Computed tomography (CT) uses ionizing radiation to create an image. This allows visualization of a greater variety of tissue structures beyond the four basic densities (air, bone, soft tissue, and fat) that are seen on a conventional radiograph. Unlike conventional x-rays, which utilize one projection to form an image, CT uses multiple small projections across the body and combines the information to form the image. It is this combining of the images that allows greater soft tissue detail to be displayed.
- Hounsfield Unit
- Gray scale