Aerosol-derived lung morphometry: comparisons with a lung model and lung function indexes.
This study evaluated the ability of aerosol-derived lung morphometry to noninvasively probe airway and acinar dimensions. Effective air-space diameters (EAD) were calculated from the time-dependent gravitational losses of 1-microns particles from inhaled aerosol boluses during breath holding. In 17 males [33 +/- 7 (SD) yr] the relationship between EAD and volumetric penetration of the bolus into the lungs (Vp) could be expressed by the linear power-law function, log (EAD) alpha beta log (Vp). Our EAD values were consistent with Weibel's symmetric lung model A for small airways and more distal air spaces. As lung volume increased from 57 to 87% of total lung capacity (TLC), EAD at Vp of 160 and 550 cm3 increased 70 and 41%, respectively. At 57% TLC, log (EAD) at 160 cm3 was significantly correlated with airway resistance (r = -0.57, P less than 0.0204) but not with forced expired flow between 25 and 75% of vital capacity. Log (EAD) at 400 cm3 was correlated with deposition of 1-micron particles (r = -0.73, P less than 0.0009). We conclude that aerosol-derived lung morphometry is a responsive noninvasive probe of peripheral air-space diameters.
Blanchard
J D
JD
Respiratory Biology Program, Harvard School of Public Health, Boston, Massachusetts 02215.
Heyder
J
J
O'Donnell
C R
CR
Brain
J D
JD
D000328:Adult; D000336:Aerosols; D000403:Airway Resistance; D005652:Functional Residual Capacity; D006801:Humans; D008168:Lung / Q000033:anatomy & histology*; D008176:Lung Volume Measurements; D008297:Male; D008954:Models, Biological; D012129:Respiratory Function Tests; D014109:Total Lung Capacity
D000336:Aerosols