IMAGE-ANALYSIS OF HEMOSIDERIN-LADEN MACROPHAGES IN BRONCHOALVEOLAR LAVAGE FLUID

The aim of this study was to assess quantitatively the relationship be tween the number of iron-laden macrophages, extent of hemosiderin cont ent and amount of dark-stained hemosiderin clumps in bronchoalveolar l avage (BAL) fluids. The series included specimens from 20 subjects who se BAL had yielded iron-laden macrophages. Six had developed hemoptysi s 3-15 days prior to BAL. Quantitative studies were performed on smear s stained by the ferrocyanide reaction, using true color image analysi s for image segmentation. A top-hat-function based on mathematical mor phologic concepts was used for extraction of dark clumps of hemosideri n. The results demonstrated the presence of iron-laden macrophages thr ee days after hemoptysis. There was a moderate correlation between the percentage of macrophages and amount of hemosiderin content, but the extent of dark-stained clumps did not increase in parallel to the incr ease in hemosiderin content and probably represented an advanced stage in the phagocytic processing of hemosiderin formed from engulfed red blood cells. The main difference between subjects with and without pre vious hemoptysis was higher values for dark clumps of hemosiderin in t he former.