Evaluation of sectional anatomic, micro-computed tomographic, and magnetic resonance imaging features of the thorax in Syrian hamsters (Mesocricetus auratus)

Abstract

Clinically, the rodent thorax is important because of the variety of problems that may affect the heart, lungs, and other thoracic structures. Syrian hamsters are the most common pet and experimental hamster species. Sectional imaging of small mammals is widely increasing in use for clinical and research settings; however, no reports on the thoracic sectional imaging anatomy in this species have been made. Therefore, this study aimed at evaluating micro-computed tomography (MCT), magnetic resonance image (MRI), and gross sections of the Syrian hamster thorax. Eight healthy adult male and female Syrian hamsters were examined. Anesthetized hamsters were evaluated by MCT and 3 Tesla MRI. After imaging, the frozen slab sections were photographed, and identified anatomic structures were matched with structures on corresponding MCT and/or MRI images. Clinically relevant anatomic features of the Syrian hamster thorax that were identified on transverse and sagittal anatomic sections could be discerned on the corresponding MCT and MRI scans. The three matched images were exhibited the following features: (1) the narrow thoracic cavity and small lung space, (2) the heart positioning ventral and medial to lung, (3) heart ventricles locating towards the left side, and (4) parallel cardiac position relative to the sternum. The obtained results were similar to those have only been reported in rabbits, regardless of heart orientation and lung lobe covering the heart. The results of this study support the use of MCT and MRI as diagnostic tools in Syrian hamsters and provide reference values for the clinically relevant anatomic structures of thorax.

Keywords: Cross-sectional imaging; Macroscopic anatomy; Planar anatomy; Rodent; Small exotic companion mammals; Thoracic cavity.