"CT (computed tomography), sometimes called a CAT scan, uses a combination of X-rays and computer technology to produce two-dimensional cross-sectional images (slices) both horizontally and vertically, of the body.

Unlike conventional X-rays, which take a single picture of a part of the body, computed tomography generates multiple X-ray images in a single examination. Despite the large number of images, the total amount of radiation can be less from a CT scan than from some conventional X-ray procedures.

While much information can be obtained from a regular X-ray, a lot of detail about internal organs and other structures is not available. In a CT scan, the X-ray beam moves in a circle around your body. This allows many different views of the same organ or structure and provides much greater detail. The X-ray information is sent to a computer that displays it in two-dimensional form on a computer. While CT scans show the inside of the body in much greater detail than a conventional X-ray, high-resolution CT is available at CHI Franciscan Health when there is a need to see an area in extremely small detail.

CT scans may be done with or without contrast. This “contrast” refers to a substance taken by mouth or injected into an intravenous (IV) line that causes the particular organ or tissue to stand out more clearly."

https://www.chifranciscan.org/health-care-services/diagnostic-imaging-radiology-services/tests-and-procedures/ct-scan.html