CT Terms
Algorithm - answer a mathematical process applied to raw data for the purposes of
reconstruction, filtering, or enhancement of an image
Anode - answer the electrode at the end of an x-ray tube that, when struck by an
electron beam, produces x-ray photons
Aperture - answer the donut-shaped opening in the gantry through which the patient
and the patient table will pass during the scan
Array processor - answer a device that reconstructs images from raw data at a very
high rate of speed
Artifact - answer an appearance on a radiographic image that is unrelated to the
anatomical subject; includes aliasing, beam hardening, edge-gradient effects, and
effects caused by metal and motion
Hounsfield units (HU) - answerthe information contained in a single pixel assigned a
value correlating to a shade of gray; also called CT units
image matrix - answerthe electronic plane of pixels that combine to form the image
displayed on a monitor
noise - answerspots or blotches appearing on low-contrast images
pixel - answera two-dimensional picture element that represents the smallest discrete
block in a digital image display field; from picture element
scan field of view (SFOV) - answera reconstruction factor that refers to the area of
interest the scan field size is set to cover
slip ring - answera large metal ring inside the gantry that rotates the scanning
components and relays signals to and from the computer to perform the scan
spiral/helical CT scanning - answera scanning method in which certain x-ray tubes
rotate continuously around a patient until the entire area of interest has been scanned;
also called volume data acquisition
voxel - answera three-dimensional volume of tissue that corresponds to an individual
pixel on a CT image; from "volume element"
Algorithm - answer a mathematical process applied to raw data for the purposes of
reconstruction, filtering, or enhancement of an image
Anode - answer the electrode at the end of an x-ray tube that, when struck by an
electron beam, produces x-ray photons
Aperture - answer the donut-shaped opening in the gantry through which the patient
and the patient table will pass during the scan
Array processor - answer a device that reconstructs images from raw data at a very
high rate of speed
Artifact - answer an appearance on a radiographic image that is unrelated to the
anatomical subject; includes aliasing, beam hardening, edge-gradient effects, and
effects caused by metal and motion
Hounsfield units (HU) - answerthe information contained in a single pixel assigned a
value correlating to a shade of gray; also called CT units
image matrix - answerthe electronic plane of pixels that combine to form the image
displayed on a monitor
noise - answerspots or blotches appearing on low-contrast images
pixel - answera two-dimensional picture element that represents the smallest discrete
block in a digital image display field; from picture element
scan field of view (SFOV) - answera reconstruction factor that refers to the area of
interest the scan field size is set to cover
slip ring - answera large metal ring inside the gantry that rotates the scanning
components and relays signals to and from the computer to perform the scan
spiral/helical CT scanning - answera scanning method in which certain x-ray tubes
rotate continuously around a patient until the entire area of interest has been scanned;
also called volume data acquisition
voxel - answera three-dimensional volume of tissue that corresponds to an individual
pixel on a CT image; from "volume element"
