Digital Imaging Characteristics

Vocabulary flashcards covering key terms and definitions from the lecture on Digital Imaging Characteristics, including concepts related to pixels, matrices, exposure indicators, image quality metrics, and detector performance.

Analog Image

An image created from a continuously varying signal, such as a watch with hands that move smoothly.

Digital Image

An image recorded as discrete numeric values divided into an array of small elements that can be processed in multiple ways.

Pixel

The smallest element in a digital image

Bit Depth

Number of shades of gray in the digital system being displayed

Matrix

A square arrangement of numbers in rows and columns in which each box corresponds to a pixel’s location and value.

Spatial Resolution

The ability of an imaging system to display small details; improves with smaller pixel size.

Contrast Resolution

A system’s ability to display subtle differences in gray shades; directly related to pixel bit depth.

Dynamic Range

The range of exposure values a detector can respond to; larger ranges record more information but do not guarantee higher spatial resolution.

Air Kerma (Gy)

Kinetic energy release per unit mass of air is the measurement of radiation energy absorbed in a unit of air

Standardized Radiation Exposure (KSTD)

The standardized radiation exposure is a standard exposure typical of the imaging receptor system

Indicated Equivalent Air Kerma (KIND)

Indicated equivalent air karma is the measurement of radiation that was incident on the image receptor for the particular exposure

Target Equivalent Air Kerma (KTGT)

Is a subtle values that have been established by either the system manufacturer or by the system usually that represents an optional exposure for each specific body part and view

Deviation Index (DI)

Logarithmic difference between actual exposure (KIND) and target exposure (KTGT); 0 = ideal, negative = underexposed, positive = overexposed.