Chapter 12 Image Acquisition & Technical Factors Flashcards
What does contrast resolution measure?
The ability to distinguish differences in tissue densities.
What is the difference between radiolucent and radiopaque structures?
Radiolucent = X-rays pass through (dark on image). Radiopaque = X-rays absorbed (bright on image).
What does pixel size affect in digital imaging?
Spatial resolution (smaller pixels = better resolution).
What is spatial contrast?
The ability to distinguish fine details based on spatial differences.
What does photo-stimulated luminescence (PSL) refer to?
The emission of light from a phosphor when exposed to a laser in CR imaging.
What does OSL (Optically Stimulated Luminescence) dosimetry measure?
Radiation exposure, using light stimulation rather than heat.
What is the main purpose of postprocessing in digital radiography?
To enhance image quality (adjust brightness, contrast, and sharpness).
How does spatial frequency affect image sharpness?
Higher spatial frequency = Better sharpness.
What is dose creep, and why is it a concern?
Increasing exposure over time for better image quality, leading to unnecessary radiation dose.
What happens to image contrast when kVp is increased?
Contrast decreases (longer gray scale).
What does scintillation describe?
A flash of light emitted by a material when struck by radiation.
What is the relationship between mAs and x-ray quantity?
Directly proportional (higher mAs = more x-rays).
What is the effect of higher atomic number materials on x-ray interactions?
More photoelectric absorption, increasing contrast.
What is window leveling used for in digital radiography?
Adjusting image brightness.
What is window width used for?
Adjusting contrast in the digital image.
What is contrast resolution determined by?
The bit depth of the imaging system.
What type of radiation interaction does mammography primarily rely on?
Photoelectric effect, for high-contrast breast imaging.
What is the purpose of grids in x-ray imaging?
To reduce scatter radiation, improving image contrast.
Why is fluoroscopy different from conventional x-ray?
It provides real-time, dynamic imaging.
What is spatial resolution measured in?
Line pairs per millimeter (lp/mm).
