Plantar Fasciitis MRI Scan: When You Need It and How It Works

What is a plantar fasciitis MRI?

A plantar fasciitis MRI is a non-invasive imaging test that gives your doctor a detailed view of your foot and, in particular, your plantar fascia.

The plantar fascia is a thick fibrous band of tissue that stretches across the arch of your foot. If you have recurring heel pain, your doctor may suggest an MRI to look for inflammation, minor tears or other damage that could be related to plantar fasciitis.

Unlike X-rays, which mainly show bones, MRI scans provide clear images of soft tissues, making it easier to identify the specific cause of your pain. This test also helps to rule out other conditions that could be causing similar heel or foot pains.

How do I know if I have plantar fasciitis?

The symptoms of plantar fasciitis most commonly include:

• Pain in your heel

• Pain along the arch of your foot

• Stiffness in your foot

• Swelling near your heel

• Tightness in your Achilles tendon (the thick tendon at the back of your ankle)

What does plantar fasciitis feel like?

Plantar fasciitis typically causes an aching pain in your heel or across the bottom of your foot. The pain changes based on your activities and time of day:

• Many people feel the worst pain when taking their first steps after waking up or after sitting for a long time. This pain often gets better after walking around for a few minutes.

• You might feel a constant dull ache throughout the day.

• You could experience sharp, stabbing pains when you put weight on your foot or press on your heel.

• Moving around or exercising might make your foot feel temporarily better, but the pain often returns or gets worse once you stop.

• Morning pain is especially common; this is a classic sign that doctors look for when diagnosing plantar fasciitis.

If you're experiencing persistent heel pain, stiffness, or swelling that isn't improving with rest or home remedies, it’s recommended to consult a healthcare provider. Request an appointment with Thomson Medical for a comprehensive evaluation. 

Our specialists will assess your symptoms and may recommend a plantar fasciitis MRI to accurately diagnose your condition and develop a personalised treatment plan tailored to your needs.

What are the risk factors of plantar fasciitis?

Plantar fasciitis can affect anyone, but certain factors increase your risk of developing this condition. Here are some key risk factors to consider:

• Age

  • You are more likely to experience plantar fasciitis if you are between 40 and 60 years old.

• Types of exercise

  • There are specific workouts and exercises that can place your heel under a significant amount of stress, such as long-distance running or high-impact workouts that put strain on your feet.

• Foot mechanics

  • Even abnormal walking patterns can strain your foot if your weight isn’t evenly distributed.

• Your job

  • If you have a job that involves more walking or standing, you are at a greater risk of plantar fasciitis.

Some people ignore plantar fasciitis and its pain, hoping it will go away. If you don't treat it, it could disrupt your daily activities and develop into a chronic condition that leads to additional complications.

When is a plantar fasciitis MRI needed?

In the following situations, your doctor may recommend an MRI scan for plantar fasciitis:

• Persistent symptoms

  • If your heel pain persists despite treatments like rest, stretching, or anti-inflammatory medications

• Uncertainty in diagnosis

  • When your doctor suspects another condition may be causing your symptoms or wants to rule out injuries that mimic plantar fasciitis

• Severe pain or swelling

  • If you have intense, localised heel pain or swelling that doesn’t improve over time

• Assessment of other foot conditions

  • An MRI can also help identify or rule out other medical conditions, such as heel spurs, tendinitis, or nerve damage.

How do I prepare for a plantar fasciitis MRI scan?

Preparing for a plantar fasciitis MRI is relatively simple:

• Clothing

  • Wear loose, comfortable clothes without any metal parts, such as zippers or belts, as metal can interfere with the MRI.

• Remove metal objects

  • Before the scan, remove all metal items, including jewellery, watches, and piercings.

• Medical history

  • Inform the technician if you have metal implants, pacemakers, or other medical devices, as the MRI's strong magnetic field can affect them.

• Contrast dye

  • If your doctor plans to use a contrast dye (a special liquid that helps highlight certain areas), you might be asked to fast for a few hours beforehand, though it is not always required.

How does the test work?

An MRI for plantar fasciitis uses powerful magnetic fields and radio waves to create detailed images of the soft tissues in your foot. The entire process usually takes 20 to 40 minutes. Here’s what you can expect during the procedure:

• Positioning

  • You will lie down on a table that slides into the MRI machine, a large, tube-like device.

• Imaging process

  • The machine captures images of your foot while you remain still. This procedure ensures that the images are clear and accurate.

• Contrast dye (if used)

  • If your doctor decides to use a contrast dye, they will inject it into a vein in your arm. This dye helps highlight areas of inflammation or abnormal tissue, providing clearer images.

• Breathing instructions

  • You might be asked to hold your breath for a few seconds during the scan to prevent motion blur and ensure the best possible images.

What are the potential risks and side effects of this test?

While MRI scans are generally safe, there are a few potential risks and side effects to be aware of:

1. Magnetic field risks

   • The strong magnetic field used in MRI scans can pose risks for individuals with certain metal implants, pacemakers, or metallic devices.

   • It is important to inform your healthcare provider about any such implants before undergoing an MRI.

2. Contrast dye risks

   • If a contrast dye is used, there is a slight risk of an allergic reaction or kidney problems, particularly for those with pre-existing kidney conditions.

   • Your healthcare provider will assess these risks and discuss them with you beforehand.

3. Claustrophobia

   • The enclosed space of the MRI machine can cause anxiety or claustrophobia in some individuals. If you have concerns about this, discuss options like sedation or using an open MRI machine with your doctor.

Rest assured, your healthcare team will take every precaution to keep you safe and comfortable during the procedure.

FAQ

Does plantar fasciitis show up on MRI?

Yes, MRI can detect plantar fasciitis, especially when there is significant inflammation, swelling, or tearing in the plantar fascia. It can also help identify other conditions like bone spurs or calcaneal spurs (small pointed growths on the heel bone) or soft tissue damage that might be contributing to the plantar heel pain.

What is the best imaging for plantar fasciitis?

While MRI is one of the best imaging methods for diagnosing plantar fasciitis and assessing its severity, ultrasound is often used in clinical settings due to its accessibility, speed, and ability to show real-time movement of the tissues. However, MRI provides more detailed images, especially when other conditions need to be ruled out.

What is the normal thickness of plantar fascia on MRI?

For most patients, the normal plantar fascia thickness on MRI is less than 4 millimetres. If the fascia measures more than this, it could suggest plantar fasciitis, especially when other signs like swelling or inflammation are present.

Can an MRI show nerve damage in a foot?

Yes, MRI can show nerve damage or compression in the foot, particularly if there is associated inflammation, swelling, or abnormalities in the tissues surrounding the nerves. 

What is the gold standard imaging for plantar fasciitis?

MRI is generally considered the gold standard for imaging in diagnosing plantar fasciitis because it provides the most detailed pictures of soft tissues, allowing doctors to assess inflammation, thickening, or tears in the plantar fascia.

What tests confirm plantar fasciitis?

The clinical diagnosis in patients with plantar fasciitis pain usually starts with a physical exam and review of symptoms. However, your doctor can use imaging tests like ultrasound and MRI for the diagnosis if symptoms persist despite conservative treatment for plantar fasciitis pain.

These tests help confirm the findings of plantar fasciitis and rule out other conditions like stress fractures or heel spurs.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations based on your medical conditions, request an appointment with Thomson Medical.