Final answer:
Gadolinium contrast should be administered as a stable complex with DTPA to avoid toxicity and ensure excretion by the kidneys, thereby providing detailed MRI images of soft tissues.
Step-by-step explanation:
Following the administration of IV gadolinium contrast, it is recommended to ensure that the gadolinium is administered as a very stable complex to prevent toxicity. The toxic aqueous ion Gd3+ (aq) is highly paramagnetic with seven unpaired electrons, making it suitable for use in MRI contrast agents due to its impact on the magnetic properties of water in cells. However, because Gd3+ (aq) is toxic, it is crucial that it is bonded to complexing agents like DTPA5− (diethylene triamine pentaacetic acid) that do not dissociate in the body and can be excreted intact by the kidneys. This allows for more detailed and contrasting images of soft tissues in an MRI scan, which would otherwise be difficult to obtain due to the similar magnetic properties of water inside and outside of cells.