Digital Imaging Flashcards

Flashcards for Digital Imaging

Digital Imaging

Image is produced, processed, viewed, and stored on a computer.

Computed Radiography (CR)

Digital imaging system using cassettes containing photostimulable phosphor plates, and requires a CR reader for image processing.

Digital Radiography (DR)

Digital imaging system referred to as 'cassette-less' because the flat-panel detector is incorporated into the x-ray table or upright wall unit.

Pixel

An element in a digital image.

Spatial resolution

The smallest detail that can be detected in an image.

Contrast resolution

The ability to distinguish between different densities in the image.

Dynamic range

The range of exposures that can be captured by a detector.

Signal-to-noise ratio (SNR)

Ratio of useful signal to unwanted noise.

Fill factor

The percentage of the pixel area that is sensitive to x-ray exposure.

Histogram

A graphical representation of the pixel values in an image.

Sample frequency

The rate at which data is sampled.

Electronic medical record

A digital collection of patient medical information.

Look up table

A control system that can change the brightness and contrast of the image.

Modulation transfer function

A measure of the imaging system’s ability to display contrast of anatomical objects varying in size.

Cropping/masking

The process of removing unwanted areas from the digital image.

Analog-to-digital converter (ADC)

Converts analog signal into digital data.

Dead pixels

Non-functioning pixels in the detector.

Smoothing

A post-processing technique to reduce noise (or graininess) in a digital image.

Rescaling

The process of adjusting the image data to optimize display.

Picture Archival and Communication System (PACS)

Used to manage images; consists of computers, servers, and archives.

Common Artifacts

Quantum mottle, Moire pattern, Light spots, Phantom/ghost images, Scratches or tears.

DICOM

A standard for handling, storing, printing, and transmitting information in medical imaging.