Why are MRI Machines so Loud?

How Do MRI Machines Work?

If you’re scheduled for an MRI (magnetic resonance imaging) scan, you might wonder how these machines work. The very complex process can be simplified as follows.

The machine generates a strong magnetic field around you. That field causes particles in your body called protons to align in a particular direction. Radio waves (different from those used in X-ray imaging) sent to the scanned body area knock the protons out of alignment. When the radio waves are turned off, the protons realign and put out radio signals captured and analyzed by a computer to create detailed images.

It’s a painless outpatient imaging procedure, but you may have heard stories about the sound of an MRI machine. These devices make very loud noises as they work. Why are MRI scans so loud? The reason for the intense sounds is explained below.

Common Use Cases of an MRI

Doctors order MRIs for several reasons, including to:

• Capture images of organs
• Assess soft tissue injuries
• Look for problems in the brain or spinal cord
• Evaluate blood flow and blood vessel health

As explained above, MRI machines don’t use ionizing radiation (like X-rays), so this type of scan is a good choice for patients needing frequent imaging to monitor their condition. (Side note: People sometimes ask, “Are CT scans loud?” No, they use a different technology that isn’t noisy.)

Why MRI Machines Are Loud

The noise made by an MRI machine surprises many people. What does an MRI sound like? Many describe it as seemingly random clanking and thudding noises, making it seem like the device is malfunctioning. It isn’t, of course, but it can sound like it is.

How loud is an MRI? The sounds can reach around 100 decibels — equivalent to a power saw, a motorcycle revving its engine, or someone shouting directly into your ear. They’re created by gradient coils in the MRI machine. These coils have large amounts of electricity moving through them, alternating from positive to negative charge and back, which causes them to expand and contract rapidly (vibrate, essentially).

Ultimately, the mechanical stress on the coils produces noise. What do the different MRI sounds mean? The various types of energy pulses needed produce unique noises. And because you’re in a semi-enclosed space, the noise is amplified.

Keep in mind that the coils are designed and built to endure the mechanical stress on them with no problem.

Can MRIs Be Made Quieter?

Experts are working to lower MRI decibels and make the machines quieter. They’ve successfully reduced the volume, but that improvement has come at the expense of image quality. Research continues.

Reducing Noise in MRI Machines

What does an MRI sound like? Why are MRIs loud? Now that we’ve explained MRI noises in this article, you may wonder how to protect your ears during your procedure.

You can reduce the volume of MRI machine sounds reaching your ears and avoid the accompanying auditory discomfort by wearing earplugs or headphones. The same applies to anyone who stays with you in the MRI room during your procedure.

Listening to music or other content during your scan has the secondary benefit of taking your mind off what’s happening if being in a semi-enclosed space makes you uncomfortable. So, consider preparing a playlist if you like, and know that the MRI machine will be loud but produce detailed images that enable excellent care for your condition.

Next Steps and Helpful Resources

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