title: Measurement of pulmonary epithelial permeability with 99mTc-DTPA aerosol.
abstract: The rate at which inhaled aerosol of 99mTc-diethylenetriamine pentaacetate (DTPA) leaves the lung by diffusion into the vascular space can be measured with a gamma camera or simple probe. In normal humans, 99mTc-DTPA clears from the lung with a half time of about 80 minutes. Many acute and chronic conditions that alter the integrity of the pulmonary epithelium cause an increased clearance rate. Thus cigarette smoking, alveolitis from a variety of causes, adult respiratory distress syndrome (ARDS), and hyaline membrane disease (HMD) in the infant have all been shown to be associated with rapid pulmonary clearance of 99mTc-DTPA. Rapid clearance is also promoted by increased lung volume and decreased surfactant activity. Although the mechanism of increased clearance in pathological states is not known, the 99mTc-DTPA lung-clearance technique has great potential clinically, particularly in patients at risk from ARDS and HMD and in the diagnosis and follow-up of alveolitis.
mesh_terms: D000336:Aerosols; D000542:Alveolitis, Extrinsic Allergic / Q000000981:diagnostic imaging; D006207:Half-Life; D006801:Humans; D006819:Hyaline Membrane Disease / Q000000981:diagnostic imaging; D007231:Infant, Newborn; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008176:Lung Volume Measurements; D004369:Pentetic Acid; D011652:Pulmonary Circulation; D011877:Radionuclide Imaging; D012128:Respiratory Distress Syndrome / Q000000981:diagnostic imaging; D012907:Smoking; D013667:Technetium; D016284:Technetium Tc 99m Pentetate
chemical_list: D000336:Aerosols; D013667:Technetium; D004369:Pentetic Acid; D016284:Technetium Tc 99m Pentetate