Mucociliary clearance and pulmonary epithelial permeability of normal and acute bronchitic rabbits measured by three-dimensional pet and rectilinear scan after inhalation of 2-[¹⁸F]fluoro-2-deoxy-D-glucose

Mucociliary clearance and pulmonary epithelial permeability of acute bronchitic rabbits were simultaneously evaluated using three-dimensional positron emission tomography and rectilinear scan after inhalation of 2-[ ¹⁸F]fluoro-2-deoxy-D-glucose (¹⁸FDG) solution and compared to those of normal rabbits. The pulmonary epithelial permeability constant was obtained from the decline in the amount of the¹⁸FDG radioactivity with time in the region of interest (ROI) 1 confined to the collection tube of respiratory tract fluid, tracheal cannula, trachea and lungs in the whole body rectilinear scan. Total elimination constant in the lungs was obtained by time-dependent elimination of the radioactivity in the whole lung tomographic scans. The mucociliary clearance rate of the lungs was obtained by the subtraction of the pulmonary epithelial permeability constant from the total elimination constant in the lungs. The total elimination rate of the lungs and the blood radioactivity level in the subacute bronchitic rabbits were greater than those of normal rabbits. The mucociliary clearance rate in the trachea of impaired rabbits was markedly low compared to that of normal rabbits. The mucociliary clearance rate of the lungs was not successfully comparable between normal and acute bronchitic rabbits, because the initial deposition ratio of¹⁸FDG in the trachea, main bronchi and lungs was significantly different between normal and bronchitic rabbits. However, the pulmonary epithelial permeability and the mucociliary clearance rates could be simultaneously examined in the whole lung positron emission tomography and rectilinear scan, and then the efficacy of the drugs should be evaluated within the same conditioned rabbits.