James J M, Testa H J
Department of Nuclear Medicine, Manchester Royal Infirmary, UK.
Nucl Med Commun. 1995 Oct;16(10):802-10. doi: 10.1097/00006231-199510000-00002.
Pulmonary embolism remains a major cause of morbidity and mortality, being responsible for an estimated 200,000 deaths per annum in the USA and 21,000 per annum in the UK. Lung scintigraphy is in many instances the investigation of choice in suspected pulmonary thromboembolism. A normal perfusion lung scan excludes pulmonary embolism. An abnormal perfusion scan, while being sensitive, is of low specificity for the diagnosis of pulmonary embolism and needs to be complemented with a ventilation study. Lung ventilation has been studied using inert gases of radiolabelled aerosols. The new radiopharmaceutical 99Tcm-Technegas is a suspension of 99Tcm-labelled, ultrafine, carbon particles produced in an atmosphere of high-purity argon. The size of the particles is of the order of 0.005-0.2 microns, which assures good peripheral penetration and alveolar deposition. After inhalation, static images in multiple projections may be acquired. The resultant images are of excellent technical quality and several publications have shown the value of Technegas images as an adjunct to perfusion imaging in suspected pulmonary thromboembolism. Studies comparing Technegas images with other ventilatory radiopharmaceuticals have in the majority of instances reported comparable diagnostic qualities.
肺栓塞仍然是发病和死亡的主要原因，在美国每年估计导致20万人死亡，在英国每年导致2.1万人死亡。在许多情况下，肺闪烁扫描是疑似肺血栓栓塞症的首选检查方法。正常的灌注肺扫描可排除肺栓塞。异常的灌注扫描虽然敏感，但对肺栓塞诊断的特异性较低，需要结合通气研究。已经使用惰性气体或放射性标记气雾剂对肺通气进行了研究。新型放射性药物99锝-锝气体是在高纯度氩气环境中产生的99锝标记的超细碳颗粒悬浮液。颗粒大小约为0.005-0.2微米，这确保了良好的外周穿透性和肺泡沉积。吸入后，可获取多个投影的静态图像。所得图像具有出色的技术质量，一些出版物表明锝气体图像作为疑似肺血栓栓塞症灌注成像辅助手段的价值。将锝气体图像与其他通气放射性药物进行比较的研究在大多数情况下报告了相当的诊断质量。
