LUNG VENTILATION AGENTS

Xe-133, most commonly used, Xe-127, t = 36.4 days; photons @ 172, 203, 375 keV, can image V after Q, Kr-81m, very expensive, t = 13 sec; photon 190 keV, can repeat V in every projection, Tc-99m DTPA aerosol, can image V in mult. Projections, image Q after V, 1 mCi most likely to be 50-75 mrad to lung, V/Q imaging

electron transport chain electron transport particles electron transport phosphorylation electron transport system electron velocity electron-volt electron wavelength electronystagmogram (0)