Digital Radiography and PACS 4th
Edition EXAM QUESTIONS WITH
CORRECT ANSWERS||100%
GUARANTEED PASS||UPDATED
2025/2026 SYLLABUS||A+
GRADED||<<NEWEST VERSION>>
Image processor - ANSWER ✓ A device that processes the electrical signals from
the detector to create an image.
Noise cancelling - ANSWER ✓ The process of reducing unwanted signals in
image data.
Analog-to-digital conversion - ANSWER ✓ The process of converting analog
signals into digital format.
Readout - ANSWER ✓ The process of retrieving data from the imaging system.
Line scanning sequence - ANSWER ✓ The order in which the imaging system
scans the area to capture an image.
Amorphous silicon detector - ANSWER ✓ A type of detector used in digital
radiography.
CsI detector - ANSWER ✓ A detector that uses thin crystalline needles.
Light spread in CsI detectors - ANSWER ✓ There is very little light spread.
Gd2O2S scintillator - ANSWER ✓ Known as both 'Turbid' and 'Unstructured'
phosphor.
, Detector performance measurements - ANSWER ✓ Measured with spatial
resolution, observation of flow contrast objects in a phantom, and DQE.
Defective pixels - ANSWER ✓ Can result from chemical corrosion, static
discharge, and dust.
Standard for defective pixels - ANSWER ✓ Manufacturers aim for less than 0.1-
0.2% defective pixels.
Causes of image lag - ANSWER ✓ Include rapid succession images,
overexposure, and lack of beam attention.
Interpolation - ANSWER ✓ Uses information from surrounding pixels to 'fill in'
missing information.
Decreasing image lag - ANSWER ✓ Can be done by increasing the amount of
time between exposures.
Absorption material attachment - ANSWER ✓ Can be attached to the pixel array
electrically or physically.
2-D array in imaging - ANSWER ✓ Does not determine whether the imager is
direct conversion or indirect conversion.
Gain calibration - ANSWER ✓ Will remove inherent detector artifacts from an
image.
Offset correction - ANSWER ✓ Used to remove inherent signal that remains in a
detector.
Flat-panel detector systems - ANSWER ✓ Do not all have the ability to take
images faster than the detector can accommodate.
Direct image capture - ANSWER ✓ A method of capturing images directly
without intermediate steps.
Indirect image capture - ANSWER ✓ A method of capturing images that involves
intermediate steps.
,Spatial resolution - ANSWER ✓ A measurement of the ability to distinguish small
details in an image.
Observation of flow contrast objects - ANSWER ✓ A method to evaluate detector
performance.
DQE - ANSWER ✓ Detective Quantum Efficiency, a measure of detector
performance.
Chemical corrosion - ANSWER ✓ A potential cause of defective pixels in
detectors.
Static discharge - ANSWER ✓ Can lead to the occurrence of defective pixels.
Dust - ANSWER ✓ Can contribute to the presence of defective pixels.
Overexposure - ANSWER ✓ Can lead to image lag in radiographic imaging.
Underexposure - ANSWER ✓ Not a cause of image lag.
Charge-Coupled Device (CCD) - ANSWER ✓ It is the oldest indirect conversion
technology used in a variety of image capture applications.
Indirect conversion detector - ANSWER ✓ A device that acts like a camera in an
indirect conversion detector is known as a CCD.
Components that focus signals - ANSWER ✓ The components that focus the
signal from the scintillators to the CCD are called fiber optics.
Capacitor - ANSWER ✓ It converts x-ray photons to light and stores it.
Scintillators - ANSWER ✓ The amount of x-rays absorbed depends on the type of
scintillator.
Detector elements - ANSWER ✓ Detector elements are formed by voltage gates
that close at readout to stop the flow of electrons.
, Readout process - ANSWER ✓ The readout process requires that the flow of
electrons is timed and multiple voltage changes occur.
Types of noise affecting image quality - ANSWER ✓ The most common types of
noise that affects image quality include quantum noise, statistical noise, 'dark'
current noise, and amplification noise, except for quantum noise.
Clinical applications for CCDs - ANSWER ✓ Clinical applications for CCDs
include digital fluoroscopy, computed tomography fluoroscopy, digital
mammography, except for computed tomography fluoroscopy.
Comparison of CCD and CMOS - ANSWER ✓ When compared with a CMOS,
CCDs use more than 100 times the power.
Base material used in integrated circuits - ANSWER ✓ The most popular base
material used in integrated circuits is silicon.
Demagnification - ANSWER ✓ Demagnification is reducing the phosphor output
image to the size of the active area of the CCD.
CCD - ANSWER ✓ A detector in which each pixel has its own amplifier.
CMOS - ANSWER ✓ A highly efficient indirect conversion system that takes up
less fill space than CCDs.
Indirect conversion detector system - ANSWER ✓ Requires optical coupling and
image size reduction.
NASA-developed flat-panel detector technology - ANSWER ✓ CMOS.
Specialized pixels in a CMOS system - ANSWER ✓ When struck with x-ray
photons, the x-ray photons are converted into light, light photons are stored in
capacitors, and light photons are converted into electrical charges.
Quantum efficiency - ANSWER ✓ A measurement of the amount of electrons
produced relative to the incident light from the scintillator.
Edition EXAM QUESTIONS WITH
CORRECT ANSWERS||100%
GUARANTEED PASS||UPDATED
2025/2026 SYLLABUS||A+
GRADED||<<NEWEST VERSION>>
Image processor - ANSWER ✓ A device that processes the electrical signals from
the detector to create an image.
Noise cancelling - ANSWER ✓ The process of reducing unwanted signals in
image data.
Analog-to-digital conversion - ANSWER ✓ The process of converting analog
signals into digital format.
Readout - ANSWER ✓ The process of retrieving data from the imaging system.
Line scanning sequence - ANSWER ✓ The order in which the imaging system
scans the area to capture an image.
Amorphous silicon detector - ANSWER ✓ A type of detector used in digital
radiography.
CsI detector - ANSWER ✓ A detector that uses thin crystalline needles.
Light spread in CsI detectors - ANSWER ✓ There is very little light spread.
Gd2O2S scintillator - ANSWER ✓ Known as both 'Turbid' and 'Unstructured'
phosphor.
, Detector performance measurements - ANSWER ✓ Measured with spatial
resolution, observation of flow contrast objects in a phantom, and DQE.
Defective pixels - ANSWER ✓ Can result from chemical corrosion, static
discharge, and dust.
Standard for defective pixels - ANSWER ✓ Manufacturers aim for less than 0.1-
0.2% defective pixels.
Causes of image lag - ANSWER ✓ Include rapid succession images,
overexposure, and lack of beam attention.
Interpolation - ANSWER ✓ Uses information from surrounding pixels to 'fill in'
missing information.
Decreasing image lag - ANSWER ✓ Can be done by increasing the amount of
time between exposures.
Absorption material attachment - ANSWER ✓ Can be attached to the pixel array
electrically or physically.
2-D array in imaging - ANSWER ✓ Does not determine whether the imager is
direct conversion or indirect conversion.
Gain calibration - ANSWER ✓ Will remove inherent detector artifacts from an
image.
Offset correction - ANSWER ✓ Used to remove inherent signal that remains in a
detector.
Flat-panel detector systems - ANSWER ✓ Do not all have the ability to take
images faster than the detector can accommodate.
Direct image capture - ANSWER ✓ A method of capturing images directly
without intermediate steps.
Indirect image capture - ANSWER ✓ A method of capturing images that involves
intermediate steps.
,Spatial resolution - ANSWER ✓ A measurement of the ability to distinguish small
details in an image.
Observation of flow contrast objects - ANSWER ✓ A method to evaluate detector
performance.
DQE - ANSWER ✓ Detective Quantum Efficiency, a measure of detector
performance.
Chemical corrosion - ANSWER ✓ A potential cause of defective pixels in
detectors.
Static discharge - ANSWER ✓ Can lead to the occurrence of defective pixels.
Dust - ANSWER ✓ Can contribute to the presence of defective pixels.
Overexposure - ANSWER ✓ Can lead to image lag in radiographic imaging.
Underexposure - ANSWER ✓ Not a cause of image lag.
Charge-Coupled Device (CCD) - ANSWER ✓ It is the oldest indirect conversion
technology used in a variety of image capture applications.
Indirect conversion detector - ANSWER ✓ A device that acts like a camera in an
indirect conversion detector is known as a CCD.
Components that focus signals - ANSWER ✓ The components that focus the
signal from the scintillators to the CCD are called fiber optics.
Capacitor - ANSWER ✓ It converts x-ray photons to light and stores it.
Scintillators - ANSWER ✓ The amount of x-rays absorbed depends on the type of
scintillator.
Detector elements - ANSWER ✓ Detector elements are formed by voltage gates
that close at readout to stop the flow of electrons.
, Readout process - ANSWER ✓ The readout process requires that the flow of
electrons is timed and multiple voltage changes occur.
Types of noise affecting image quality - ANSWER ✓ The most common types of
noise that affects image quality include quantum noise, statistical noise, 'dark'
current noise, and amplification noise, except for quantum noise.
Clinical applications for CCDs - ANSWER ✓ Clinical applications for CCDs
include digital fluoroscopy, computed tomography fluoroscopy, digital
mammography, except for computed tomography fluoroscopy.
Comparison of CCD and CMOS - ANSWER ✓ When compared with a CMOS,
CCDs use more than 100 times the power.
Base material used in integrated circuits - ANSWER ✓ The most popular base
material used in integrated circuits is silicon.
Demagnification - ANSWER ✓ Demagnification is reducing the phosphor output
image to the size of the active area of the CCD.
CCD - ANSWER ✓ A detector in which each pixel has its own amplifier.
CMOS - ANSWER ✓ A highly efficient indirect conversion system that takes up
less fill space than CCDs.
Indirect conversion detector system - ANSWER ✓ Requires optical coupling and
image size reduction.
NASA-developed flat-panel detector technology - ANSWER ✓ CMOS.
Specialized pixels in a CMOS system - ANSWER ✓ When struck with x-ray
photons, the x-ray photons are converted into light, light photons are stored in
capacitors, and light photons are converted into electrical charges.
Quantum efficiency - ANSWER ✓ A measurement of the amount of electrons
produced relative to the incident light from the scintillator.
