Computed Tomography, Magnetic Resonance Imaging and Gross Cross-Sectional Views of the Normal Anatomy of the Koala (Phascolarctos cinereus) Nasal Cavity and Paranasal Sinuses
Knowledge of the normal anatomy of the nasal cavities and paranasal sinuses of the koala (Phascolarctos cinereus) is important in the diagnosis of nasal disease, including cryptococcosis, nasal polyps, and neoplasia.1 Computed tomography (CT) and magnetic resonance imaging (MRI) are useful tools in diagnosing abnormalities of the nasal cavities and paranasal sinuses and for planning surgical intervention.2 This study compared gross anatomic sections with CT and MRI images in order to describe the normal appearance of the koala nasal cavity and paranasal sinuses. Three deskinned koala skulls were transected at approximately 10 mm intervals in transverse, sagittal, and dorsal planes prior to being photographed. A clinically normal koala was anesthetized for acquisition of dorsal plane CT scan images of its nasal cavities and paranasal sinuses. Sagittal and transverse plane images were reformatted from the dorsal plane scans. A second koala underwent the same procedure for MRI images acquisition. The MRI and CT images obtained were matched with the corresponding gross anatomic images and the normal bone, tissues and airway passages were identified. The resulting comparative images can be used to aid diagnosis, plan surgical intervention, and monitor therapeutic responses of diseases of the nasal cavity and paranasal sinuses of the koala.
This study was approved by the San Diego Zoo Global Institutional Animal Care and Use Committee (Proposal #11-029). San Diego Zoo Global has an Animal Welfare Assurance (A3675-01) on file with the Office of Laboratory Animal Welfare.
1. Bercier, M., J. Wynne, S. Klause, C.K. Stadler, A. Gorow and G.W. Pye. 2012. Nasal mass removal in the koala (Phascolarctos cinereus). J Zoo Wildl Med. 43:898–908.
2. Saunders J. and T. Schwarz. 2011. Nasal cavities and frontal sinuses. In: Schwarz T. and J. Saunders (eds.). Veterinary Computed Tomography. John Wiley & Sons Ltd, Chichester, West Sussex, UK. Pp 93–109.