A quantitative study of magnetization transfer in MAGIC gels

Magnetization transfer (MT) has been measured quantitatively as a function of radiation dose in MAGIC polymer gels. The MT rates between the free and immobile macromolecular proton pools (k(mf) and k(fm)), and the ratio of the sizes of these coupled proton pools (p(m)/p(f)), were measured by analysing the response to an inversion recovery sequence. While p(m)/p(f) increases linearly with dose, the fast MT rate k(mf) also increases with dose, unlike previous measurements in BANG gels. This dependence of k(mf) on dose suggests there are additional factors that modify spin exchange in MAGIC gels as irradiation occurs.