Watanabe N, Inoue T, Tomioka S, Yamaji T, Endo K
Department of Nuclear Medicine, School of Medicine, Gunma University, Japan.
Clin Nucl Med. 1995 Apr;20(4):315-7. doi: 10.1097/00003072-199504000-00006.
Technegas, a newly developed ultra-fine dry dispersion of Tc-99m labeled carbon with a particle size of approximately 5 nm to 20 nm, possesses the properties for lung ventilation imaging using SPECT. The authors observed a discrepancy between krypton-81m gas and technegas lung ventilation SPECT in two patients with idiopathic pulmonary fibrosis who demonstrated heterogeneously decreased distribution of technegas without regions of high count density (focal hot spots) of tracer in their lungs in spite of the almost homogenous distribution of krypton-81m gas. This finding could be explained by the duration of radioactive gas inhalation. Technegas lung ventilation SPECT images reflected lung ventilation with tidal breathing. Conversely, Kr-81m gas lung ventilation SPECT images reflected not only lung ventilation, but also lung volumes. These two radioactive agents for lung ventilation SPECT show different findings.
锝气体（Technegas）是一种新开发的超细微Tc-99m标记碳干分散体，粒径约为5纳米至20纳米，具有用于单光子发射计算机断层扫描（SPECT）肺通气成像的特性。作者在两名特发性肺纤维化患者中观察到，尽管氪-81m气体分布几乎均匀，但锝气体肺通气SPECT显示，这两名患者肺内锝气体分布呈异质性降低，无示踪剂高计数密度区域（局灶性热点）。这一发现可以通过放射性气体吸入的持续时间来解释。锝气体肺通气SPECT图像反映了潮气呼吸时的肺通气情况。相反，氪-81m气体肺通气SPECT图像不仅反映了肺通气情况，还反映了肺容积。这两种用于肺通气SPECT的放射性药物显示出不同的结果。
