Electronic noise decreases the image quality. There are various noise sources in any electronic system, including Johnson noise, shot noise, or thermal noise. Electronic noise can be caused by vibrations of any of the hardware components, especially the rotational components of a CT scanner or power fluctuations.

(EDP) The term electronic data processing describes the automated processing of commercial data by computer systems.

See also Boot Terminal, Anticoincidence, Electronic Noise, Impedance Matching, Demodulator, and Hard Disk.

Radiographic noise is a fluctuation in optical density on radiographic or mammographic images, often as a result of low radiation dose.

See also Electronic Noise.

Image quality is an important value of all radiographic imaging procedures. Accurate measures of both image quality and patient radiation risk are needed for effective optimization of diagnostic imaging. Images are acquired for specific purposes, and the result depends on how well this task is performed. The imaging performance is mainly influenced by the imaging procedure, examined object, contrast agents, imaging system, electronic data processing, display, maintenance and the operator. Spatial resolution (sharpness), contrast resolution and sensitivity, artifacts and noise are indicators of image quality.
A high image contrast provides the discrimination between tissues of different densities.
The image resolution states the distinct visibility of linear structures, masses and calcifications.
Noise and artifacts degrade the image quality. In computed tomography (CT), high spatial resolution improves the visibility of small details, but results in increased noise. Increased noise reduces the low contrast detectability. Noise can be reduced by the use of large voxels, increased radiation dose, or an additional smoothing filter, but this type of filter increases blurring.
An image acquisition technique taking these facts into account maximizes the received information content and minimizes the radiation risk or keeps it at a low level.

See also As Low As Reasonably Achievable.