The present invention refers to a method for magnetic resonance imaging or nuclear magnetic resonance spectroscopy comprising emitting a radio frequency and gradient pulse sequence towards an object being subjected to a magnetic field, wherein said object comprises a molecule having an atom with a nuclear spin differing from 0, encoding, detecting and acquiring a magnetic resonance signal from said object corresponding to said emitted radio frequency and gradient pulse sequence, wherein the radio frequency and gradient pulse sequence comprises a first weighting block, a mixing block with duration tm and a second weighting block, and wherein encoding, detecting and acquiring the magnetic resonance signal from said object is limited to initial decay of the signal intensity I with increasing strength of at least one of the first weighting block and the second weighting block, wherein the variation of the initial signal decay rate with tm is analysed to obtain the apparent exchange rate AXR.