This study was initiated to determine the rate and characteristics of 99Tc-DTPA clearance from the whole lung in a group of 9 sheep. Submicronic aerosol droplets were delivered to unsedated sheep held in sing-like frame. Best fits for clearance to single- and bioexponentials were calculated. The monoexponential T50 for the aerosol clearance was 293 in ± 74 SD. Background correction was found to have a minimal effect (approx. 10%). Bioexponential fitting only marginally improved correlations in the 8 healthy sheep, but in one additional animal with clinical evidence of pneumonia, clearance was faster and biexponential fitting was substantially better. These clearance values in conscious sheep are longer than previous findings mwith 99mTc-DTPA in anesthetized sheep. There appears to be a wide variation of radioaerosol 99mTc-DTPA lung clearances among different species, sheep exhibiting a comparatively prolonged clearance profile.
- Bronchoalvelor clearance
- Respiratory epithelial permeability
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine