MRI is an important technique in diagnostic clinical imaging owing to its exceptional spatial and anatomical resolution. But the presence of an external agent is necessary to generate contrast. The traditional Gd(III)-based contrast agents are able to generate contrast as they short the relaxation times of water protons where they are distributed. However, some diseases related to this ion have been reported. This has drawn the attention of many researchers, including us, to transition metals ions in order to get safer contrast agents.
A different approach to contrast enhancement is based on chemical exchange saturation transfer with paramagnetic ions (PARACEST), which relies on dynamic chemical exchange processes to get contrast in MRI.