Why Magnetic Resonance Imaging (MRI) is a Game Changer in Radiology Diagnosis

Whether you or someone you know has ever had an MRI scan done, there is no doubt that the technology is incredible. For over 50 years they have changed the world of radiology and medicine as we know it. This article is a deep dive into their function, the different types you get, how they compare to a CT scan, and where you can get an MRI done in South Africa.

What is an MRI?

Throughout history, inventions have often been attributed to individuals – but when it comes to MRIs, there are a number of researchers whose work contributed to the discovery of this technology. Built on the foundation of Nuclear Magnetic Resonance (NMR) and the underlying physics of MRIs, Paul C.

Lauterbur developed a way to encode spatial information into an NMR signal through the use of magnetic field gradients back in September 1971. His theory was published in 1973 which inevitably led to the first clinical MRI machines being installed in the early 1980s.

MRI machines are made up of two powerful magnets, which are considered to be the most important part of the equipment. If you recall back to the years of high-school physics, you may remember that the human body is mostly made up of water molecules, which are two parts hydrogen and one part oxygen atoms.

Within each atom is a proton which is sensitive to magnetic fields. MRI machines generate a magnetic field which affects the water molecules inside your body. This, in combination with the movement of hydrogen atoms creates data that radiologists can use to conduct detailed scans of your body and its organs.

In short, an MRI scanner is a piece of equipment that uses magnets, radio waves, and computer technology to generate detailed, cross-sectional images of your body, its internal organs, and structures.

The scanner is often compared to the shape of a donut and resembles a tube with a table down the middle that the patient slides in along. It does not make use of any radiation.

What are MRIs used for?

When it comes to examining soft tissue such as ligaments, muscles, and the brain, MRIs are the perfect tool. As previously mentioned, MRIs don’t make use of any ionizing radiation, instead, radio and magnetic waves vibrate the atoms in your body to generate an image. Since the soft tissue inside your body is high in water, MRIs are phenomenal at diagnosing conditions such as:

1. Brain & Spinal cord injuries including aneurysms, strokes, tumours, multiple sclerosis, epilepsy, and other neurological conditions. MRIs can distinguish between the many types of tissues found in your brain and spine, making it a powerful diagnostic tool for these areas.

2. Musculoskeletal injuries such as tears, sprains, and fractures in your tendons, bones, muscles, and ligaments.

3. Cancer in almost every part of your body. Thanks to the detail MRIs provide they can indicate the stage of cancer as well as how effective any current treatment is.

4. Heart and blood vessel related conditions such as aortic dissection, heart disease, and vascular malformations.

5. Abdominal and pelvic conditions found in organs such as the kidneys, liver, uterus, and ovaries. Some examples include kidney stones, liver disease, appendicitis, and inflammatory diseases.

This is not a comprehensive list and by no means should be used to determine whether you should go for an MRI scan. Always consult your local physician first.

Types of MRI Machines

Many people may not be aware, but there are actually two main types of MRI machines. The more common ‘donut-shaped’ machine is called a ‘closed-bore MRI machine.’ The other is an ‘open MRI machine.’ The closed machine takes higher quality images whereas an open MRI machine provides more comfort to the patient since it isn’t enclosed on every side.

If you feel nervous about your MRI scan, or experience claustrophobia, speak to your healthcare provider to discuss your options.

Different Types of MRIs

1. Functional MRI (fMRI)

A functional Magnetic Resonance Image is a type of MRI that focuses on measuring blood flow in the brain. It looks for metabolic changes as a result of cerebral blood flow and neuronal activation being coupled. Since these changes occur where the brain is active, these can be monitored and measured.

2. Magnetic Resonance Venography (MRV)

This type of MRI is specifically applied to the veins. It helps diagnose conditions such as blood clots, narrowing of the veins, and arteriovenous malformations.

3. Breast scans

A breast MRI often follows a patient’s biopsy where cancer may be present. It evaluates breast tissue and acts as a complement to mammography. Breast MRIs are particularly useful for patients who have dense breast tissue.

4. Cardiac MRI

As the name implies, cardiac MRIs give your physician incredibly detailed images of your heart and its structure. They also include information about your blood vessels, arteries, and circulatory system to find diseases such as congenital heart disease, artery disease, and damage due to heart attacks.

5. Magnetic Resonance Angiography (MRA)

Similar to MRVs, Magnetic Resonance Angiography focuses on your arteries. Contrast dye is often used to diagnose and evaluate conditions such as the narrowing of arteries, aneurysms, and deformed arteries.

What is the Difference Between an MRI & a CT Scan?

We go into more detail in our article around the difference between an MRI and CT scan here. They are often confused due to both of them being imaging techniques.

Despite their similarities, the main difference lies in the fact that MRIs make use of a magnetic field to generate images whereas CT scans use low-dosage ionising radiation. CT scans are quicker and are ideal for patients with metal implants whereas MRIs are excellent at examining soft tissue and may be preferred due to their lack of ionising radiation.

How Long Does an MRI Take?

There are a number of factors that influence how long an MRI can take. Typically, they range from 15-90 minutes, some variables include:

• Which part of your body is being scanned – Conducting an MRI of your leg is a lot less complicated than areas such as your brain or spine.

• Whether a contrast dye is used – This helps medical professionals by enhancing the visibility of certain tissues. If used, it may take longer for the dye to circulate.

• Number of required images – Depending on your condition, more or less images may be required which will directly affect the scan time.

• MRI technology – The MRI has come a long way since the 1970s, as technology progresses scan times may become faster as well.

Here is a general breakdown of how long an MRI might take:

• Shorter scans (5-10 minutes): When a specific area or larger image needs to be captured without much need for detail.

• General scans (30-60 minutes): Many MRI scans fall into this range, making it the most common.

• Longer scans (90 minutes): More advanced examinations such as ones involving multiple areas or where detailed images are required can take up to 90 minutes.

Keep in mind that this is only a general guideline, and a variety of factors can influence the length of your MRI scan. These numbers do not include consultation time, dressing, etc… It is always best to consult your doctor or radiologist with any questions you might have.

Benefits of an MRI

MRIs are the cornerstone of modern medicine and are excellent at generating detailed images of your body’s internal functions and structure. We’ve gone into more detail on the benefits in this article here. Below is a list of some of the benefits associated with MRIs:

Personalised Treatment Plans

MRIs allow medical professionals to more accurately diagnose conditions, monitor the effectiveness of their treatment, and choose an appropriate one thanks to the detailed images that they can produce. Treatment plans can be personalised as a result of:

• Accurate diagnostics
• Treatment monitoring
• Treatment identification

Improved Patient Care

Thanks to factors such personalised treatment and accurate diagnostics, medical professionals can conduct non-invasive treatments which improve their overall quality of life through:

• Personalised treatment
• Improved prognosis
• Non-invasive procedures

Early Disease Detection

Detecting diseases early can save lives and MRIs are ideal for identifying the kind of conditions that respond better to early treatment. For example, spotting a tumour before it develops means multiple treatment options can be considered as opposed to having to surgically remove it. This benefits patients through:

• Increased options
• Less aggressive treatment
• Better prevention

How you can prepare for an MRI

Although each situation will vary from patient to patient, here is a general guideline and some key things you can do to prepare for an MRI scan:

• Notify your doctor of any medical implants, conditions such as claustrophobia, or whether you may be pregnant.
• Speak to your doctor about any medication you are on.
• Avoid clothing that has metal such as zippers or underwire bras.
• Remove all jewellery including watches, earrings, and necklaces.
• In some cases, you may be required to fast up to a few hours before the scan.

Despite the fact that they look like something out of a science-fiction novel, MRI machines are very real and incredibly valuable to the medical world. Between their exceptional soft tissue visualisation, unmatched safety, and versatility across disciplines, Magnetic Resonance Imaging has changed the way we diagnose illnesses.

Motshudi Bergmann Ross Radiologists utilise state of the art equipment and provide services across a range of disciplines, including MRIs. You can visit our page and book an appointment here.