Cory's Shearwater (Calonectris borealis): Exploring Normal Head Anatomy through Cross-Sectional Anatomy, Computed Tomography and Magnetic Resonance Imaging

Cory's shearwater, or Calonectris borealis, stands out as a symbolic figure in the world of seabirds, playing a crucial role in marine ecosystems globally. Belonging to the Procellariidae family, it is singularized by its imposing wingspan and intricate migration patterns connecting it to various regions from the North Atlantic to the Pacific. Its role in the marine food chain, specialized diet and adaptation for nesting in the Canary Archipelago underscore its ecological importance. However, Cory's shearwater also faces important threats, such as the invasion of foreign species, highlighting the need for its conservation. Among the conservation issues, studies on its biology, the main threats it faces and its normal anatomy are essential to preserve marine biodiversity. Additionally, a variety of imaging techniques, such as computed tomography and magnetic resonance, facilitates the understanding of the bird's neuroanatomy and opens future research possibilities in comparative neuroscience. Moreover, this approach proves particularly relevant given the increasing attention these seabirds receive in environments such as zoos, rehabilitation centers and their natural habitat, where veterinarians play a crucial role in their care and well-being.

Cross Sectional Anatomy and Magnetic Resonance Imaging of the Juvenile Atlantic Puffin Head (Aves, Alcidae, Fratercula arctica)

The Atlantic puffin is a medium-sized seabird with black and white plumage and orange feet. It is distributed mainly along the northern Atlantic Ocean, and due, among other reasons, to human activities, it is in a threatened situation and classified as a vulnerable species according to the International Union of Conservation of Nature (IUCN). In this study, we used a total of 20 carcasses of juvenile Atlantic puffins to perform MRI, as well as anatomical cross-sections. Thus, an adequate description of the head was made, providing valuable information that could be helpful as a diagnostic tool for veterinary clinicians, who increasingly treat these birds in zoos, rehabilitation centers, and even in the wild.

Cross-Sectional Anatomy and Computed Tomography of the Coelomic Cavity in Juvenile Atlantic Puffins (Aves, Alcidae, Fratercula arctica)

In birds, unlike mammals, there is no complete separation between the thoracic and abdominal cavities. Instead, they have the coelomic cavity where most main organs are found. Therefore, an adequate knowledge of the anatomy of the coelomic cavity is of great importance for veterinarians, biologists and the scientific community. This study aimed to evaluate the coelomic cavity anatomy in the Atlantic puffin (Fratercula arctica) using anatomical sections and computed tomography images.

Endoscope and image-guided ventral bulla osteotomy in the dog: A cadaveric and patient study

BACKGROUND

Surgery of the bulla in the dog can be difficult and associated with suboptimal resolution of disease and risk of complications, particularly in treatment of cholesteatoma. We explored use of image guidance and endoscopic assistance in ventral bulla osteotomy (VBO), initially with cadaveric studies and subsequently on dogs with cholesteatoma.

METHODS

For surgical approach we used cone beam CT with an optical image navigation system. For endoscopic surgery we used 4 mm and 2.7 mm diameter endoscopes and a camera viewing system, with micro-instruments for dissection.

RESULTS

Image guidance allowed us to accurately identify and approach the bulla in cadavers (n = 2) and patients (n = 2). The endoscope enabled us to define detailed endoscopic anatomy in cadaveric canine heads (n = 15), and in patients (n = 5) it enabled reliable and safe removal of pathological tissue.

CONCLUSION

Image and endoscopic assistance could be a significant advance to the reliability and safety of VBO. Our techniques may be applicable to other indications and species.

Computed tomographic and gross anatomy of the head of the blue-fronted Amazon parrot (Amazona aestiva)

The blue-fronted Amazon parrot is an extremely popular pet bird in Brazil. These birds are commonly raised in captivity and are often seen in veterinary practice. Modern imaging modalities such as computed tomography (CT), which had not been widely used in wild and exotic bird medicine until recently, are now becoming more popular due to wider availability and higher diagnostic accuracy. However, proper interpretation of tomographic findings requires species-specific anatomical references. Studies investigating normal tomographic anatomy of parrots are scarce. This study set out to describe the normal anatomy of the head of the blue-fronted amazon parrot (Amazona aestiva) using conventional CT. Anatomical descriptions may contribute to future comparative morphology studies and assist in clinical practice. The head of the blue-fronted Amazon parrot is structurally similar to other bird species. Major differences detected were are as follows: size and position of nasal conchae (long middle concha and small caudal concha located at the end of the nasal cavity), infraorbital sinus aperture located on the lateral aspect of the nasal cavity, presence of a nasopharyngeal duct connecting the nasal and oral cavities, longer infraorbital sinus with a larger number of caudal compartments and paraglossum with morphological features unique to psittacines. High-quality CT images were vital for identification and detailed description of most head structures. Multiplanar reconstruction was a useful tool for complete visualization of the head. However, conventional CT images were not good enough for visualization of the inner ear and related structures, as well the paratympanic sinus.

3.0 Tesla magnetic resonance imaging anatomy of the central nervous system, eye, and inner ear in birds of prey

Despite the increasing interest in the clinical neurology of birds, little is known about the magnetic resonance imaging (MRI) appearance of the avian central nervous system, eye, and inner ear. The objective of this cadaveric study was to document the MRI anatomic features of the aforementioned structures using a high-resolution 3.0 Tesla MRI system. The final study group consisted of 13 cadavers of the diurnal birds of prey belonging to six species. Images were acquired in sagittal, dorsal, and transverse planes using T1-weighted and T2-weighted turbo spin echo sequences. A necropsy with macroscopic analysis of the brain and spinal cord was performed on all cadavers. Microscopic examination of the brain was performed on one cadaver of each species; the spinal cord was examined in three subjects. Anatomic structures were identified on the magnetic resonance images based on histologic slices and available literature. Very good resolution of anatomic detail was obtained. The olfactory bulbs; cerebral hemispheres; diencephalon; optic lobe; cerebellum; pons; ventricular system; optic, trigeminal, and facial nerves; pineal and pituitary glands; as well as the semicircular canals of the inner ear were identified. Exquisite detail was achieved on the ocular structures. In the spinal cord, the gray and white matter differentiation and the glycogen body were identified. This study establishes normal MRI anatomy of the central nervous system, eye, and inner ear of the birds of prey; and may be used as a reference in the assessment of neurologic disorders or visual impairment in this group of birds.