The use of iron and gadolinium chelates as NMR contrast agents: animal and human studies.

Rapid development of paramagnetic NMR contrast agents has occurred over the past 3 years. Useful agents include chelates of iron and gadolinium. Gadolinium-DTPA was used safely in 23 human subjects with brain tumors, hepatic tumors and cysts, and a variety of abdominal and pelvic tumors. Various patterns of contrast-enhancement were noted. These agents can radically alter NMR image contrast. Optimum doses, pulse sequences and timing of imaging remain to be determined.