Ankle MRI: Ligament Damage vs Occult Fractures

MRI 02 October, 2026

Understanding ankle MRI

Magnetic resonance imaging (MRI) is an advanced medical imaging technique that produces highly detailed images of the inside of the body, particularly soft tissues, organs and bones. Unlike X-rays or CT scans, MRI does not use ionising radiation. Instead, it uses powerful magnets and radio waves to create images.

During an MRI scan, a magnetic field temporarily affects tiny particles called protons within the body’s tissues. Radio wave pulses then alter their position, and as they return to normal, they release energy. This energy is detected by the scanner and converted into detailed cross-sectional images, sometimes in 3D.

An ankle MRI scan can show damage to bones, ligaments, tendons (eg peroneal tendons) and muscles in the ankle joint. Due to the higher quality images produced, ankle MRI can detect subtle changes that may not show on an X ray or ultrasound scan.

Recognising common ankle conditions

Ankle sprains and strains are a very common injury. They often damage a muscle or ligament, but can also cause tendon damage. Most get better within 2 weeks with rest and pain relief medication.

However, more severe ankle injuries can take longer and may need investigation with an ankle MRI scan. This includes certain ligament injuries and subtle fractures. Early detection can help speed recovery with effective treatment.

Ligament damage: ATFL injury and high ankle sprains

There are 3 main ligaments on the outer side of your ankle: the calcaneofibular ligament (CFL), posterior talofibular ligament (PTFL) and anterior talofibular ligament (ATFL).

An ATFL injury occurs when your foot and ankle forcefully roll inward, overstretching the anterior talofibular ligament. This causes ligament tears, or in severe cases, rupture.

A high ankle sprain refers to damage to any of the ligaments in the upper part of your ankle that connect your 2 lower leg bones (tibia and fibula). It usually occurs when the ankle forcefully rolls inward or outward while the foot is flexed. This causes the ligaments to overstretch and then tear or rupture.

High ankle sprains are often sports injuries as they usually happen due to a collision when running or jumping. They take longer than low ankle sprains to heal, so you need to rest them for longer before you can return to your everyday activities.

Less commonly, other ligaments can be damaged eg the deltoid ligament that stabilises the inner ankle.

Occult fractures and stress fractures

Stress fractures are tiny fractures (breaks) in the bone. They’re caused by overuse and repetitive strain, rather than a sudden injury. As stress fractures can be very small, they can be missed on an X ray.

Small fractures that are missed on X ray imaging are called hidden or occult fractures.

Avascular necrosis of the ankle

Previous broken bones or severe ankle sprains can affect blood vessels in your foot and ankle. This can cause blood flow to the bones to be reduced or cut off. In the foot, the metatarsal bones are usually affected. In the ankle, it’s usually the talus bone in the centre of the ankle. This result can lead to avascular necrosis, where the bone cells start to die.

Although rare, it’s a serious condition that can lead to the bone collapsing. Symptoms include deep ankle pain that gradually increases and is worse when you’re on your feet for long periods of time.

Of all the ankle scans available, an ankle MRI is the most sensitive for detecting this condition.

Symptoms that lead to ankle MRI referral

Your healthcare provider may recommend an ankle MRI scan if you have ankle instability, pain and/or swelling that has not improved after 2 weeks of rest. You may also have an acute injury with ankle pain but a clear X ray.

What to expect during an ankle MRI

When you arrive for your ankle MRI, you’ll be asked to remove all metal items from your body. This is because metal may be attracted to the magnet, heat up or interferes with the clarity of the scan images. If you have metal implants that aren’t compatible with MRI, you may need to have a different type of scan. Our Radiographers will ask you some questions to establish if it is safe for you to have an MRI. You may be asked to change into a hospital gown, so wear loose clothing that’s easy to change out of.

As you’ll be having your ankle area imaged, you’ll be positioned inside the MRI machine feet-first while lying down on a patient table. Your upper body is outside of the machine.

When your scan begins, you’ll need to lie still to ensure clear images are created. You’ll hear loud banding, clicking and knocking noises – these are the normal sounds of the MRI machine working. You will be given special earplugs and headphones to protect your hearing and reduce the noise. If the noises bother you, your care team can provide you with music to listen to.

At Vista Health, when your scan is complete, we aim to send you a report with your MRI results within 3 working days. Your report will be overseen by an experienced consultant radiologist.

Get rapid access to an ankle MRI scan

If you have persistent pain or swelling of your ankle, a private MRI scan with expert insights can help you reach an accurate diagnosis. At Vista Health, you don’t need a GP referral letter. Simply self-refer and book online at any of our nationwide clinics.