Figure 1.

Schema for the process of quantitating mean linear intercept. (A) Hematoxylin and eosin stained lung tissue section as an example of the digital images obtained for analysis. (B) A binary image of the photomicrograph converted by a macro program. (C) The binary alveolar structure is next reduced to a skeletonized structure one pixel in width. (D) A series of probe lines are superimposed on the skeletonized image and points where the alveolar structure intercepts the probes are recorded and exported. Mean linear intercept equal total probe length divided by number of intercepts.