Comparison of orbital volume measured using computed tomography and fluid displacement: A comparative study using dry skull

Abstract

Objectives: The purpose of the study was as follows: (1) To compare orbital volume calculated using computed tomography (CT) scans with real-time measurements. (2) To evaluate if the orbital volume of the adjacent orbit can be taken as a tool of comparison for orbital volume correction in orbital fractures. Materials and Methods: A prospective study was conducted on 30 orbital cavities with intact orbital walls. The foramina and fissures were sealed using molding wax. Alginate impressions of the orbital cavity were taken to determine the orbital volume using the Archimedes principle. GE light speed 64 slices CT scanner was used to scan the orbits with 0.8 mm sections. Orbital volume was calculated using the CT software GE ADW 4.5 workstation. Results: The comparison of CT measurement and Archimedes principle measurement shows a mean and standard error of 0.2333 mm and 0.09794, respectively, on the right orbits and a mean and standard error of 0.10011 mm and 0.0981, respectively, on the left orbits. The comparison of the right and left orbits shows a mean and standard error of 0.4067 mm and 0.2771 mm, respectively, using the Archimedes principle and a mean and standard error of 0.3300 mm and 0.2775, respectively, using CT scans. Conclusion: It was found that the difference in orbital volume between CT and real-time measurement is very negligible. The study shows that CT is a reliable tool for the orbital volume measurement and the adjacent orbit can be taken as a comparative tool for the orbital volume corrections.