1) The specific irradiation designed to remove the multiple structure in a particular resonance due to spin spin coupling with other nuclei;
2) The preventing of the interaction by mutual inductive coupling of two (or more) resonant RF coils, e.g. by detuning coils not in use at a particular point in time. Decoupling can take the form of active decoupling where an externally controlled switching circuit is used to detune the non-selected coils or passive decoupling where RF energy from the transmitter pulse is used to switch diodes to detune the appropriate coil.

(NOE) A change in the steady state magnetization of a particular nucleus due to irradiation of a neighboring nucleus with, which it is coupled by means of a spin spin coupling interaction. This interaction must be the primary relaxation mechanism of these nuclei. Such an effect can occur during decoupling and must be taken into account for accurate intensity determinations during such procedures.

A semiconductor device whose RF resistance varies in proportion to an applied DC bias current. PIN diodes are essential elements for rapid switching of RF coils between transmit and receive modes and for coil decoupling.