Morphometry of experimental lung contusion: an improved quantitative method.

Alterations of lung tissue following pulmonary contusion are mainly assessed qualitatively. Quantitative examinations were limited up to now, to investigations in X-ray and computer tomography images, since morphometry of contused and normal biotic lung tissues seemed to be methodologically unfeasible. In order to overcome this shortcoming, the lungs of pigs were examined after unilateral lung contusion. In semithin sections, the thickness distribution of the interstitium and the volume distribution of the alveolar cavities were studied. Using an image analysis system a sequence of detection, erosion and skeletonisation steps were used to recognize the septal tissue correctly. The percent distributions were calculated from chord measurements after a sequence of erosion steps. It turned out that this technically simple procedure enabled highly reliable and valid results to be obtained, concerning the morphometric analysis of the alterations in the contused, as well as in the non-injured lungs.