Mouse CT scans. Coloured three-dimensional (3-D) computed tomography (CT) scans of an obese laboratory mouse (Mus musculus). The skeleton (orange) of this mutant mouse (blue) is at lower frame. This image is from MicroCAT, a CT scanner developed to study small animals like mice by creating images with 10 times the resolution of conventional scanners. The mouse's development can be monitored; mice such as this are bred for genetic analysis. Here the CT scans, slice images through the body made using X-rays, have been built into 3-D images with a computer. The scanner was developed at the Department of Energy's Oak Ridge National Laboratory, USA.