carter questions ch. 2-10 (no ch. 8) Flashcards
an image formed by recording a continuous changing signal is know as
analog
the arrangement of pixels in rows and columns is known as
matrix
the amount of tissue included in the image is
field of view
the measurement of the radiation that was incident on the image receptor for a particular exposure is known as
K(ind)
the difference between the actual exposure and the target exposure is known as
DI
contrast resolution is a digital system’s ability to
show small differences in gray levels
true/false: dynamic range is the ability of a digital imaging system to respond to varying levels of exposure
true
true/false: spatial resolution in digital imaging is dependent on pixel size
true
true/false: the best component in a digital system will determine the resolution in a digital image
false
which of the following measures the efficiency of a system to convert the x-ray input signal into a useful output image?
-MTF
-DQE
-exposure latitude
-spatial resolution
DQE
The useful signal is determined during which part of the imaging cycle?
image sampling
true/false: the Nyquist theorem states that the sampling frequency must be less than twice the frequency of the input signal
false
true/false: aliasing occurs when the sampling frequency is not greater than twice the frequency of the input signal
true
in digital projection radiography, what process is used to normalize an image that has been taken with too great exposure?
automatic rescaling
true/false: The look-up table that is used to determine the brightness and contrast of an image is unique for each anatomic part
true
Which processing technique will amplify particular known frequencies in an image while suppressing others?
-edge enhancement
-high-pass filtering
-masking
all of the above
true/false: Window width controls the brightness of the image on the display
false
true/false: Shuttering the digital image will reduce the exposure to the patient
false
Which processing parameter will put together multiple images into one single image for display?
image stitching
The active layer in a PSP plate is usually made of phosphors from what family group?
barium fluorohalide
Which layer of the PSP plate sends light in a more forward direction when released in the reader?
reflective
Which layer of the PSP plate reduces static electricity?
conductive
true/false: the barcode label is used by the reader to identify the PSP plate
true
The laser excites the electrons trapped in the phosphor centers so that the energy may be released in the form of
light
What device in the reader detects the light being released from the PSP plate during reading?
photodetector
The PSP plate is erased…
-after every PSP plate is read
-by flooding it with bright light
-manually by selecting the proper eraser method
all of the above
true/false: too much mAs will cause quantum mottle
false
true/false: if grid lines are present and run parallel to the scanning laser, the image will not have the moire pattern present
false
true/false: overexposure will reduce the contrast resolution
true
After processing the image, strange artifacts are present that look metallic but are not present on the patient or table. The cause could be…
the cassette was backward
true/false: A thorough cleaning of the light guide by the technologist will remove white lines parallel to the plate travel
false
true/false: Dark line artifacts can be caused by too much kVp in an exposure
true
true/false: The only way to get two overlying images is to double expose the cassette.
false
***A photo conductor absorbs _____ and produces ____________
x-rays, electrical charges
Which of the following is not considered a scintillator?
-gadolinium oxide
-cesium iodide
-amorphous selenium
amorphous selenium
Which of the following is used as a photodetector?
–gadolinium oxide
-cesium iodide
-amorphous selenium
-a-Si:H
a-Si:H
which of the following are not found in an AMFPI?
-a-Si TFT with CsI
-a-Se with TFT
-PSP
-Scintillator
PSP
which detectors convert x-ray energy directly into electrons?
a-Se with TFT
a gadolinium oxide scintillator is known as what type of phosphor?
turbid, unstructured
true/false: Gain calibration will remove inherent detector artifacts form an image
true
true/false: Offset correction is used to remove inherent signal that remains in a detector
true
what can be done to decrease the change of having image lag occur in the next image?
Increase the amount of time between exposures
Which type of absorbing material requires a capacitor as the storage element?
-a-Se
-photoconductor
-scintillator
A-Se and photoconductor
A charge-coupled device (CCD) does all of the following except
-reduce size of projected light image
-transfer the image to a capacitor
-convert light into x-ray photons
-act as receptors via lenses or fiber optics
convert light into x-ray photons.
The amount of electron/hole pairs is related to the amount of
light absorbed
The layer in a CCD chip that contains the electron gates is the
polysilicon layer
The insulating layer in a CCD chip is the
silicon dioxide layer
a system that used scintillators that convert x-rays to light and light to electric charge and stores the charge in capacitors is known as a
CMOS
A solid chemical element or compound doped with impurities that make it highly conductive is known as a
semiconductor
true/false: most CMOS detectors use both N-type and P-type transistors to form the electrically controlled gate
true
Which of the two technologies, CCD or CMOS, is more susceptible to noise, has a lower light sensitivity, uses very little power, and is inexpensive to manufacture?
CMOS
A generic term that is used to describe a programmable electronic device that can store, retrieve, and process data is a
computer
how many bits are in a single byte?
8
What keeps the radio frequencies generated within the computer electronics from interfering with outside devices?
the case
What is the largest circuitry board inside the computer?
motherboard
What device runs the startup diagnostics during boot-up of the computer?
BIOS
true/false: Random access memory (RAM) will retain stored information after the computer has been shut down
false
What is considered the most versatile type of port found on a computer?
USB
true/false: The network card is designed to take the brunt of the force during a power surge
false
Which of the following are types of computer mice?
-infrared
-mechanical
-optical
all of the above
which type of monitor is most common in hospitals
LCD
In which type of workstation can changes not be made to the patient demographics of an image set?
review station
what does MIMPS stand for?
medical image management and processing system
Which PACS device stores the historic image data to be viewed along with current studies?
archive server
In which PACS architecture is the archive the central repository for all images?
client/server
true/false: in a web-based system, images are sent directly from the modality to a display workstation for image interpretation.
false
true/false: Monitor type and configuration is of no concern when implementing a PACS in a radiology department
false
What workstation function will allow the user the ability to arrange a certain number of images per monitor per modality?
hanging protocols
Which advanced image manipulation function will allow the radiologist to view several different anatomical planes from the original acquired sagittal images?
multiplanar reconstruction
Which advanced image manipulation function will allow the technologist to join multiple images together as one?
stitching
What part of the archive contains the master database of everything contained within the archive?
image manager
What part of the archive contains the physical storage of images within the archive?
-image manager
-image storage
-archive server
both B and C
What term is used to describe a layer of archive storage?
tier
The term RAID stands for
redundant array of independent disks
Which RAID configuration is a special-purpose network of storage devices?
SAN
What device will scan an analog x-ray film into a PACS?
film digitizer
What do dry imagers use to process the latent image on the film?
heat
Which RAID configuration is directly attached to a network?
NAS
Which RAID level is often seen in PACS archives?
5
Which of the following are considered long-term storage devices?
-MOD
-DVD
-DLT
-RAID
all of the above