Cook G, Clarke S E
Department of Nuclear Medicine, Guys Hospital, London, UK.
Eur J Nucl Med. 1992;19(9):770-4. doi: 10.1007/BF00182818.
A ventilation agent that provides good quality lung images, which is cheap, easy to use and non-toxic, with a low radiation dose, has long been sought. Technegas, an ultrafine aerosol of technetium-99m-labelled carbon, was developed with these qualities in mind. We have studied Technegas in a clinical setting to evaluate some of these qualities. Twenty-five patients referred with a diagnosis of suspected pulmonary embolism were investigated during the same study using both krypton-81 m and Technegas as ventilation agents in conjunction with 99mTc-macroaggregated albumin as a perfusion agent. Technegas provided images which were of satisfactory quality. Images were obtained relatively easily and without discomfort to the patient, and Technegas has the advantage of always being available. A semi-quantitative regional assessment was employed which showed a good correlation (r = 0.499, P less than 0.001) between Technegas and krypton-81 m ventilation. We report on an effect not previously found to be significant, that is lung regions were better ventilated with Technegas than with krypton-81 m. This altered the diagnostic probability rating of pulmonary embolism in a number of patients (n = 3, 12%) compared with krypton-81 m. This effect was also noted in a further 8 patients (32%) without a change in the diagnostic probability. We offer possible explanations for this phenomenon.
长期以来，人们一直在寻找一种能提供高质量肺部图像、价格低廉、使用方便、无毒且辐射剂量低的通气剂。基于这些特性开发了锝-99m标记碳的超细微粒气溶胶Technegas。我们在临床环境中对Technegas进行了研究，以评估其中的一些特性。在同一项研究中，对25名被诊断为疑似肺栓塞的患者进行了检查，同时使用氪-81m和Technegas作为通气剂，并结合99mTc-大聚合白蛋白作为灌注剂。Technegas提供的图像质量令人满意。相对容易地获得了图像，且患者没有不适感，并且Technegas具有随时可用的优势。采用了半定量区域评估，结果显示Technegas与氪-81m通气之间具有良好的相关性（r = 0.499，P小于0.001）。我们报告了一种以前未发现具有显著意义的效应，即与氪-81m相比，Technegas使肺部区域通气更好。与氪-81m相比，这改变了一些患者（n = 3，12%）肺栓塞的诊断概率评级。在另外8名患者（32%）中也观察到了这种效应，但诊断概率没有变化。我们对这一现象提供了可能的解释。
