Using Computed Tomography Scanning for Diagnosing Masticatory Muscle Pathologies in Dogs

Introduction. The problem of diagnosing the masticatory muscle pathologies in dogs remains relevant both for  veterinary science and practice, as masticatory muscle diseases can lead to the loss of appetite and, as a result, to deterioration of animal overall health. Modern imaging techniques, such as computed tomography (CT) scanning, are still rarely used in veterinary medicine for diagnosing the pathologies. The aim of the present study is to perform CT scanning of the masticatory muscles in dogs and evaluate the diagnostic capacities of this technique by comparing the CT scans of these muscles to macroscopic anatomy sections thereof.

Materials and Methods. The study was conducted at the premises of VitaVet Veterinary Clinic and in the anatomical theatre of Don State Technical University from November 2023 to March 2024. The objects of the study were dogs (n=3). Three-phase CT scans were taken: arterial, venous, and delayed. After CT scanning and euthanasia, the animal cadavers were frozen at the temperature of –20°C for one week. The muscle sections for macroscopic anatomy analysis were obtained using a circular saw table. Alinement of CT images with the actual anatomical structure was established by comparing the macroscopic anatomy sections against the axial and sagittal CT projections of these structures.

Results. The anatomical site and topographic relationships of the masticatory muscles with the associated tissues in canine cadavers were described using computed tomography scanning and macroscopic anatomy analysis of muscle sections. By comparing CT images to the macroscopic anatomy sections, a high degree of matching between them was revealed: the masseter muscle and temporalis muscle silhouettes on CT scans completely matched with their topography in frozen sections. Minor differences in tissue thickness and density were observed in the pterygoid muscles, which could be explained by the features of soft tissue cutting and shrinkage during freezing.

Discussion and Conclusion. Computed tomography scanning is a preferred imaging technique for the masticatory muscles in the head of an animal, as it enables precise determination of the location, quantity, size, and intensity of morphological changes in the muscles reflecting their condition and degree of involvement in the pathological process. However, several constraints should be borne in mind when considering the obtained results: the study was conducted in a small number of animals; the pathologies were not clinically confirmed in the cadavers used for the study, etc. The prospects of future research lie in expansion of the size of a sample to include the animals of different breeds and ages, as well as in incorporation of the clinical cases of myositis, tumours and post-traumatic changes in the masticatory muscles. This will improve the accuracy of diagnostics and efficacy of therapy.

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