Effect of acute lung injury on the spatial correlation of regional pulmonary blood flow

摘要

Abstract: We reanalyzed regional pulmonary blood flow (PBF) and lung water concentration (LWC) data obtained by positron emission tomography to calculate the spatial correlation, p(d), among picture elements (pixels) as a function of distance. Animals were studied in the supine position. Data were obtained both at baseline and after oleic acid induced acute lung injury. With this new analytical approach, we confirmed that p(d) for PBF is strongly positive for adjacent regions but values fall off steadily, reaching strong negative values, at the greatest distances measured. Acute lung injury affected the relationship between p(d) and distance, with less negative correlation at greater distances when perfusion redistribution occurred after injury. However, the magnitude of this effect was not great. The relationship between p(d) and distance for LWC was similar to that observed for PBF, but lung injury caused more, not less, negative correlation at greater distances. Since the relationship between p(d) and distance does not seem to be very sensitive to changes in perfusion distribution, better descriptors of regional heterogeneity are still needed. !16