¹¹¹In-chloride thorax scintigraphic study for demonstration of pulmonary edema: Canine model

Pulmonary edema induced by injections of oleic acid was demonstrated using ¹¹¹In-chloride lung/heart image in five anesthetized dogs. The anesthetized dogs were positioned under a gamma camera interfaced to a computer. After ¹¹¹In-chloride IV injections, dynamic data were recorded at 1 frame/min before and after induced pulmonary edema. The computer generated the curve of the lung-to-heart activity ratio; the ratio rose from 0.5-0.6 at baseline to 0.85-1.5 at the end of the study in the dogs. At the end of each study, the removed lungs demonstrated edematous fluid, and a few red blood cells were seen in the alveoli. The results indicating pulmonary edema exhibited in the ¹¹¹In-chloride lung-to-heart ratio obtained from a computerized gamma camera were compatable with the pathological results. Since ¹¹¹In-chloride instantly binds to plasma transferrin, an excellent intravascular imaging agent, leakage of this tracer into alveoli indicates loss of membranous wall competence. Pulmonary edema, as in the adult respiratory distress syndrome, is sometimes difficult to diagnose; and this ¹¹¹In-chloride lung-to-heart imaging technique may be potentially useful.