Study of diffusion coefficient of hyperpoalrized gases and their use as a contrast agent in MRI.

L. AGULLES-PEDRÓS; R. H. ACOSTA; P. BLÜMLER; J. SCHMIEDESKAMP; H.W. SPIESS

Tarragona, España

Congreso; EUROMAR Magnetic Resonance Meeting; 2007

The use of MRI as diagnostic tool is increasingly employing functionalcontrast agents to study or contrast entire mechanisms. Contrast agents in MRI canbe classified in two categories. One type of contrast agents alters the NMR signal ofthe protons in its surrounding, e.g. lowers the T1 relaxation time. The other typeenhances the NMR signal of specific nuclei. For hyperpolarized gases the NMRsignal is improved several orders of magnitude. The most interesting question inspatially resolved experiments is of course the achievable resolution and contrast bycontrolling the diffusivity of the gas. However, gases have a high diffusivity whichstrongly influences the NMR signal strength, hence the resolution and appearance ofthe images.