Radiographic Image Analysis -Chapter 1- Key
Terms
ALARA -
As Low As Reasonably Achievable
Annotation -
Adding markers (R or L text words) to the radiograph after the exposure has been made
from the computer display monitor.
Anterior -
Refers to the front surface of the patient, used to express something situated at or directed
toward the front: includes the palm and tops of the feet as in anatomic position ( sternum is anterior to
the vertebral column)
Atomic Density -
the concentration of atoms within a given tissue space
Background Timer -
Maximum time that the AEC x-ray exposure will be allowed to continue before
automatically shutting off.
Contrast Mask -
a post-processing manipulation that adds a black background over the areas outside the
VOI to eliminate them and provide a perceived enhancement of image contrast
Decubitus -
Refers to the patient lying down on a table or cart while a horizontally directed CR is used;
also used the term decubitus is the surface (lateral, dorsal, or ventral) placed adjacent to the table or
cart, The patient is in a left lateral decubitus position.
(DEL) detector element- -
Element in the DR image receptor that contains the electronic components that store the
detected energy
Distortion -
The misrepresentation of the size or shape of structure being examined.
Dose Creep -
When technique values (mAs, kV) are elevated more than necessary because of fear of
producing images with quantum noise.
Dose equivalent limit -
maximum permissible radiation dose limits; used for radiation protection purposes
