Xenon contrast enhancement in computed body tomography

Xenon has been investigated as a contrast medium for conventional radiography, and in vitro as a contrast medium for computed tomography. The authors evaluated xenon contrast enhancement in vivo for CT body scanning. Nine healthy subjects had CT scans before and during xenon inhalation. Concentrations of xenon used varied from 10--50%. Consistent useful changes in attenuation from inhaled xenon were found in the lung but not in abdominal organs. Lung attenuation varied linearly with the xenon concentration in the inhaled gas. Inhalation of xenon concentrations greater than 30% resulted in side effects. Further studies are required to demonstrate whether xenon contrast enhancement is of diagnostic value in computed tomography.