Image Production & Processing Flashcards

Which term describes the process of adjusting image brightness and contrast after acquisition in digital radiography?

Answer: Postprocessing (image manipulation)

Postprocessing allows digital manipulation of window width and window level after the image is acquired, adjusting contrast and brightness.

What does window width (WW) control in digital image display?

Answer: Image contrast (the range of gray shades displayed)

Window width determines the range of Hounsfield units (or signal values) mapped to the gray scale, controlling the number of gray shades and thus image contrast.

In computed radiography, what material is used in the imaging plate to store the latent image?

Answer: Photostimulable phosphor (PSP)

CR imaging plates use photostimulable phosphor (typically europium-doped barium fluorohalide) to trap energy from x-rays as a latent image.

What is the effect of increasing SID on radiographic magnification?

Answer: Magnification decreases

Increasing SID reduces magnification because the object is a smaller proportion of the total source-to-image distance.

Which grid ratio produces the greatest cleanup of scatter radiation?

Answer: 16:1

A 16:1 grid ratio provides the most efficient scatter cleanup because the tall, closely spaced grid strips preferentially absorb angled scatter photons.

What is the primary purpose of the anti-scatter grid in radiography?

Answer: To improve image contrast by absorbing scatter radiation before it reaches the detector

Anti-scatter grids absorb scattered photons that would otherwise reach the detector and reduce image contrast.