Abstract: A method and system for measuring the macromolecular proton concentration involved in magnetization transfer comprising the steps of applying a first RF pulse of flip angle ?1 at a first time, applying a first magnetic field gradient along a predetermined direction, applying a second RF pulse of flip angle ?2 at a second time ?1 seconds after said first time, applying a third RF pulse of flip angle ?3 at a third time ?1+?2 seconds after said first time, applying a fourth RF pulse of flip angle ?4 at a fourth time ?1+?2+?3 seconds after said first time, applying a second magnetic field gradient along the same pre-determined direction as said first magnetic field gradient, and detecting a stimulated echo at a fifth time.