Radiologic Anatomy of the Thorax of the Southern Giant Pouched Rat (Cricetomys ansorgei)

Abstract

The southern giant pouched rat (Cricetomys ansorgei) is a large rodent native to the savannahs of southern and East Africa, commonly kept as a pet and used for medical purposes, including the detection of pulmonary tuberculosis, Brucella infection, and land mines. Despite its biomedical significance, limited information exists on its thoracic radiological anatomy. This study aimed to describe the normal thoracic radiographic anatomy of Cricetomys ansorgei to support anatomical and clinical research. Radiographs of 34 adult southern giant pouched rats were taken under general anaesthesia, including right lateral (RL) and dorsoventral (DV) views of the thorax. Most rats exhibited 13 thoracic vertebrae and 13 pairs of ribs, with the last two floating pairs. All rats displayed six sternebrae, and the trachea was visible without mineralised cartilaginous rings. The cranial mediastinum appeared wider than the spine in all individuals. The cranial border of the cardiac silhouette was poorly visualised on the RL view but more clearly defined and oblong-shaped on the DV view. The mean vertebral heart size (VHS) measured on the DV view (10.59) was significantly larger than that measured on the RL view (9.49). Additionally, gravel and sand grains were commonly observed in the cranial abdomen. While the thoracic anatomy of Cricetomys ansorgei shares some characteristics with other rodents, rabbits, and domestic cats, several distinctive anatomical features were identified. These findings provide a valuable reference for anatomical studies, biomedical applications, and routine clinical assessments.