chemical shift

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chem·i·cal shift

dependence of the resonance frequency of a nucleus on the chemical binding of the atom or molecule in which it is contained. See: chemical shift artifact.

chemical shift

(in nuclear magnetic resonance spectrometry) the position of a resonance in the substance of interest relative to the position of the resonance of a standard. Nonequivalent atoms of a molecule have different chemical shifts.

chemical shift

An MRI term for a variation in the nominal Larmor frequency for a particular isotope within the imaging volume. The amount of chemical shift is directly proportional to the strength of the magnetic field, and is specified in parts per million of the resonant frequency.