ACTUAL Exam Questions and CORRECT
Answers
The Oldest indirect conversion digital radiography system used to acquire a digital image. -
CORRECT ANSWER - CCD
CCD: xray photons interest with the ______ material, the signal is transmitted by lenses or
_______ to the CCD. - CORRECT ANSWER - Scintillation material; fiberoptics
CCD: The visible light is transferred to one or more small _____ that convert the light into
electrical signal. - CORRECT ANSWER - capacitors
CCD: This charge is stored in a sequential pattern and released line by line and sent to the
______. - CORRECT ANSWER - ADC
A CCD is made up of a _______ receptor and electronics embedded in a substrate material in a
silicon chip. - CORRECT ANSWER - photosensitive
CCD: incident light from scintillator strikes the detector and electron hole pairs are produced in
the ____. - CORRECT ANSWER - Silicon
CCD: The electrons are held by _____ forces in the array until the charge is read out to form the
image. - CORRECT ANSWER - electrostatic
CCD: The detector element (del) contains 3 electrodes that hold the electrons in a
_______________. - CORRECT ANSWER - electrical potential well
CCD: The dels are formed by voltage gates that open and close during the readout to allow the
flow of _____. - CORRECT ANSWER - electrons
, CCD: To collect the charge of the silicon chips, the voltage sign is changed on the electrodes
with each del, moving the electrons by rows down the columns until the readout row is reached.
WHAT IS THIS CALLED? - CORRECT ANSWER - Bucket Brigade Scheme
CCD: when the readout row is reached, data is sent to the sense amplifier and are _____. -
CORRECT ANSWER - digitized
CCD: overfill of the dels is called? This is where excess electrons spill out into the adjacent del. -
CORRECT ANSWER - blooming effect
it is not practical to manufacture a CCD chip larger than - CORRECT ANSWER - 5cm x
5cm
CCD: Reducing the image size involves several components that contribute to the quality of the
image. (3 things) - CORRECT ANSWER - scintillator, light collection component, noise
CCD: the scintillator and the way it is contracted will determine: 3 - CORRECT
ANSWER - how many incident photons are absorbed, how much light is produced, color
of the light
The two main types of phosphors are ____ and _____. - CORRECT ANSWER - structured
and unstructured (turbid)
CsI is considered ____ bc of its needle-like projections. - CORRECT ANSWER -
structured
Gd202S is considered ____ bc of its powder-like granules. - CORRECT ANSWER -
unstructured
What focuses light onto the CCD chip? - CORRECT ANSWER - lenses or fiberoptics