Radiology, Vol 138, 473-476, Copyright © 1981 by Radiological Society of North America
Measuring pulmonary vascular congestion with quantitative radiographic indexes from digitized images
G Revesz, HL Kundel, PR Lynch and L Toto
Experiments were conducted with the aim of deriving quantitative indexes
from radiographs that describe the status of the pulmonary vasculature
under hypervolemic doncitions. Hypervolemia was induced in four baboons by
the infusion of dextran solution. Left ventricular pressures were monitored
in the erect animals during the infusion and radiographs were obtained. The
radiographs subsequently were digitized with a scanning laser-densitometer
and a PDP 11/40 minicomputer. An index was derived (the vascular complexity
index, Cx), which combined the mean density difference between upper and
lower lung zones (indicative of incipient pulmonary edema) and the ratio of
density variations in the upper versus lower zones (indicative of
redistribution of blood flow). The data indicate a good correlation between
left ventricular and diastolic pressure and Cx during the infusion in each
animal.
