[摘要]：vasculature for extended periods of time. A new contrast agent is described in which gadolinium is encapsulated within an extremely stable carbon sphere, thus allowing for safe extended residence. Water soly. and small particle size is achieved with novel fullerene chem., attaching multiple oligoethylene glycol groups through nitrogen chem. These new compds. can be used to visualize tissue architecture in vivo with std. MRI techniques.
