Foot and Ankle MRI: Info and Get a Scan

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. These usually settle with ice, elevation and keeping weight 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. This guide explains what the scan shows, which conditions it can diagnose, how the procedure works, what it costs, and what happens after your results come back.

What is a Foot and Ankle MRI?

Foot and ankle injuries are common in those who play sports or have a physically demanding job, and are also common after tripping or rolling over on the ankle. A foot and ankle MRI is a type of medical imaging scan that focuses on the foot and ankle area to assess for damage and to discover the cause of pain in the foot and ankle joint.

MRI is usually the preferred scan for this part of the body because most foot and ankle problems involve soft tissue: ligaments, tendons, cartilage and nerves. These structures barely show on a standard X-ray. An MRI captures bone and soft tissue together in a single examination, in enough detail to distinguish a partial tendon tear from a complete rupture, or a bone bruise from a true fracture. It does this without using any radiation.

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 chosen area of the body. During a foot and ankle MRI, pictures known as slices are produced of the ankle and foot.

These images show the structures of the area, including:

Bones: the lower ends of the tibia and fibula, talus, calcaneus, tarsals, metatarsals, phalanges and sesamoids.
Muscles: peroneals, gastrocnemius, soleus, tibialis posterior, tibialis anterior, and the extensors and flexors.
Ligaments and tendons: the Achilles tendon, the lateral ligament complex, the deltoid ligament on the inner ankle, the syndesmosis above the ankle, the plantar fascia, the plantar plate under the toe joints, and the plantar calcaneonavicular and calcaneocuboid ligaments.
Surrounding soft tissues: including the sinus tarsi, the small channel on the outer ankle that is a common source of pain after repeated sprains.

A radiologist uses the images to identify abnormalities such as tendon tears, inflammation, cartilage deterioration or tumours.

What Can a Foot and Ankle MRI Diagnose?

Pain, swelling and instability in the foot and ankle are the most common reasons for a foot and ankle MRI. This might follow an accident, a twisted ankle or a heavy object dropped onto the foot, or it might be pain and mobility problems with no obvious cause.

With almost a quarter of the body’s bones in the feet, there are many possible causes. A physical examination matters, but with so many structures in a confined area, an MRI provides more detail. It lets doctors diagnose problems that include:

• Ankle sprains, and repeated sprains that leave the joint chronically unstable.
• Broken bones and fractures, including hairline breaks that X-rays can miss.
• Stress fractures and repetitive microtrauma to bone or soft tissue.
• Bone abnormalities and swelling in the bone (bone marrow oedema).
• Plantar fasciitis, inflammation of the plantar aponeurosis, the thick band of tissue in the sole that supports the arch.
• A partial or full-thickness tear of a ligament or tendon, most often the peroneal tendons (peroneus brevis and peroneus longus) that stabilise the outer ankle.
• Tarsal tunnel syndrome, compression of the tibial nerve as it passes through the tarsal tunnel behind the inner ankle bone.
• Sinus tarsi syndrome, pain and instability on the outer ankle, often after repeated sprains.
• Cartilage injuries, including osteochondral lesions of the talus, where the cartilage and the bone beneath it are damaged, a common cause of deep ankle pain after a sprain.
• Lisfranc injuries, damage to the ligaments and joints in the middle of the foot that is easy to miss on X-ray and serious if left untreated.
• Flat foot deformity.
• Arthritis, including degenerative change in the many small joints of the foot.
• Gout.
• Lesions or tumours, including ganglion cysts and other soft-tissue masses.
• Inflammation and infection, including osteomyelitis (infection within the bone), which is hard to detect any other way.

By improving the accuracy of a diagnosis, an MRI helps identify the right treatment to relieve your pain.

Common Foot and Ankle Problems by Location

Where your pain sits is often the biggest clue to what is causing it, and it shapes what the radiologist looks for on your scan.

Heel and back of the ankle

Heel pain that is worst with your first steps in the morning points towards plantar fasciitis. Pain higher up, at the back of the ankle, suggests a problem with the Achilles tendon, from inflammation through to partial or complete rupture. An MRI shows thickening, degeneration and tears in both. If your symptoms are limited to this tendon, a dedicated Achilles MRI may be the more targeted option.

Outside of the ankle

The outer ankle takes the strain when you roll your foot inwards, which is by far the most common ankle injury. The scan assesses the lateral ligament complex for sprains and tears, and the peroneal tendons behind the outer ankle bone for splits and dislocation. Repeated sprains that never quite heal can leave the joint chronically unstable, and can cause sinus tarsi syndrome, a lingering pain on the outer ankle. A bad sprain can also chip the cartilage and bone of the talus, an osteochondral lesion, which shows on MRI but rarely on X-ray.

Inside of the ankle

Pain and swelling on the inner ankle can indicate a problem with the posterior tibial tendon, which holds up the arch of the foot. When it fails, the arch gradually collapses, a condition known as adult acquired flat foot. Burning, tingling or numbness spreading into the sole suggests tarsal tunnel syndrome, where the tibial nerve is compressed behind the inner ankle bone. An MRI can show both the tendon damage and anything pressing on the nerve.

Midfoot and top of the foot

Aching across the top or middle of the foot that builds with activity is a classic pattern for a stress fracture, particularly in the metatarsals and the navicular bone in runners. These hairline injuries often do not appear on X-rays for weeks, if at all, while an MRI picks up the bone swelling that comes before a visible fracture line. Midfoot pain after a fall or a trapped foot can also mean a Lisfranc injury, damage to the ligaments and joints in the middle of the foot, which is easy to miss and serious if left untreated.

Ball of the foot and toes

Sharp or burning pain in the ball of the foot, sometimes with the feeling of a pebble in your shoe, is typical of Morton’s neuroma, a thickened nerve between the toes. Pain under the big toe joint can come from the sesamoid bones, and pain in the joint itself from arthritis or bunions. An MRI helps separate these from each other and from a stress fracture, because the treatments differ significantly.

How a Foot and Ankle MRI Works

An MRI scanner uses radio waves and strong magnetic fields to create detailed images of the inside of the body. Each tissue in the foot and ankle, from the metatarsal bones (the long bones of the front of the foot) and the navicular bone (one of the small ankle bones) to the soft tissues including the deltoid ligament that supports the side of the foot, and the anterior talofibular ligament and posterior talofibular ligament that provide stability to the front and back of the ankle, contain hydrogen atoms.

During an MRI, the radio waves and magnets temporarily disrupt these hydrogen atoms, causing them to scatter and then realign. As they do, they create energy, each different tissue type creating different energy. Powerful computers detect these different energies, and turn them into distinct images. A radiologist can interpret these images and use them to detect differences between, for example, a normal Achilles tendon and a ruptured one, or a fine fracture line to one of the foot bones.

How to Read An MRI of The Foot?

To understand how to read an MRI, it helps to know how the images are made. An MRI takes slices across three planes:

Axial - looking from the top down.
Coronal - looking from front to back.
Sagittal - looking from side to side.

Each image shows the structures of the ankle and foot as the scan moves across a plane. When a radiologist interprets the results, they look first for discolouration. Bone appears dark grey. Patches of lighter or darker grey can mean fluid, a fracture or an abnormal growth.

Muscles and ligaments show as different shades, usually light grey. Cartilage between the bones appears very light, almost white. Discolouration in these structures can point to a tear, deterioration or infection. The same tissue also looks different depending on the scan setting used. Radiologists take several sets of images, known as sequences, such as T1-weighted, T2-weighted and STIR, because a problem that is invisible on one can stand out clearly on another. This is one reason interpretation is best left to specialists, who are trained to read even small differences in the images.

Can An MRI Fix Foot & Ankle Pain?

MRI scans are powerful diagnostic tools. They cannot fix pain during the procedure. However, they can 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. The section on what happens after your results below covers what those treatment plans typically involve.

How Long Does A Foot & Ankle MRI Take?

A foot and ankle MRI scan typically takes 20 to 30 minutes. If contrast dye is needed, allow extra time for it to be administered before the scan begins. 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 own 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 lie 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.

Benefits

MRI has clear advantages for the foot and ankle. It shows soft tissue, meaning the ligaments, tendons, cartilage and nerves, in far more detail than X-ray or CT, and it captures bone and soft tissue in a single examination. It uses no ionising radiation, unlike X-ray and CT, so there is no radiation dose to you. The scan is painless, and the magnetic field has no known lasting effect on the body. It is done as an outpatient, so once the scan is finished you can leave and, in most cases, drive yourself home.

Risks and Side Effects

Some foot and ankle MRI scans require the use of a contrast dye to highlight certain areas, such as blood flow to the soft tissues, including the medial ligaments that wrap around the inside of the ankle and provide stability. The dye used in MRI scans is gadolinium-based, unlike the iodine-based contrast used in X-ray and CT scans. Reactions are rare, but they can happen. Symptoms include feeling breathless, weak and sweaty. If you begin to feel unwell, let your radiographer know straight away.

Before your scan, you will complete a short safety questionnaire covering metal implants and devices. Pacemakers, implantable defibrillators, cochlear implants and some older surgical implants can be affected by the scanner’s strong magnetic field. Most modern orthopaedic implants are MRI safe, but always tell the booking team about any implant, device or metal fragment in your body before your appointment so they can confirm the scan is safe for you.

The closed nature of an MRI scanner can also make some people feel claustrophobic or panicked. Your medical team can provide a mild sedative if you think you may struggle, or you may prefer to book an open MRI scan, which uses a machine with more space around you.

How to Prepare for a Foot and Ankle MRI

An MRI of the foot and ankle requires little preparation. Unless otherwise advised, you can eat and drink as normal before your scan, and take any regular medications.

On the day, you will be asked to remove all metal, including jewellery, piercings, watches, hearing aids and glasses. Wearing loose clothing with no zips or metal fastenings may mean you can avoid changing into a gown, although each clinic has its own policy. If you have any implants or medical devices, mention them when you book rather than on the day, so the team can check they are MRI safe in advance.

Getting the Results

You will normally need to wait a few days for your results, once your radiologist has taken a look and discussed them with your referring doctor who can then refer you to a physical therapy specialist or recommend the right pain relief or surgery.

What Happens After Your Results?

What comes next depends entirely on what the scan finds, but most results lead down one of four paths.

Conservative treatment - Most soft tissue injuries, from ligament sprains to plantar fasciitis, are managed with rest, physiotherapy, orthotics or a walking boot. A clear diagnosis means the rehabilitation can target the actual injury rather than the symptoms.
Injections - Persistent inflammation, such as in Morton’s neuroma or some cases of arthritis, may be treated with a steroid injection, often guided by imaging to place it precisely.
Surgery - Complete tendon ruptures, unstable fractures and severe ligament injuries may need surgical repair. The MRI itself becomes part of the surgical planning, showing the surgeon exactly what needs fixing before they operate.
Reassurance - A normal scan is a genuinely useful result. It rules out the serious causes, which often changes how confidently you and your clinician can pursue rehabilitation.

If you want help understanding your report or deciding between options, a post-scan consultation lets you talk the findings through with a clinician.

Costs

In the UK, a private foot and ankle MRI scan costs between £200 and £500, depending on the clinic and your medical history.

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.

FAQs

Do you go all the way into the MRI machine for a foot and ankle scan?

No. You go in feet first and only your lower body enters the scanner. Your head stays outside the machine, which most people find makes the scan far more comfortable.

Can a foot and ankle MRI show nerve damage?

An MRI cannot image nerve function directly, but it can show swelling, compression or structural problems affecting the nerves in the foot and ankle, such as tarsal tunnel syndrome or Morton’s neuroma. This helps your doctor work out whether a nerve problem is behind your pain, numbness or tingling.

Do I need a GP referral for a private foot and ankle MRI?

You need a referral for any MRI scan, but you do not need to get one from your own GP. When you book through Scan.com, a clinician reviews your symptoms and provides the referral as part of the booking process.

Is an MRI better than an X-ray for foot and ankle pain?

It depends on what your doctor suspects. X-rays are quick and effective for showing most fractures and bone alignment. An MRI shows soft tissues such as ligaments, tendons and cartilage in far more detail, and can also pick up problems X-rays miss, including stress fractures and bone marrow swelling. For unexplained or persistent pain, an MRI usually gives the fuller picture.

Can I drive after a foot and ankle MRI?

Yes, unless you have taken a sedative for claustrophobia, in which case you should not drive for several hours and will need someone to take you home.

Foot and Ankle MRI

Is a Foot and Ankle MRI right for you?