Free induction decay and T2* decay

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Free induction decay

  • Apply an RF pulse, achieve desired resonance and flip angle, then RF pulse is removed
  • Signal induced in receiver coil begins to decrease in amplitude
  • This signal decrease is due to
    • Relaxation
    • Field inhomogeneity and susceptibility

T2* decay

  • Dephasing due to spin-spin interactions and field inhomogeneities together