The growing role of CT imaging in evaluating head problems in horses is discussed in a recently published review.
Susanne Stieger-Vanegas and Ashley Hanna, writing in the Frontiers in Veterinary Science journal, noted that diseases affecting the head of horses occur frequently.
Head radiographs provide good spatial resolution in equine patients, they said, but identifying lesions in these x-rays can be challenging. Subtle lesions can even go undetected.
“In cases where clinical examination, radiography and endoscopy do not provide enough information, or when there is incomplete or no response to treatment, additional diagnostic imaging methods are often considered.
“The equine head is an anatomically and spatially very complex structure, and cross-sectional imaging techniques such as computed tomography (CT) or magnetic resonance tomography (MRI) are useful to eliminate superimposition of anatomic structures.”
While MRI is usually preferred for evaluating the brain and spinal cord, CT is often the method of choice for evaluating bones or air-filled structures.
CT imaging of the head in horse patients is now common as scanners are more readily available, they noted.
It is, they said, an excellent technique to evaluate the head and can provide good anatomical understanding of a broad range of lesions.
“Head CT has been demonstrated to be incredibly valuable in the evaluation of dental and paranasal sinus disease, disease of the hyoid apparatus and ear, and in evaluation of skull trauma.”
It is excellent for assessing bone and soft tissue structures. However, evaluation of complex vascular anatomy and determination of tissue viability is limited without the use of contrast agents. Therefore, various contrast agent protocols have been established.
“Head CT images are most commonly evaluated in transverse planes. However, standard multiplanar reconstructions of the head including dorsal and parasagittal planes improve the understanding of spatially complex disease processes.”
These reconstructions can be crucial for accurate identification of diseased teeth and determination of the extent and severity of osseous [bone] and paranasal sinus disease.
Head CT examinations are becoming an increasingly important diagnostic tool for head disorders, they said, with the findings becoming an important part of the clinical decision-making process.
“In addition, it has great value in the planning of interventional procedures and the removal of masses occurring on the head,” the pair wrote.
CT may eliminate the need for other diagnostic imaging studies, especially when the CT can be performed in standing horses.
“The ability to perform thin slices and multiplanar reconstructions of the head can help to more accurately evaluate head pathologies, especially in patients with trauma to the head, ear disease, or dental abnormalities.”
Stieger-Vanegas is with the Department of Clinical Sciences at the Carlson College of Veterinary Medicine at Oregon State University. Ashley Hanna is with the College of Veterinary Medicine at Washington State University.
Stieger-Vanegas SM and Hanna AL (2022) The Role of Computed Tomography in Imaging Non-neurologic Disorders of the Head in Equine Patients. Front. Vet. Sci. 9:798216. doi: 10.3389/fvets.2022.798216