A computed axial tomography scan or CAT Scan is a medical imaging technology that uses finely focused X-rays together with a detector rather than photographic film combined with computer imaging technology to create detailed three-dimensional images of interior body tissue, including soft tissue. It is primarily used to detect and locate structures within the body that cannot be located by other forms of radiological investigation.
Dr. Janet Fraiser preformed a CAT Scan on Rya'c when he traveled to Stargate Command. (SG1: "Family")