MRI: What is Gyromagnetic Ratio?
In Magnetic Resonance Imaging (MRI), one of the important factors considered is the Gyromagnetic Ratio (also known as the magnetogyric ratio) of a particle or system. Gyromagnetic ratio is the ratio of its magnetic dipole moment to its angular momentum, and it is often denoted by the gamma symbol (γ). The SI units of Gyromagnetic ratio are radian per second per tesla (rad/s/T) or, equivalently, coulomb per kilogram (C/kg). It is also defined as the ratio of the resonance frequency to the magnetic field strength for a given nucleus.
Gyromagnetic ratio has a constant value for any given nucleus that relates the nuclear MR frequency and the strength of the external magnetic field. It represents the ratio of the magnetic moment (field strength) to the angular momentum (frequency) of a particle. The value of the gyromagnetic ratio for hydrogen (1H) is 4,258 Hz/Gauss or (42.58 MHz/Tesla).
Below are the constant values of Gyromagnetic Ratio for other nuclei.