A dedicated small animal x-ray computed tomography system has been developed to screen mutagenized mice for anatomical phenotypes. The key components of the data acquisition instrumentation are described along with the system performance parameters. Image reconstruction, visualization and segmentation software algorithms are described. Two contrast media regimens are described and representative studies of mice with adipose, soft and skeletal tissue abnormalities are presented.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.