title: The effect of positioning on the radiographic appearance of caudodorsal mediastinal masses in the dog.
abstract: In this prospective study, the effect of thoracic positioning on the visibility and size of caudal esophageal masses caused by spirocercosis was investigated. Dorsoventral (DV), ventrodorsal (VD) as well as left lateral recumbent (LLR) and right lateral recumbent (RLR) thoracic radiographs of 28 dogs, diagnosed endoscopically with spirocercosis, were evaluated. The radiographic findings were compared with those of esophageal endoscopy. Masses were seen equally well in left vs. right recumbency as well as in DV vs. VD positions but in DV/VD views 86% of masses were detected whereas in lateral views only 50% of masses were identified. In spirocercosis-endemic areas DV and RLR views are advised as they also allow for better visualization of descending aorta aneurysms and to avoid interpreting the potentially normally visible esophagus in LLR in large dogs as a mass.
authors.affiliation: Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort 0110, Pretoria, South Africa. robert.kirberger@up.ac.za
authors.forename: Robert M
authors.initials: RM
authors.lastname: Kirberger
authors.forename: Eran
authors.initials: E
authors.lastname: Dvir
authors.forename: Liesel L
authors.initials: LL
authors.lastname: van der Merwe
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000469:parasitology; D004285:Dogs; D004724:Endoscopy / Q000662:veterinary; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000469:parasitology / Q000662:veterinary*; D056888:Patient Positioning / Q000662:veterinary*; D011187:Posture; D011446:Prospective Studies; D013902:Radiography, Thoracic / Q000379:methods / Q000662:veterinary*; D017205:Spirurida Infections / Q000000981:diagnostic imaging / Q000662:veterinary; D013802:Thelazioidea