Application of the Cavalieri principle and vertical sections method to lung: estimation of volume and pleural surface area

TLDR

The study proposes a practical, unbiased stereological methodology for estimating lung volume with Cavalieri's principle and pleural surface area via vertical sections. The design samples extensive slices and vertical sections for light and electron microscopy, with procedures illustrated on right lungs of four rabbits and detailed statistical analysis of biological, systematic, and point‑counting variation. Lung volume estimates from Cavalieri's principle agreed excellently with fluid displacement measurements.

Abstract

SUMMARY A practical methodology is proposed for the stereological analysis of lung and other organs using recently developed unbiased procedures. This study concentrates on the unbiased estimation of lung volume using Cavalieri's principle compared with the fluid displacement method and measurement of pleural surface area using vertical sections. Furthermore, the proposed design, in addition to the sampling of extensive slices for the initial steps, also allows sampling of vertical sections for light and electron‐microscopical stereology. The procedures are described in detail by reference to biological data from the right lungs of four rabbits. We found excellent agreement between estimates of lung volume measured with Cavalieri's principle and those measured by fluid displacement. Pertinent details of the statistical analysis of the sources of variation (namely biological, systematic sectioning and point‐counting variation) are given in an appendix.