Computed Tomography and Magnetic Resonance Anatomy of the Normal Orbit and Eye of the Horse.

The research focuses on using computed tomography (CT) and magnetic resonance imaging (MRI) to analyze the eye and orbit of a horse to enhance the diagnosis and treatment of traumatic and infectious eye diseases. The study presents anatomical details and relationships of the structures in the equine orbit and eye via CT and MRI.

Methodology

• The researchers used the heads of four adult horses, scanning them with a 6-slice Emotion 6 CT and a 3.0 Tesla Siemens Verio 6 MRI.
• Both CT and MRI scans were performed using T1 and T2-weighted sequences.
• The CT and MRI reference images generated were compared with anatomical models and gross anatomical sections to ensure accuracy.

Findings

• The CT scans effectively identified the bony limits of the orbital cavity and the relationship of the orbit with sinuses and foramina of the skull.
• MRI scans were useful in observing soft tissues within the orbit and the eye, and more significantly, in identifying the adnexae of the ocular globe which include the eyelids, periorbital fat, extraocular muscles, lacrymal and tarsal glands.
• MRI scans were able to identify all components of the eye, including the posterior chamber. However, MRI was not able to differentiate sclera (the white of the eye) from the choroid and retina (the back of the eye).
• The optic nerve was the only nerve identified through these scans.
• Vascular structures were not identified in the cadaver heads used in the study.

Conclusions

• The study concluded that both CT and MRI scans are useful techniques to image the equine orbit and eye, contributing to better anatomical understanding and clinical diagnosis.
• While both methodologies provide useful anatomical data, they each offer unique insights, with CT scans being better suited for bone structure and MRI being more precise for soft tissue differentiation.