain could be a more serious problem.

An MRI scan is a tool to help you get back to living without foot and ankle pain. At Scan.com we are committed to your health and wellness. If you are interested in avoiding the long wait times at the NHS, book an appointment with one of our centres in as little as 5 working days. Or if you would like additional information, contact us, our team is here to answer any questions you may have.

Foot and Ankle MRI