Nasolacrimal system aeration on computed tomographic imaging: effects of patient positioning and scan orientation

Abstract

Craig N Czyz,1 Thomas S Bacon,2 Andrew W Stacey,3 Eva N Cahill,4 Bryan R Costin,5 Boris I Karanfilov,6 Kenneth V Cahill5 1Section Oculofacial Plastic and Reconstructive Surgery, Ohio University/OhioHealth, 2Department of Medical Education, Mount Carmel Health Systems, Columbus, OH, USA; 3Department of Ophthalmology, University of Michigan, Ann Arbor, MI, USA; 4Department of Biology, Wittenberg University, Springfield, OH, USA; 5Department of Ophthalmology, William H Havener Eye Institute, Ohio State University Wexner Medical Center, Columbus, OH, USA; 6The Sinus Institute of Ohio, Dublin, OH, USA Purpose: To determine the impact of patient positioning and scan orientation on the appearance of air in the nasolacrimal drainage system on computed tomography (CT) imaging, and the repeatability of the observations.Methods: This was a retrospective analysis of CT images for 92 patients.Results: Air was found to be present more fully in the upright-position group as compared with the supine-position group. Comparing axial and coronal scan orientation, no difference in aeration was found, except for the nasolacrimal duct in the upright-position group.Conclusion: Patient position should be accounted for in diagnostic conclusions and treatment decisions based on CT. Keywords: axial, coronal, nasolacrimal sac, nasolacrimal duct