If you ask a friend what MRI stands for or to explain how it works, you’ll likely be met with an empty stare. Few people understand how these incredible machines create such detailed images.

Let’s take a quick look at the process of an MRI and some of the advantages that it has over other medical tests.

What is an MRI?

“MRI” stands for magnetic resonance imaging. This imaging technique uses extremely strong magnets to produce detailed 3D images of a patient.

In layman’s terms, this complex process works by stimulating the protons in our body through magnetic fields and radio frequencies. Sensors in the MRI then detect the energy that is released by those protons. This method allows doctors to reveal microscopic details that are unavailable through other tests.

How does getting an MRI work?

An MRI machine is shaped like a large tube with openings at both ends. The patient is placed on a table that slides in and out of the machine. The instructions are usually very straightforward – “Hold still.” If someone moves too much during a scan, it can make the images blurry and difficult to see.

During a scan, an MRI machine creates a loud tapping or knocking noise. It’s not uncommon for someone to be given a pair of headphones to wear during a scan. Most machines also feature an intercom system so that a patient can communicate with doctors during the scan.

A typical scan lasts anywhere from 15 to 90 minutes. Once the images are completed, they’re sent to a radiologist to review and interpret. Depending on the situation, MRI results can be available within just a few hours.

What is the advantage of an MRI?

An MRI can reveal injuries that cannot be seen with other imaging tools like an X-ray or CT scan. This makes them incredibly useful when evaluating injuries to a patient’s spine, muscles, and ligaments.

MRIs can even create detailed images of the brain and other organs, allowing doctors to look for bleeding, tumors, or other injuries.

It’s not uncommon for a patient’s X-ray to look completely normal while an MRI of the same area reveals a serious injury or illness.

Is an MRI dangerous?

Although an MRI doesn’t emit radiation like an X-ray or CT scan, the use of strong magnets does make it dangerous for anyone with metal in their body. The magnetic force created by an MRI machine is strong enough to launch a wheelchair across a room. For this reason, an MRI may not be available to people with metal implants.

Other groups of people that may avoid MRIs are those who suffer from claustrophobia, are sensitive to noise, and are pregnant. If you’re nervous about an MRI scan for any reason, always share those concerns with your doctor.

Why doesn’t everyone get an MRI?

Not only are MRIs effective, they’re also expensive. A single machine can cost anywhere from $1-3 million. It’s not uncommon for a quick scan to cost thousands of dollars.

Depending on the seriousness of an injury, a doctor may perform more cost-effective tests before turning to an MRI.

Although costly, MRIs are one of the greatest tools that doctors have at their disposal when it comes to diagnosing injuries.

Source: National Institute of Biomedical Imaging and Bioengineering. Always consult with your doctor(s) before before making any medical decisions.