In<unk>  (that is 'in the living organism') magnetic resonance spectroscopy (MRS) is a specialised technique associated with magnetic resonance imaging (MRI).
In vivo magnetic resonance spectroscopy
Nuclear magnetic resonance spectroscopy
Near infrared spectroscopy
Biological small-angle X-ray scattering
Electromagnetic spectrum
Pressure volume diagram
Infrared spectroscopy
Functional magnetic resonance imaging