Digital Imaging and Radiographic Physics Flashcards

A collection of vocabulary flashcards covering key terms in digital imaging, radiation exposure, and radiographic image quality based on lecture notes from $$6/03/26$$ and $$6/10/26$$.

Noise

Photon dependent, visible brightness fluctuations and graininess in a xray image, where fewer photons lead to greater noise and negatively affect visibility related to exposure.

Signal to noise ratio (SNR)

The strength of radiation exposure compared with the amount of noise in an image.

Exposure latitude

The range of exposure values to the image, representing the acceptable range of densities for diagnostic purposes.

Detective quantum efficiency

A measurement of the efficiency of the IR in converting the x-ray exposure it receives to quality xrays.

Brightness

The amount of luminance on a display monitor.

Magnification

The increase in image size of the object compared with its true or actual size, also known as distortion.

Shape distortion

Images that appear longer or shorter than the true objects.

Sharpness

The accuracy of structural lines and well defined edges on a final image.

Histogram

A graphic display of pixel values where the computer analyzes the shape to build the final visible image.

Nyquist theorem

The speed limit for digital sampling, stating that one must scan/sample $2$ times as fast as its high frequency.

Aliasing

A digital pattern glitch, also referred to as a moire pattern.

Look up table (LUT)

A pre-calculated math function or digital structure used during post processing to map pixel values to new output pixel values.

Edge Enhancement

A postprocessing technique that improves the visibility of small, high contrast structures.

High Pass filtering

An edge boosting trick where a computer math filter blocks specific frequencies.

Digital Imaging

A computer communication standard language for information sharing, picture archiving, and communication systems (PACS) that allows for instant viewing, easy archiving, and manipulation.

Tele-radiology

An electronic system that allows patient electronic records and images offsite or within a facility, enabling radiologists to provide remote interpretation and diagnosis.