Abstract

Injured or diseased marine turtles are frequently presented for evaluation and treatment. Diagnosis and treatment of injury and disease in marine turtles present unique challenges. Digital radiology is a useful diagnostic tool in marine turtle medicine. It is generally readily available and provides high quality images that can be viewed almost instantly. Interpretation of images, however, can be difficult. The unique skeletal structures of the carapace and plastron create multiple areas of superimposition, obscuring other skeletal and soft tissue structures. Apart from air-filled structures within the coelom, lack of contrast makes distinction of individual viscera difficult.

Radiology requires the recognition and description of abnormal findings and the interpretation of these findings. In order to recognise abnormalities, knowledge of normal radioanatomy is required. One option for increasing confidence in distinguishing normal from abnormal is to consult reference material on normal radioanatomy. The aim of this study was to produce a guide to normal radioanatomy of the green turtle (Chelonia mydas), aiding localisation of coelomic viscera, and defining appendicular and axial skeletal structures. The study used archived digital radiographs of wild green turtles at Taronga Zoo and computed tomography (CT) scans of two green turtles at Sydney University Diagnostic Imaging Department. Illustrated anatomic overlays were produced using these radiographs and CT images, together with contrast studies, anatomic references, and necropsy specimen photographs. Digital radiographs were imported into design software (Adobe Illustrator) and used to produce 13 illustrated overlays. DICOM software (OsiriX) was used to produce 12 rendered CT images. This guide will provide a valuable resource for interpretation of radiographs of green turtles with potential extrapolation to other marine turtle species.