Introduction

Exotic animals are being imaged more and more regularly via computed tomography as well. However, due to their size and different anatomy standard small animals - or even human - CT protocols, including normal range of Hounsfield units (HU), cannot just be transferred. Common presenting diseases in the common marmoset include renal, liver, and skeletal disease. Normal abdominal ultrasonographic and radiographic anatomy as well as the thoracic anatomy via computed tomography (CT) in the common marmoset has been described.

Objectives

The aim of this study was to investigate the feasibility of abdominal computed tomography in the clinically normal common marmoset and to determine the normal reference range of Hounsfield units (HU) of major abdominal organs.

Materials

Eight unrelated, clinically healthy, mature male (n=5) and non-pregnant female (n=3) marmosets (ranging from 12 to 48 months) were included in this CT study. They were anesthetized, and pre- and post-contrast CT examinations were performed using different CT settings.

Results

The HU of major abdominal organs differed from small animals. Information gained from survey CT was often limited. Identification or delineation of abdominal organs greatly improved with IV contrast. Modification of the window settings of the post-contrast images is recommended. Additionally, a modified high-frequency algorithm with edge enhancement added valuable information for interpretation and identification of small structures, such as the ureters.

Conclusions

In conclusion, due to their size and different anatomy, standard small animal CT protocols need to be critically assessed and adapted for the common marmoset.