Radiology, Vol 186, 423-426, Copyright © 1993 by Radiological Society of North America
Experimentally produced pulmonary arterial occlusion in the dog: identification with pertechnegas inhalation
EM Scalzetti, ZD Grossman and GM Gagne
Department of Radiology, State University of New York, Syracuse 13210.
Pertechnegas, a variant of technegas, is a fine, dry aerosol formed when
technetium-99m pertechnetate is vaporized in a technegas generator under
appropriate conditions. After inhalation, the aerosol is deposited almost
entirely on the surfaces of terminal respiratory structures. Unlike
technegas, however, pertechnegas crosses the alveolar-capillary membrane
and leaves the lung through the pulmonary circulation. To demonstrate
prolonged retention of pertechnegas in regions of lung supplied by an
occluded pulmonary artery, 12 pulmonary arterial occlusions were
experimentally produced in two dogs. After inhalation of pertechnegas, a
transient focus of increased pulmonary radioactivity was seen in 11
occlusions; 10 of these 11 foci were easily confirmed by means of
subsequent perfusion scintigraphy. All 11 foci of retained pertechnegas
corresponded to the location of the non- perfused lung. Thus, it is
possible to identify ischemic lung with focal retention of pertechnegas (a
finding that indicates preserved ventilation but diminished perfusion) by
use of a single examination.
