The present invention describes methods and compositions for non-invasively assessing the molecular structure of biocompatible hydrogels using MRI analysis. It is shown that biocompatible hydrogels prepared from polymerizing macromolecules that are attached to a paramagnetic, superparamagnetic or ferromagnetic contrast agents form reporter gels wherein monitoring of the changes in the structure of the hydrogels by MRI is facilitated by the presence of such paramagnetic, superparamagnetic or ferromagnetic agents in the biocompatible hydrogel.