A slice is a tomographic section of an object. A slice is defined by position and thickness; each slice is divided into a matrix of voxels. In computed tomography, a motorized table slips the patient through the gantry and slices are made when the x-ray tube rotates in a circle around the patient.

Zooming increases scale factors of images within a window. Zooming takes a selected region and extends it over the entire matrix of the displayed CT image. Usually, a zoom reconstruction increases the accuracy of the CT numbers by decreasing the overall size of the displayed image pixels, which decreases the possibility of many tissues occupying a single pixel (partial volume averaging).
Zooming or targeting is not the same as image magnification.

See also Banding.