Technegas: A medical application of 99mTc for the study of buckyballs, blood clots, lung disease and AIDS

Radionuclide studies of lung disease have been greatly enhanced by the introduction of an Australian invention; the Technegas generator. The properties of the open-quotes dry radio-aerosolsclose quotes produced by this device ensure lung images superior to those from true radio-gases such as 133Xe with the additional advantage of employing 99mTc, the most widespread radionuclide agent. A Technegas lung scan can enable identification of pulmonary mebolism (an immediately life threatening condition) emphysema and chronic obstructive lung disease. A simple modification to the generator gas mixture produces Pertechnegas an agent useful in studies of the integrity of the alveolar epithelial membrane in immunosuppressed patients such as transplants and AIDS. Although these agents are now common in Australia and Europe, little has been proven of their chemical composites. Technegas is formed by the initial evaporation of (99mTc) sodium pertechnetate with the subsequent sublimation of carbon from a disposable graphite crucible at ∼2500 degrees C in an atmosphere of 100% argon. 99mTc atoms are lifted off with the crystalline layers of graphite during the vaporization. Technegas then possibly consists of 99mTc based metallo-fullerenes and fullerenes. Technegas has an effective half life in the lung very similar to the physical half life of Technetium (6 hours) regardless of clinical condition; a result which suggests that Technegas contains endohedral fullerenes. Pertechnegas is created in an atmosphere of 97% Ar 3% O2 and has an effective half life in the lung of less than 15 minutes