IN-VIVO NMR AND MRI USING INJECTION DELIVERY OF LASER-POLARIZED XENON

Because xenon NMR is highly sensitive to the local environment, laser- polarized xenon could be a unique probe of living tissues. Realization of clinical and medical science applications beyond lung airspace ima ging requires methods of efficient delivery of laser-polarized xenon t o tissues, because of the short spin-lattice relaxation times and rela tively low concentrations of xenon attainable in the body. Preliminary results from the application of a polarized xenon injection technique for in vivo Xe-129 NMR/MRI are extrapolated along with a simple model of xenon transit to show that the peak local concentration of polariz ed xenon delivered to tissues by injection may exceed that delivered b y respiration by severalfold.