An MRI, or magnetic resonance imaging, scan is a medical scan that uses radio waves and a strong magnetic field to create images of the inside of the body. MRI scans are routinely used by medical professionals as a painless and quick way of diagnosing a wide range of medical conditions affecting numerous parts of the body, without using invasive or surgical techniques. MRI scans can be used to scan most areas of the body, including the lower leg, heel and foot.

What is an Achilles Tendon MRI?

An Achilles tendon MRI is an MRI scan that looks specifically at the heel and calf, as well as the foot and ankle, to give medical experts an idea of what might be causing pain or immobility in the region and to diagnose disorders of the Achilles tendon.

Reasons for an Achilles Tendon MRI

A tendon is a strong band of fibrous tissue that attaches muscles to bones. The Achilles tendon (sometimes referred to as the Achilles heel) is a thick, strong tendon that attaches the calf muscle to the heel bone. It can withstand a lot of pressure from walking, running, bending, twisting, pivoting and lifting movements and is the tendon that allows us to stand on our tip toes and flex our feet.

However, sometimes, when under extreme stress, such as through exercise or due to an accident, the Achilles tendon can tear or rupture. The most common sign of an Achilles tendon rupture is feeling a sudden snap at the rear of your ankle, and you may also hear a popping sound. Some patients describe it as feeling as if something has hit the back of their ankle, but this is actually the tendon snapping. This causes a sudden, sharp, intense pain in the area.

The Achilles tendon can also be prone to other conditions, such as inflammation and fluid accumulation, leading to other signs that you may have damaged your Achilles tendon, including:

Tenderness in the affected area
Bruising and swelling
Redness and heat
Stiffness
A thickening of the tissues in the area
Limited range of motion
Difficulty walking and flexing the foot, especially to walk upstairs or up a hill or an incline

If you have any of the symptoms above, an Achilles tendon MRI will be helpful in getting a diagnosis and treatment. Your medical team may also organise an ultrasound scan of the area, depending on your symptoms.

What an Achilles Tendon MRI Can Diagnose

An Achilles tendon MRI can help doctors discover the reason for your pain and diagnose an Achilles tendon rupture or other foot, heel and ankle disorders, including:

Achilles Tendon Tear

An Achilles tendon tear or rupture is a painful and sudden injury, causing intense pain at the back of the ankle. It can be caused by a sports injury or slips, trips and falls that force the foot into a sudden upward position.

Tendonitis (Inflammation)

Tendonitis, or inflammation of the Achilles tendon, causes pain and swelling in the back of the ankle. The tendon is still intact, but it’s become inflamed, usually due to overuse through sports, exercising without warming up or wearing high-heeled shoes for long periods of time.

Tendon Degeneration (Achilles Tendinopathy)

Tendon degeneration, also called Achilles tendinopathy, is caused by tiny tears and repetitive stress to the tendon, leading to a gradual onset of pain in the Achilles. The early stages can be described as acute Achilles tendon degeneration, or tendonitis, and if it progresses, it may be described as chronic Achilles tendinopathy, or tendinosis.

Fluid Accumulation (Effusion)

Swelling in the Achilles is caused by a buildup of fluid in the area that can itself be caused by other conditions affecting the Achilles, such as tendinopathy (see above). It may also be caused by a small sac of fluid called a bursa that cushions the area, bursting through injury.

Partial Tears or Strains

The Achilles tendon can become partially torn or ruptured, otherwise known as a strain, again due to accident, injury or overuse.

Calcifications or Deposits

If the fibres of the Achilles tendon develop small tears from repetitive stress, they can become hardened as a result of calcification, or a buildup of calcium deposits, causing pain and thickening of the tendon.

Tendon Thickening

Achilles tendinopathy and calcification (see above) can lead to a thickening of the tendon, causing pain, swelling and stiffness.

Scar Tissue or Fibrosis

Previous injury or surgery to the Achilles tendon can also cause a buildup of scar tissue and a thickening of the tissues in the area, causing pain and stiffness.

Infection or Abscesses

Ankle and foot wounds, caused either through accidents or surgery, can sometimes become infected, leading to a pus-filled abscess in the tendon. The ankle will become hot and red, tender to the touch and potentially very painful.

How an Achilles Tendon MRI Works

An MRI scanning machine uses radio waves and strong magnetic fields to temporarily disrupt the hydrogen atoms in the body. During an MRI, the strong magnets are switched on and off, and as they are, the hydrogen atoms from different tissues give off different types of energy. Soft tissues, such as tendons, give off a different kind of energy to denser tissues such as bone.

The differences in energy are picked up by the MRI machine, and computer programming turns them into images. A trained medical professional called a radiologist can detect the difference between different types of tissue. Damage to the soft tissues of the Achilles tendon, such as ruptures, and other abnormalities, such as calcium deposits, inflammation, fluid buildup, pus, and other signs of infection, can also be detected by a trained eye.

Benefits

An MRI scan is very effective at picking up abnormalities in the bones and soft tissues of the body, and can clearly highlight ruptures, inflammation, degeneration, fluid accumulation, calcifications and signs of infection in the foot and ankle. It’s a quick, pain-free scan and the results are relatively quick. An Achilles tendon MRI is also very good at distinguishing between different disorders of the Achilles.

Risks & Side Effects

MRI scans are suitable for most people, and there’s no evidence to suggest that the radio waves and magnetic fields pose any risk to the human body.

However, they’re not suitable for patients with certain metals inside their body that cannot be removed, such as those found in some pacemakers, cochlear implants, stents, valves, pumps and prosthetics.

If you’re concerned about anything, speak to your medical team beforehand. Your doctor will discuss the risks and benefits with you if you’re pregnant. Patients with claustrophobia or who struggle to remain still may also find having an MRI scan difficult. If you decide that an MRI scan isn’t for you and you have pain in your Achilles tendon, you may be suitable for an ultrasound scan instead.

How to Prepare for an Achilles Tendon MRI

Your medical team will give you all the information you need prior to your scan. It can be helpful to arrive at your appointment wearing loose-fitting clothing that’s easy to remove, and carrying as few metal objects as possible (see below).

Unless otherwise advised, you can continue to eat and drink as normal beforehand, and carry on taking any regular medication.

The Procedure Explained: What to Expect

An Achilles tendon MRI is a routine and straightforward medical scan that usually takes no longer than half an hour.

Remove Metal Objects

When you arrive for your appointment, you will be asked to leave all metal objects, including jewellery, watches, belts, coins, mobile phones and bank cards in a safe place outside of the room. This is because magnetic metals can react with the strong magnets in the MRI machine and potentially cause harm. Your medical team would’ve discussed any potential metal that cannot be removed from your body beforehand.

Change Into a Gown

For most MRI scans, you will need to undress and change into a hospital gown, regardless of the area being scanned. You will be given a safe area to leave your clothes and belongings.

Positioning on the MRI Table

Your radiographer will help you into the correct position on the MRI table to ensure that your scan is taken correctly. You will be lying on your back on a hospital table or bed that slowly moves into the MRI scanning machine.

MRI Scanning Process

Once the table or bed has moved into the machine, it’s important that you remain very still. You will hear a loud knocking sound as the magnets are turned on and off, and you will be given headphones to wear to help muffle the sound.

Your radiographer will be able to speak to you through your headphones, and they may ask you to hold your breath at certain points. If you struggle with claustrophobia, you may be given a mild sedative beforehand to help keep you calm and still. The whole process should take no longer than 20 to 30 minutes.

Radiologist Review and Report

Once your radiographer is happy with the images they’ve taken, they will collate them and send them to a specialist doctor called a radiologist for review. A radiologist is trained to detect abnormalities such as a rupture, disease or inflammation in the Achilles tendon.

Getting the Results

It’s not common to receive your Achilles tendon MRI results straight away, as they need to be assessed and discussed by your radiologist and referring doctor, and if necessary, a surgeon who specialises in tendon repair. Therefore, it may take a few days before your referring doctor arranges to discuss your results with you.

You may also need to be referred to a physiotherapist who can help with your rehabilitation, either with or without surgery.

Costs

In the UK, a private Achilles tendon MRI scan costs between £200 and £300. Consultations and treatments, including physiotherapy and surgery, will cost extra.

Get an Achilles Tendon MRI

If you have pain, discomfort or stiffness in your Achilles tendon area, or you think you’ve injured it, getting an MRI scan will help you get a diagnosis, allowing you to start treatment. You may have to wait several weeks or months before getting a scan with the NHS, so if you’re looking to book a private Achilles tendon MRI scan, book via our simple booking system today and start your journey to recovery.

FAQs

What Type of MRI for Achilles Tendon?

An Achilles tendon MRI should include both T1 and T2 imaging - your medical team will know exactly what protocol to use, depending on your symptoms, and will explain everything you need to know.

How Long Does an Achilles Tendon MRI Take?

An Achilles tendon MRI usually takes around 20 to 30 minutes.

References

Achilles tendon rupture. (2025, March 19). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/21703-achilles-tendon-rupture

NHS inform. (2025, February 7). Achilles tendinopathy | NHS inform. NHS Inform. https://www.nhsinform.scot/illnesses-and-conditions/muscle-bone-and-joints/leg-and-foot-problems-and-conditions/achilles-tendinopathy/

Badii, C. (2023, July 3). Achilles Tendinitis. Healthline. https://www.healthline.com/health/achilles-tendinitis

Website, N. (2022f, August 5). MRI scan. nhs.uk. https://www.nhs.uk/conditions/mri-scan/

Achilles MRI