Thyroid Gland MRI

An MRI (magnetic resonance imaging) scan is a routine medical procedure doctors use to produce images of the inside of the body without having to perform painful, distressing invasive or surgical procedures. It’s a safe, quick, and painless tool for diagnosing or ruling out a range of medical conditions. 

An MRI scanning machine produces images that clearly show the difference between soft tissues such as organs, glands, muscles, ligaments and tendons, and dense bone tissue. MRI scans also highlight abnormalities and signs of disease and can be used to scan most parts of the body, including the thyroid gland. 

What is a Thyroid Gland MRI?

The thyroid gland sits at the base of the neck, in front of the trachea (known as the windpipe and connects the lungs to the air passages that pass through the nose and mouth). It’s a small, butterfly-shaped gland that forms part of the endocrine system that produces and regulates hormones. The thyroid hormones, thyroxine and triiodothyronine, are used by the body to regulate blood pressure and body temperature. However, their main role is to oversee metabolism, and therefore in turn, they also help to manage appetite and body weight. 

There are also four pea-sized organs situated around the thyroid gland, called the parathyroid glands, that are responsible for producing another hormone, called parathyroid hormone (PTH) that regulates calcium levels in the blood and bones. 

A thyroid gland MRI focuses on the neck and throat area and produces images of the thyroid gland and the surrounding tissues and structures. It gives details on the size, shape and overall health of the thyroid. A normal thyroid will look different from a diseased thyroid on an MRI. A diseased thyroid may appear larger, inflamed or irregularly shaped or may display small growths or cysts. 

What a Thyroid Gland MRI Can Diagnose

An MRI of the thyroid is a quick, pain-free and safe scan that assists doctors in diagnosing conditions that affect the health of the thyroid. These conditions include thyroid nodules and cysts, swellings and thyroid cancer, as well as conditions that may be affecting the trachea or the oesophagus (known as the gullet or food pipe and carries food from the mouth into the stomach). 

Thyroid Nodules

Thyroid nodules are small growths that appear on the thyroid, usually caused by an iodine deficiency. Usually non-cancerous, they need to be regularly monitored, as in some cases, they may turn cancerous over time. 

Goitre

A goitre causes swelling in the neck as the thyroid gland begins to expand in size. Usually caused by a deficiency in iodine, goitres are non-cancerous but can cause difficulties breathing, swallowing and speaking. 

Cysts or Fluid-Filled Masses

Thyroid cysts are small, fluid-filled sacs that can develop on the thyroid gland. They’re usually non-cancerous, but if left untreated, they can grow larger, causing problems with swallowing and speaking. 

Tracheal or Oesophageal Compression

If goitres, thyroid nodules or cysts are left untreated and they become large enough, they can begin to press on the trachea or oesophagus, making it very difficult to breathe, swallow, eat and speak. 

Thyroid Cancer

An MRI scan of the thyroid helps doctors diagnose thyroid cancer, usually alongside other tests such as an ultrasound and a fine needle aspiration (FNA) biopsy. An FNA biopsy involves doctors using a very fine, long needle to take a sample of cells from the thyroid gland. The cells are then tested in a laboratory to see if they’re benign (non-cancerous) or malignant (cancerous). 

Depth of Invasion (DOI)

Thyroid cancer can spread into the nearby trachea over time. A thyroid gland MRI can help doctors ascertain the Depth of Invasion, or DOI, which refers to how far a thyroid cancer may have spread into the tissues that surround the thyroid. 

Lymph Node Metastases

If a cancer spreads, it will cause secondary tumours called metastases. Thyroid cancer can spread to the nearby lymph nodes, and a thyroid gland MRI can pick up these lymph node metastases and any other further tumours in the area. 

Vascular Involvement

Vascular involvement, or vascular invasion, means that thyroid cancer has spread to the nearby blood vessels, and an MRI scan will be able to pick this up.

Soft Tissue Invasion

Thyroid cancer can also spread to the soft tissues, which can also be detected on a thyroid gland MRI scan. 

Recurrent Thyroid Cancer

If you’ve been diagnosed with thyroid cancer, you may have several thyroid gland MRI scans to track the progress of your condition during and after treatment and/or surgery. Recurrent thyroid cancer means being diagnosed with the condition more than once.

How a Thyroid Gland MRI Works

MRI scans are usually performed in the radiology department of a hospital or clinic. An MRI machine uses radio waves and a strong magnetic field to create images of the internal structures of the body. During an MRI, the radio waves and magnetic field temporarily disrupt the hydrogen atoms present in each cell. As a patient, you cannot feel this, but as the magnets are switched on and off, the hydrogen atoms align and then scatter, and as they do so, they create energy. The hydrogen atoms in bone cells create a different kind of energy than that created by soft tissues, such as those that make up the thyroid gland. 

These differences in energy are picked up by the MRI machine and are turned into images - the differences in energy clearly show the difference between tissues. Doctors then use these images to detect and diagnose abnormalities in the thyroid gland that are indicative of diseases such as thyroid cancer or conditions such as thyroid nodules. 

Benefits

MRI scans in general are considered to be the safest type of medical scan. Unlike CT scans and X-rays, MRI scans don’t utilize radiation, and therefore, there’s no risk of the dangers of radiation exposure. They highlight all of the structures inside the body and are particularly good at highlighting the soft tissues, making this kind of scan ideal for looking at the size and structure of the thyroid gland. A thyroid gland MRI can help doctors distinguish between different types of conditions that can affect the health of the thyroid. 

Risks & Side Effects

As MRI scans are considered so safe, they’re generally suitable for most people. However, for those who have claustrophobia or who struggle to remain still, it may prove difficult and distressing to have an MRI scan. 

MRI scans are unsuitable for patients who have certain types of medical implants that contain magnetic metal such as some pacemakers, cochlear implants, stents, valves, pumps and mesh implants. This is because magnetic metal will react with the strong magnets used in the MRI scanning machine which could prove to be dangerous if they move about inside the body. 

Some more modern, implanted medical devices don’t contain magnetic metal. It’s helpful if you’re able to bring the details of your implant to your appointment so that your medical team can check what kind of metal it might contain. 

If you have any concerns, raise them with your medical team before having your scan. They can supply a mild sedative to help you remain calm inside the MRI scanning machine and will advise you on the best course of action if you have metal implants that could be dangerous in an MRI scanner. You may be suitable for a thyroid gland ultrasound scan instead. 

How to Prepare for a Thyroid Gland MRI

Your medical team will give you full details on what you should and shouldn’t do before your thyroid gland MRI. On the whole, it will require very little preparation. You can normally eat and drink as normal beforehand and unless told otherwise, you can continue to take any medications as you would usually do. 

The Procedure Explained: What to Expect

A thyroid gland MRI normally takes around half an hour to complete and it will take place in the following stages. 

Screening for Metal or Implants

If you know that you have an implant that contains metal, speak to your medical team. It may be that the metal inside your implant isn’t metallic and is therefore safe. The same applies if you have a metal prosthesis or metalwork to repair broken bones, metallic shrapnel or bullets inside your body, or any tattoos that may contain metal. If you’re unsuitable for a thyroid gland MRI, you may be suitable for an ultrasound scan as an alternative. 

Changing Into a Gown (If Required)

In most cases, you will need to undress and change into a medical gown before your MRI scan. This makes it easier to remain comfortable in the scanning machine and removes the risk of accidentally getting into the MRI scanner wearing clothes that contain metal, such as belt buckles, bra hooks, buttons and zips. 

Lying on the MRI Table

An MRI scan involves lying flat on your back on a medical table, which then moves slowly into the tunnel-like MRI machine. When the magnets are switched on and off, you will hear a loud knocking sound that some people find daunting. Your radiographer will provide you with headphones to help muffle out the sound and you’ll be able to hear and talk to your radiographer through the headphones.

Use of a Neck Coil for Imaging

Some thyroid gland MRI scans are carried out while a dedicated neck coil is placed over the neck and throat. A neck coil is a small device that fits over the neck. It helps to enhance the images created by the MRI scanner, which makes it easier to diagnose some thyroid conditions. 

Contrast Injection (If Needed)

Depending on your symptoms, you may need a contrast dye, called gadolinium, injected into a vein before having a thyroid gland MRI (called a dynamic contrast-enhanced MRI, or DCE-MRI). This dye shows up on the MRI image results and helps doctors differentiate between cancerous and non-cancerous nodules and growths. 

Stay Still & Scan Completes

An MRI scan requires you to remain still throughout the process. Your radiographer may also ask you to hold your breath for a few seconds at certain times. This is to ensure the images created are as clear as possible. 

Once the scan is complete, the table will slowly move you out of the scanning machine, and you will be able to get up and get dressed. 

Getting the Results

Once the images have been collated, they will be sent to a specialist doctor called a radiologist, who is trained in reading MRI scans and diagnosing medical conditions using the MRI images. They will review the images and then discuss them with your referring doctor and potentially other specialist doctors, depending on the results. For example, if you need surgery for thyroid cancer, they will involve surgical and cancer specialists. If you require nutritional support, they may involve a dietician or nutritionist. 

Your medical team will then call you back to the hospital or clinic to discuss your results. It’s not usual for this to be the same day, it’s usually a few days or so later but this will depend on your particular hospital or clinic. 

Costs

In the UK, a private thyroid gland MRI scan will cost between £250 and £300. Any consultations or treatments will cost extra and will vary.

Get a Thyroid Gland MRI

Having symptoms of a thyroid problem, such as pain in the throat, difficulty breathing, swallowing or speaking, feeling a tightness or a lump in the throat or unexplained weight loss or weight gain can be worrying. The best way to put your mind at rest is to have a scan to find the cause of your symptoms. The sooner you get a diagnosis, the sooner you can begin treatment so that you can feel better and get on with living your life. 

Waiting for an NHS appointment may take several weeks or longer. Book a private thyroid gland MRI scan with us today, and start your journey to recovery. 

References

Tests for thyroid cancer. (n.d.). Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/thyroid-cancer/getting-diagnosed/tests-thyroid-cancer

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

What can a thyroid MRI help with? plus other thyroid evaluations. (2023, February 9). Ezra. https://ezra.com/blog/thyroid-mri

Thyroid nodules - Diagnosis & treatment - Mayo Clinic. (2022, February 11). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/thyroid-nodules/diagnosis-treatment/drc-20355266

Radiological Society of North America (RSNA) and  American College of Radiology (ACR). (n.d.-g). Thyroid scan and uptake. Radiologyinfo.org. https://www.radiologyinfo.org/en/info/thyroiduptake