Digital photogrammetric quantification of surface area and volume on scanning electron micrographs of frozen hydrated lung tissue

A digital video plotter (DVP, Leica), the personal computer equivalent of an analytical plotter, was used to measure the coordinates of points chosen from stereo pair images of the surface of frozen hydrated lung imaged at magnifications of 2000 and 5000 X with a low-temperature scanning electron microscope (SEM). Rat lung tissue was frozen in vivo with a liquid nitrogen cryoprobe under carefully controlled physiologic conditions. At slow …