Ch. 15 Bushong Challenge Questions
Define imaging plate - answerA photostimulable phosphor bound in a cassette as an
image receptor is an imaging plate.
Define activator - answer Europium (Eu) is the activator in a photostimulable phosphor.
It is the latent image center in computed radiography.
Define signal sampling - answerThe time varying analog signal from the photo detector
is processed and digitized with attention paid to proper sampling time (time between
samples) and quantization (the value of each sample).
Define metastable electron - answerAn electron in an excited energy state beyond its
normal orbital energy state.
Define polychromatic - answerA broad spectrum of wavelengths (colors) of visible light.
Define fast scan - answerThe rapid manner in which the laser beam is swept across the
imaging plate by oscillating mirrors and lenses.
Define prompt emission - answerElectrons raised to an excited state by x-ray exposure
return to the ground state with an immediate emission of light. There is no latent image
with these electrons.
Define storage phosphor - answerA phosphor such as barium fluorohalide, where
electrons in a metastable state are not released to the ground state until stimulated with
light. The latent image is stored in the phosphor.
Define turbid - answerThe white appearance of phosphor particles because of their
small size.
Define photodiode - answerPhotodiode is a silicon solid state device sensitive to light. It
converts light into an electrical signal.
What workload steps are omitted when one is converting from screen-film radiography
to computed radiography? - answerThe necessary reloading of the cassette.
Identify three photostimulable phosphors. - answerBaFBr:Eu, BaFI:Eu, and BaFF:Eu.
How is the latent image formed in computed radiography? - answerElectrons are
energized by x-ray interaction into excited metastable energy states. They remain in
these excited states until released by exposure to laser light.
Define imaging plate - answerA photostimulable phosphor bound in a cassette as an
image receptor is an imaging plate.
Define activator - answer Europium (Eu) is the activator in a photostimulable phosphor.
It is the latent image center in computed radiography.
Define signal sampling - answerThe time varying analog signal from the photo detector
is processed and digitized with attention paid to proper sampling time (time between
samples) and quantization (the value of each sample).
Define metastable electron - answerAn electron in an excited energy state beyond its
normal orbital energy state.
Define polychromatic - answerA broad spectrum of wavelengths (colors) of visible light.
Define fast scan - answerThe rapid manner in which the laser beam is swept across the
imaging plate by oscillating mirrors and lenses.
Define prompt emission - answerElectrons raised to an excited state by x-ray exposure
return to the ground state with an immediate emission of light. There is no latent image
with these electrons.
Define storage phosphor - answerA phosphor such as barium fluorohalide, where
electrons in a metastable state are not released to the ground state until stimulated with
light. The latent image is stored in the phosphor.
Define turbid - answerThe white appearance of phosphor particles because of their
small size.
Define photodiode - answerPhotodiode is a silicon solid state device sensitive to light. It
converts light into an electrical signal.
What workload steps are omitted when one is converting from screen-film radiography
to computed radiography? - answerThe necessary reloading of the cassette.
Identify three photostimulable phosphors. - answerBaFBr:Eu, BaFI:Eu, and BaFF:Eu.
How is the latent image formed in computed radiography? - answerElectrons are
energized by x-ray interaction into excited metastable energy states. They remain in
these excited states until released by exposure to laser light.
