Volume of emphysema.

A method of determining the volume of emphysema in excised lungs is presented, with its validation. This method is based on macroscopic point counting using a perforated grid but only the holes (points) overlying emphysema need be counted to produce results within a percentage standard error of 5%. Application of the method shows that an adequate assessment of emphysema cannot be made from one lung slice alone, and that the amount of emphysema found in one lung cannot be used to predict the amount of emphysema in the other lung.