A new experimental model has been developed to determine whether computed tomography has any advantages for the investigation of lung contusions. In 27 dogs, chest wall deformation was produced at speeds varying from 17.3 m/sec to 45.7 m/sec, leading to lung contusion. After the injury, 27 out of 27 (100%) CT examinations demonstrated the contusions, but only nine out of 24 (37.5%) were seen on conventional radiographs. In contrast to conventional radiography, which either failed to show the presence of a contusion, or which under-estimated the extent by more than one cm, in more than half the cases CT agreed with the pathological findings in more than 90%. No lung contusions were found at autopsy which had not been demonstrated by CT.
After breathing pure oxygen, total atelectasis of one lung was produced in ten dogs; its development and regression was followed by CT and by conventional radiology. 30 seconds after cessation of ventilation, it was possible to show a rise in CT density of the atelectatic lung from -764 +/- 32 HU to -739 +/- 49 HU. The average time from the cessation of ventilation to total atelectasis averaged 5.5 +/- 1.1 minutes. The earliest sign on conventional radiographs was often seen after 30 seconds and usually after 60 seconds and consisted of mediastinal displacement. Extensive atelectasis regressed in only one out of six animals within one hour after resuming ventilation. The experimental methods and results and the significance of the physiological findings in a clinical context are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.