MRI Scanner – What Makes That Banging Noise?

For those of us who are advancing in years, it would be unusual to hear of of anyone with health issues who has not at least heard of the claustrophobic MRI (Magnetic Resonance Imaging) machine. My first experience was back in the 1980s when I needed a scan of my lower back as a prerequisite to surgery.

One must understand that, at the time, this was the newest and greatest machine available to pinpoint why I was suffering from such disabling back pain that I was unable to perform everyday tasks — such as tying my own shoes. Because of the pain, I had sought out a neurologist who had already tried to treat the symptoms with an array of known medications and through physical therapy. However, nothing had brought the desired results or relieved the horrible pain in my aching back.

Knowing that options were becoming limited, he then told me about a machine called an MRI. This machine was different than the standard x-ray machine in that it worked through the use of magnets and had been proven to see what was going on inside of the skeletal frame. Not understanding what this test would entail, I can still recall how on that day I arrived with a sense of trepidation. The first thing that the clinician instructed me to do was to remove all of my clothing and jewelry (including my wedding ring). They then gave me one of those open-in-the-back hospital gowns that we all detest. For those of you who have experienced the joy of exposing your posterior to the world, you know exactly what I am talking about.

Once I had complied, they then directed me to a machine that reminded me of a tight chamber that you might find when climbing through passageways of a cave. That in itself was not reassuring, but I did as asked. Once settled in this airless tunnel, I was then given several instructions that needed to be followed in order for the scan to function properly. These instructions included the following:

  • No movement was allowed. This could distort the image.
  • If I needed help, there was a built-in microphone and speaker to request assistance.
  • There would be a loud noise during the entire test and I shouldn’t let it bother me.

Before this experience, I had never considered myself claustrophobic, but being in this machine changed the way that I would forever feel about small, cramped spaces. This feeling was complicated by the lack of ventilation, which made it seem as if I was breathing in my own carbon dioxide instead of fresh air. Additionally, the loud noise that they had warned me about could have been compared to the sound of a jackhammer beating inside of a drum, and it resulted in a horrendous headache. Like all unpleasant experiences, it finally ended, but it left me feeling weak and totally drained of strength. Needless to say, it was definitely an unpleasant experience.

With this experience in mind, I wasn’t excited when, last Monday, my doctor said that I needed an MRI scan to confirm that I had torn my rotator cuff. However, being the adult that I am, I arrived for the test on time. When I was called back, the prep went the same with the removal of all metal etc., but during this test, things were different. These are a few differences I noted:

  • I was given ear plugs to muffle the banging sound.
  • The tube I slid into seemed to be more accommodating in size.
  • The technicians gave me a set of earphones that channeled music into the machine.
  • The machine now blew fresh air over my body, making it easier to breathe.

With these changes, the test was much more tolerable and basically uneventful. Of course, it helped that I had already prepared myself for the experience. I chose to keep my brain occupied during the test by concentrating on one specific topic. My wife had also suggested that I try to take a nap — something that works for her.

At the end of the test, I asked one of the technicians, “What is that banging sound’ when the MRI scan is run?” He kindly gave me a quick rundown of what happens during the testing procedure.

There are apparently large metal coils inside of the MRI scanner called gradient coils that electricity passes through. This electricity passing through the metal coils creates a magnetic field that sends out magnetic waves. These waves then measure the tissue in our bodies and produce an image. The banging noise occurs when this large amount of electricity hits the coils which, in turn, causes them to vibrate. The technician also explained that an MRI scan is the best technique to find brain tumors and to determine if a tumor has spread to other areas of the brain.

MRI scans are a valuable tool to doctors in many fields as they can provide an image of the following body areas:

  • Brain and spinal cord
  • Joints and bones
  • Heart and blood vessels
  • Any internal organ — including the heart or lungs

Be assured that if your doctor recommends that you get an MRI scan, it is necessary since it is one of the only ways for them to get a clear image and make an accurate diagnosis. I promise you that you will survive and, even if it appears frightening, you just need to close your eyes and think about something else.

Comments welcome.

CC licensed Flickr photo above shared by stumayhew

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I have been writing for Lockergnome for eight years.