Thursday, September 27, 2012

How MRI Works

By Hailey Gothard
Medica Stand Up Imaging

MRI, or Magnetic Resonance Imaging, is based on physics. MRI uses the magnetic field, your protons and neutrons, along with radio frequencies to create images of your body. More specific to protons and neutrons, MRI uses the hydrogen atoms in the body to create images. The human body consists of 60 percent water, which makes it easy to image the human body. When the body is put into the magnetic field, your hydrogen atoms either line up with the direction of the magnetic field or against it, which cancels them out completely, but there is always ONE hydrogen atom left. This is where the radio frequencies come in – MRI is able to run different sequences to look at your tissues (Fat vs. Fluid) by using different radio frequencies. By using radio frequencies to create images, no radiation is used in MRI.

Many MRI patients ask: what is that knocking noise? It is the gradients and radio frequency coils switching to make your images. MRI takes pictures of the patient's body in three planes: axial, sagital, and coronal. Imagine three slices of bread. This is why the patient never has to move. Compare to X-ray pt moves for every x-ray. Another important fact to know is you must hold still during your MRI to get the best image possible. Exams last between 30 minutes to an hour.

Why would my doctor choose an MRI?

  • Looks at tissue and NOT bone like X-ray and CT (Structural: is anything out of place)
  • Exams:
  • Multiple Sclerosis
  • Tumors of brain
  • Torn ligaments (ankle, knee wrist)
  • Shoulder injuries
  • Soft tissue masses
  • Herniated discs in spine
  • Early Stage Strokes

MRI Safety: Show screening form

  • No pacemakers, aneurysm clips
  • Remove hearing aids, dentures
  • Remove all metal (blue jeans if having lower back hips done) (bras)
  • Heart stints: Good after 6 weeks
  • Surgical metal ok (I.e. knee, hip replacement) but if scanning that area could cause an artifact
  • No cell phones, watches, wallets (magnetic field erases credit cards)

Stand-up MRI

  • History: Dr. Damadin, who 1st discovered the basis of MRI, designed the Stand-up MRI

What makes Medica Stand Up different?

·         Only one in the state
·         Positional scanning: flexibility of scanning sitting, standing, lying down, reclined and even bending and flex/ext views of the spine (i.e.) pt back really hurts when they bend over we can image that
·         Weight-bearing scans – No other MRI can offer
·         Comfort: It is truly open, great for claustrophobic people and watch TV
·         Accommodates up to a 500LB pt and 60 inch waist
·         Important for your Doc: stronger than most open MRIs around .6 vs. .2 tesla


  • No real advantages to getting MRI early
  • Obviously need to have a problem first
  • If you do have a problem go ahead and see the doctor and don’t fear an MRI
  • Putting it off could make it worse
  • MRIs aren’t as scary as they used to be:  come sit and watch TV with us!

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