Quantitative analysis of radioaerosol inhalation and perfusion scintigraphy in dogs.

A method was developed for the analysis of 99mTc MAA perfusion and 99mTc phytate colloid aerosol inhalation distribution patterns. Scintigraphic images were compared, based on the activity of corresponding picture elements (pixels). The possible mismatching in a pixel between both distributions was expressed in terms of a regional mismatching (common to a whole region) and an additional intraregional mismatching at the individual pixel level. Parameters characterizing the degree of regional and intraregional mismatching were introduced. The method was applied to 16 anesthetized healthy dogs in which a cranial-to-caudal gradient in regional mismatching was found.