Botelho M f, De Lima J J, Cerqueira M D
Serviço de Biofisica,Faculdade de Medicina,Coimbra,3000, Portugal.
Rev Esp Med Nucl. 1999;18(1):21-31.
Local information on permeability of the alveolar-capillary barrier (PACB) can be ascertained by parametric images, after inhalation of radioarosols and computer processing. Our aim is to compare the results of 99mTc-HMPAO aerosols on PACB studies with those of 99mTc-DTPA aerosols, a standard technique. We compared the two techniques in separate samples: normal controls and patients with severe lung interstitial pathologies. Perfusion studies using 99mTc-MAA have also been performed in all patients. The aerosols were produced using ultrasound and lowered surface tension solution of 99mTc-HMPAO and 99mTc-DTPA. The time-activity curves (TACs) for every pixel on the lung area were used to calculate the half-disappearance times (T1/2). Parametric images were then generated with those times. The comparison of the results obtained with 99mTc-HMPAO and 99mTc-DTPA aerosols suggests that the first ones are more specific for local alterations of the lung epithelial transport in the pathologies studied. This method distinguishes between permeability deficiency due to local perfusion decrease and ACB deterioration.
吸入放射性气溶胶并经计算机处理后，可通过参数图像确定肺泡-毛细血管屏障（PACB）通透性的局部信息。我们的目的是将99mTc-HMPAO气溶胶用于PACB研究的结果与标准技术99mTc-DTPA气溶胶的结果进行比较。我们在不同样本中比较了这两种技术：正常对照者和患有严重肺间质病变的患者。所有患者均进行了使用99mTc-MAA的灌注研究。气溶胶通过超声以及降低99mTc-HMPAO和99mTc-DTPA表面张力的溶液产生。利用肺区域每个像素的时间-活性曲线（TAC）来计算半消失时间（T1/2）。然后用这些时间生成参数图像。99mTc-HMPAO和99mTc-DTPA气溶胶所得结果的比较表明，前者对于所研究病理状态下肺上皮转运的局部改变更具特异性。该方法可区分因局部灌注减少导致的通透性不足和ACB恶化。
