COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE FOR THE ADVANCED IMAGING OF THE NORMAL NASAL CAVITY AND PARANASAL SINUSES OF THE KOALA (PHASCOLARCTOS CINEREUS)

Abstract

The objective of this study is to describe computed tomography (CT) and magnetic resonance (MR) for the cross-sectional imaging of the normal anatomy of the nasal cavity and paranasal sinuses of the koala (Phascolarctos cinereus), to provide reference figures for gross anatomy with corresponding CT and MR images and to compare the features of the nasal cavity and paranasal sinuses of the normal koala with that reported in other domestic species. Advanced imaging can be used to aid in diagnosis, to plan surgical intervention, and to monitor therapeutic responses to diseases of the nasal passages in koalas. One clinically normal koala was anesthetized twice for the separate acquisition of dorsal CT scan images and transverse, dorsal, and sagittal MR images of its nasal cavity and paranasal sinuses. Sagittal and transverse CT planes were reformatted. Three fresh koala skulls were also transected in one of each transverse, sagittal, and dorsal planes and photographed. The CT and MR images obtained were matched with corresponding gross anatomic images and the normal bone, tissues and airway passages were identified. All anatomic structures were readily identifiable on CT, magnetic resonance imaging (MRI), and gross images. CT and MRI are both valuable diagnostic tools for imaging the nasal cavities and paranasal sinuses of koalas. Images obtained from this project can be used as baseline references for future comparison with diseased koalas to help with diagnosis, surgical intervention, and response to therapy.

Correlation between Cross-Sectional Anatomy and Computed Tomography of the Normal Six-Banded Armadillo (Euphractus sexcintus) Nasal Cavity and Paranasal Sinuses

“…To the best of the authors' knowledge, this is the first description of this region in the sixbanded armadillo using anatomical cross-sections and conventional CT equipment. Similar studies accomplished on a variety of species, such as rhinoceros iguanas [12], horses [27,29], dogs [28,34], koalas [31], rabbits [32], and guinea pigs [33], have effectively demonstrated that the combination of advanced imaging techniques and anatomical cross-sections is adequate for studying the complex anatomy of this region.…”

“…However, the use of these techniques in exotic animal medicine is currently limited because of their expenses, availability, and the logistic problems of acquiring images of some of these species. Although descriptions of the CT and MRI of the nasal cavities and frontal sinuses have been done in exotic and traditional species, including dogs, horses, sea turtles, rabbits, koalas, guinea pigs, and members of the Dasypodidae family, such as the nine-banded armadillo [12,21,[27][28][29][30][31][32][33][34], a detailed anatomic description of those images of the normal six-banded armadillo is lacking. Therefore, the present study was conducted to shed light on the anatomical details of the six-banded armadillo's nasal cavity using anatomical cross-sectional images and their correlation with transverse CT images.…”

“…Afterwards, the anatomic sections that better matched the CT images to identify the significant structures of the six-banded armadillo's sinuses and nasal passages were selected. Additionally, anatomical texts and notable references describing these species were also used [4,[19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”