The particle size distribution of technegas and its influence on regional lung deposition.

The size distribution of the aerosol produced by a technegas generator has been measured with a screen diffusion battery. The median diameter of the active aerosol was found to be of the order 140 nm and not to vary with the delay between generation and use. The measurements indicate that about 20% of the aerosol should be deposited in deep lung with about 5% deposited in the upper airways.