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iron oxide particles illustration
    
  Appears In
      
      NIST’s Ultra-small, Shape-shifting GEMS Offer an Easier and Cheaper way to improve MRI Imaging
      
            When placed in a strong external magnetic field (labeled M), the iron oxide particles become magnetized, causing the microparticles to develop their own local magnetic field. The microparticles shrink and swell with changes in acidity, which strengthens or weakens this local field and therefore how much the field influences the resonant frequency of protons during an MRI scan.

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