Computed tomography for evaluation of the normal lung in adult male terrapins of five captive species

ABSTRACT Data on the tomographic characteristics of lung parenchyma in terrapins are rare. The objective of this study was to describe the tomographic anatomy of the lung parenchyma in five species of terrapins and estimate the normal CT attenuation values of the lungs, expressed in Hounsfield Units (HU). Fifty animals from five different species of Brazilian terrapins (Kinosternon scorpioides - Scorpion mud turtle, Mesoclemmys tuberculata - Tuberculate toad-headed turtle, Podocnemis expansa - Giant South American turtle, Podocnemis unifilis - Yellow-spotted Amazon River turtle, Trachemys dorbigni - Black-bellied slider turtle) were selected for computed tomography scans. Mean ± SD lung CT attenuation values were obtained for each terrapin from dorsal multiplanar reconstruction images. All animals had two lungs with similar anatomic limits and reticular aspect without a bronchial tree. Overall, mean ± SD attenuation for the lung parenchyma was -813.28 ± 22.16 HU for all species. There was no significant difference between the species. In conclusion, this study provides the tomographic anatomy and mean lung attenuation in Hounsfield Units (HU) values for each of the five studied species, providing basic reference values for future studies in these terrapins.