Abstract
Pulse sequences which permit imaging and volume-selective determination of parameters characterizing the frequency dependence of the spin-lattice relaxation time in the rotating frame, T are presented. The contrasts are due to slowly moving macromolecules or paramagnetic contrast agents. In vivo test experiments were carried out with tumorous mice treated with a contrast agent. It is shown that the contrast effect is dramatically enhanced in T dispersion images compared with images weighted by any of the relaxation times. © 1989 Academic Press, Inc.