Fig. 4

Schematic overview of the magnetization transfer (MT) mechanism. A series of high flip-angle off-resonance (Δω) RF pulses, followed by a spoiler gradient, are performed to selectively saturate the bound proton pool (macromolecules or MM). Since the bound proton pool and free proton pool (water molecules) are in continuous exchange with each other (curved arrows), magnetization is transferred from the free to the bound proton pool, leading to a decrease in net magnetization for the free proton pool and thus also in the detected signal. ω₀ = Larmor frequency