Definition of MRI in US English:

MRI

noun

Medicine
  • 1

    ‘the researchers used MRI to record the brain activity’
    1. 1.1 A medical examination performed using magnetic resonance imaging.
      ‘he's having an MRI to determine the extent of the injury’
    2. 1.2 An image obtained by magnetic resonance imaging.
      ‘after looking at the MRI, the doctors concluded that she needed surgery’

Pronunciation

MRI

/ˌemˌärˈī//ˌɛmˌɑrˈaɪ/