flashcards
Q: Which of the following terms refers to the rate of light striking a surface?
A: illuminance
Q: Who primarily uses diagnostic (primary reading) workstations?
A: radiologists
Q: Which of the following is used to monitor possible trends in imaging errors?
A: repeat/reject analysis
Q: When completing quality control of images, which of the following reasons would cause an image to be suboptimal?
A: poor collimation
Q: Which of the following is the correct meaning of the acronym RAID?
A: redundant array of independent disks
Q: Which of the following best describes how a dead pixel appears on a monitor?
A: white dots on a black background
Q: Which of the following best describes how a stuck pixel appears on a monitor?
A: black dots on a solid white background
Q: What is the specific name of the test pattern represented in this image?
A: SMPTE
Q: Which of the following holds the patient’s full medical information?
A: HIS
Q: Which of the following PACS quality control tests ensures all images acquired at the modality are successfully received by PACS?
A: Data Integrity
Q: Which of the following are performed when x-ray equipment is performing poorly or having issues?
A: Error maintenance
Q: Which of the following describes the series of lines of unique data/information attached to every image?
A: DICOM header
Q: Which of the following quality control issues is evaluated by checking that straight lines appear straight and the overall shape of the image is not distorted?
A: Geometric distortion
Q: PSP plates should be erased every:
A: 48 hours
Q: Teleradiology refers to:
A: Interpretation of medical images off site
Q: What is the specific name of the test pattern represented in this image?
A: TG18-QC
Q: Which of the following PACS quality control tests determines whether there is any loss of information on the compressed image?
A: Compression recall
Q: When performing quality testing on digital imaging IRs, which of the following is used to describe the spatial resolution?
A: lp/mm - line pairs per millimeter
Q: Which of the following type of compression results in no image degradation and is used when storing medical images?
A: lossless
Q: Which term describes the process of a PAC system automatically anticipating the need for previously completed images and have them available before the next scheduled exam?
A: prefetching
Q: Which of the following generally CANNOT be performed in PACS?
A: stitch an image
Q: Which of the following is(are) the role(s) of a PACS image manager?
A: All of the above
Q: Which of the following describes the process of making copies of each tape or disk of images and storing them in a separate location, so images are not lost due to a fire or natural catastrophe?
A: disaster recovery
Q: Which of the following are the two main types of film digitizers?
A: laser and CCD
Q: Which of the following is a QC activity performed in a PACS environment?
A: all of the above
Q: CQI focuses on _______ the process and QA and QC programs focus on _______ quality.
A: improving ; maintaining
Q: Which of the following is a disadvantage of LCD monitors?
A: limited off-angle viewing
Q: Which of the following is the correct meaning of the acronym PACS?
A: Picture Archiving and Communication System
Q: Which of the following is the correct meaning of the acronym RIS?
A: Radiology Information System
Q: Which of the following is the correct meaning of the acronym HIS?
A: Hospital Information System
Q: As the number of pixels on a monitor decreases, what happens to the resolution?
A: decreases
Q: Which of the following is assigned by RIS and is used to identify a particular procedure or exam?
A: accession number
Q: Which of the following PACS quality control tests assesses how quickly images are retrieved from the archive to the workstation?
A: image transfer speed
Q: Which of the following PACS quality control tests check the loading speed of a radiographic exam, including opening the exam, paging through the images, and performing an image processing function?
A: workstation processing speed
Q: What program is responsible for monitoring the performance of x-ray equipment to ensure proper function?
A: QC
Q: Which of the following tests are performed on newly installed equipment or after equipment has been repaired?
A: acceptance testing
Q: Which of the following tests are performed to ensure that equipment is performing as expected on a regular basis?
A: routine maintenance
Q: Which of the following is a realistic target for an overall repeat rate?
A: 3-5%
Q: When should a technologist notify a manager or clinical engineer of artifacts related to IRs, CR readers, or monitors?
A: immediately
Q: Which of the following describes the monitor’s ability to accurately display different shades of brightness from a test pattern?
A: luminance response
Q: Which of the following terms refers to the rate of light striking a surface?
A: illuminance
Q: What preprocessing function is responsible for figuring out how many images are on a CR plate so they can be treated separately by the reader?
A: segmentation (also known as PPR)
Q: What term describes a sub-matrix that is applied over a larger matrix to mathematically fill dead pixels?
A: kernel
Q: Which description best defines a histogram?
A: Graph where the x-axis is the pixel value (exposure read) and the y-axis is the number of pixels
Q: Which of the following can negatively affect the histogram analysis?
A: collimation errors
Q: Which of the following terms describes a set of instructions, especially in a computer program?
A: algorithm
Q: Which of the following is determined by finding the SMIN and SMAX of the histogram?
A: values of interest
Q: Which of the following is the correct definition of automatic rescaling?
A: Refers to the initial round of default processes to make the image appear “normal” (aligns the brightness of the image)
Q: Which of the following terms describe corrections that are made to the “raw” digital image data due to physical flaws in image acquisition?
A: pre-processing
Q: Which of the following terms describe refinements of the image after corrections have been made for data acquisition? These are somewhat subject to personal preference.
A: post-processing
Q: Which of the following type of histogram analysis compares the exposure to a single standardized data set and would be used for an abdominal x-ray?
A: Type 2
Q: Which of the following type of histogram analysis would be used in a barium study?
A: Type 3
Q: Which type of histogram analysis uses image data from approximately 50 actual clinical procedures to update the reference histogram to a new “ideal” histogram?
A: Neural
Q: After the histogram is created, what is the area called that includes the pixel values that will be included in the final image?
A: values of interest
Q: At least ______ times the number of pixels needed to form the image must be sampled.
A: two
Q: Window level (WL) controls the overall ____________ of the image.
A: brightness
Q: What is it called when the dels in a particular area of the IR have reached the maximum electrical charge that they can store?
A: saturation
Q: What is it called when a digital image is separted into a tissue only image and a bone only image?
A: dual-energy subtraction
Q: Which of the following is the correct statement?
A: Shuttering/cropping can be used to remove the white border around an image.
Q: Which speed class with have less exposure to the image receptor, which results in more noise in the image?
A: 400
Q: Which of the following will be the result when the slope of the LUT is increased (more straight up and down)?
A: shorter scale of contrast
Q: Which of the following will be altered when the line of the LUT is moved up or down the vertical side (y-axis) of the graph?
A: brightness
Q: Which of the following describes amplification of the high-frequencies of the areas of interest? This makes the edges of any anatomical part stand out more.
A: edge enhancement
Q: Referring to the processing domains, which of the following best describes the intensity domain?
A: sorting the image strictly by the pixel values
Q: Referring to the processing domains, which of the following best describes sorting by frequency?
A: sorting the image strictly by the size of the objects
Q: Which post-process option can be used to adjust the contrast of the image?
A: window width
Q: Which post-processing function is most likely to increase the visible appearance of image noise?
A: high-pass filtering
Q: Which of the following will most likely produce the highest quality radiographic image?
A: high SNR
Q: Which of the following post-processing functions is NOT acceptable?
A: cropping exposed anatomical information from the original image
Q: Which domain sorts objects according to location?
A: spatial
Q: Which of the following removes high-frequency noise?
A: smoothing
Q: As speed class increases:
A: the likelihood of noise increases
Q: The use of smoothing may result in which of the following?
A: loss of fine detail
Q: Equalization (dynamic range compression) primarily affects which of the following?
A: contrast distribution
Q: What is another name for smoothing?
A: low-pass filtering
Q: In digital radiography, which has the greatest influence on displayed image contrast?
A: LUT
Q: Which processing parameter will put together multiple images into one single image for display?
A: image stitching
Q: Which general term describes the refinement of the gray scale image by the input of data into the look-up tables?
A: gradation processing
Q: During the histogram image analysis process, which of the following can cause a type 3 histogram to be produced?
A: positive iodinated contrast or barium
Q: How would the histogram appear for an image with a long scale of contrast?
A: The histogram would be wide.
Q: In digital imaging, what process is used to normalize an image, regardless of the exposure?
A: automatic rescaling
Q: What does the acronym TFT stand for?
A: thin-film transistor
Q: The pixel size formula applies to which of the following matrices?
A: soft image of a magnified image
Q: Which of the following is made up of two metal oxide semiconductors?
A: CMOS
Q: Which of the following statements is true?
A: CCDs typically have a higher fill factor compared to CMOS
Q: CCD and CMOS detectors are used in which type of digital radiography system?
A: indirect conversion
Q: Which type of digital radiography detector contains complete readout electronics within each detector element (DEL/dexel)?
A: CMOS
Q: Which of the following can be the cause of artifacts in CR?
A: all of the above
Q: Which type of CR reader captures light from both sides of the IP?
A: dual-sided reader
Q: In a CR reader, which of the following collects the light being released from the imaging plate?
A: photomultiplier tube
Q: What represents the latent image in a PSP CR system?
A: Electrons trapped in “F” centers
Q: Which of the following terms refers to the immediate emission of light during stimulation?
A: fluorescence
Q: Following red laser stimulation in CR, what happens to electrons trapped in F-centers?
A: They return to lower energy orbital shells, releasing light
Q: Which term describes the direction of plate movement through the reader?
A: sub-scan (slow scan)
Q: Which term describes the direction of laser beam movement across the CR imaging plate?
A: fast scan
Q: In CR, which term describes the percentage of absorbed x-ray energy converted into visible light?
A: conversion efficiency
Q: Once x-ray or light photons are absorbed in a detector element (DEL), what percentage is typically converted into electrical charge?
A: nearly 100%
Q: Which term describes the concept that sampling frequency must be at least twice the highest spatial frequency present in the image?
A: Nyquist frequency
Q: All of the following are considered scintillators EXCEPT:
A: amorphous selenium
Q: Which of the following describes the complete process regarding flat-panel detectors that use indirect conversion technology?
A: x-rays to light to electrical signals
Q: Which of the following describes the complete process regarding flat-panel detectors that use direct conversion technology?
A: x-rays to electrical signals
Q: Which of the following is used in direct conversion flat panel detectors?
A: amorphous selenium (a-Se)
Q: Which of the following is true regarding cesium iodide detectors?
A: reduced light spread increases spatial resolution
Q: Which of the following is made up of small crystals in an unstructured or turbid layers?
A: gadolinium oxysulfide
Q: Which of the first layer of a CR imaging plate?
A: protective layer
Q: Where is amorphous silicon used within digital radiography?
A: indirect conversion FPDs
Q: Which of the following measures the overall efficiency of a system to convert the x-ray input signal into a useful output image?
A: detective quantum efficiency
Q: Which of the following terms/units is used to express the resolution of a digital image?
A: line pairs per millimeter
Q: In a DR flat panel detector, assuming TFT and capacitor size remain constant, increasing DEL size will result in:
A: higher fill factor
Q: In FPDs, which part is responsible for the del’s ability to store an electric charge?
A: capacitors
Q: In FPDs, which of the following acts as a switching gate to release the electrical charge when the del is read out?
A: TFTs
Q: Which of the following is true regarding direct conversion compared to indirect conversion flat panel detectors?
A: direct-conversion has better spatial resolution than indirect-conversion
Q: Which of the following is a correct statement regarding direct-conversion versus indirect-conversion?
A: indirect-conversion typically has a higher DQE than direct-conversion
Q: What does it mean if a detector element (DEL) has a fill factor of 80%?
A: 80% of the DEL is devoted to sensing
Q: Which of the following is used by direct conversion DR?
A: photoconductors
Q: All of the following can be used in indirect conversion DR EXCEPT:
A: photoconductors
Q: Which of thefollowing controls the order in which the DELs are read out in DR image receptors?
A: gate lines
Q: An ideal or perfect digital imaging system would have a DQE of:
A: 1.0
Q: What is the maximum amount of time that an IP should be allowed to sit before being read? A delay can result in a decrease in the photostimulable luminance (PSL).
A: 8 hours
Q: Which of the following makes up the phosphor layer of the CR imaging plate?
A: barium fluorohalide doped with europium
Q: During CR image processing, which of the following is used to release electrons trapped in the F-centers for image readout?
A: red laser
Q: What is the percentage of image deterioration that can occur if the IP is not read within 8 hours?
A: 25%
Q: The PSP imaging plate is composed of:
A: photostimulable phosphor
Q: Which of the following processes is used to erase any remaining trapped electrons on the PSP imaging plate?
A: bright light
Q: Which of the following terms refers to any emission of light?
A: luminescence
Q: Which of the following terms refers to the delayed emission of light?
A: phosphorescence
Q: In DR, what is the area of the del called that receives (absorbs) the x-ray photons? (Hint: This area is typically described in a percentage.)
A: fill factor
Q: In DR flat-panel detectors, where is the charge stored?
A: capacitor
Q: Which of the following if the BEST ANSWER to describe the detector element in the DR image receptor?
A: del
Q: Which of the following can be the cause of CR artifacts that appear consistently on all images?
A: computer hardware and software
Q: In order to prevent the aliasing, the Nyquist Theorem states that the sampling frequency must be how many times more than the spatial frequency of the image being sampled?
A: two
Q: Which type of material is used in the active detection layer of an indirect conversion flat panel detector?
A: amorphous silicon
Q: Which of the following is the correct description of detective quantum efficiency (DQE)?
A: measurement of the overall efficiency with which a detector can convert input exposure into a useful output exposure
Q: Which of the following detector types has the highest detective quantum efficiency (DQE)?
A: indirect conversion using cesium iodide as scintillation material
Q: Which type of CR reader reads an entire line of the imaging plate at a time, one side of the imaging plate?
A: line scan
Q: Scanning the bar code on a PSP plate is extremely important because it links the image data with the correct:
A: patient information
Q: Which category best describes CCD and CMOS technology?
A: indirect conversion
Q: Which of the following describes the movement of a laser moving across the IP?
A: fast scan
Q: Which of the following is responsible for absorbing x-rays and producing electrical charges?
A: photoconductors
Q: Which of the following best describes the structural form of cesium iodide used in indirect conversion detectors?
A: columnar (needle-like crystals)
Q: Which of the following layers of the CR imaging plate traps electrons during exposure?
A: active
Q: Which of the following characteristics are associated with an image receptor that has a wide (greater) dynamic range?
A: longer gray scale and wide exposure latitude
Q: If we have a shorter scale of contrast (less grays), how will this affect contrast resolution?
A: There will be decreased (worse) contrast resolution.
Q: What is the pixel size for a 30mm FOV and 512x512 matrix size?
A: 0.06mm pixel
Q: Which of the following terms describes the pattern of boxes laid out in rows and columns over an entire image?
A: matrix
Q: What is the correct formula used to calculate pixel size?
A: pixel size = FOV / matrix
Q: Which of the following terms describes part of digitizing an image where the intensity of light or radiation from each designated pixel area is measured by the detector?
A: sampling
Q: Which of the following is a correct statement if the bit depth changes from 2⁸ to 2¹⁶?
A: If the bit depth is increased, there will be more available grays.
Q: What term describes a set of preprogrammed instructions to execute a single, specific task?
A: algorithm
Q: If the size of the matrix increases (or gets bigger), what happens to the pixel size? (FOV remains the same)
A: pixel size decreases
Q: If the FOV remains the same, what happens to the size of the image matrix if the pixel pitch decreases, the number of pixels increases and the spatial resolution increases.
A: matrix size increases
Q: Which term is the ability of the system to record available spatial frequencies? A perfect system is 1 or 100%
A: modulation transfer function
Q: Which term describes how efficiently a system converts the x-ray input signal and converts into a useful output image?
A: detective quantum efficiency
Q: Which of the following best describes SNR?
A: As SNR increases, noise decreases, but exposure increases to the patient.
Q: Which of the following terms describes the distance from side to side in one pixel?
A: pixel size
Q: Which of the following will result in better spatial resolution for a digital image?
A: large matrix and small pixel size
Q: What is the result if the pixel bit depth is increased (becomes larger)?
A: contrast resolution is increased (long scale of contrast)
Q: How many bits typically make up a byte?
A: 8
Q: Which of the following will result in a smaller pixel size?
A: 254mm FOV and 1024x1024 matrix
Q: Which term describes represents the “ideal” amount of x-ray exposure at the detectors?
A: target exposure indicator
Q: Which of the following terms describes the distance from the center of one pixel to the center of the adjacent pixel?
A: pixel pitch
Q: Which of the following determines the available greys for each pixel?
A: bit depth
Q: If the FOV stays the same and the matrix size decreases, what happens to the pixel size?
A: increases
Q: What term describes how many pixels are contained within a given area?
A: Pixel Density
Q: What is the pixel size for a 80mm FOV and 512x512 matrix size? (Rounded to the nearest tenth)
A: 0.2 mm pixel
Q: If we have a longer scale of contrast (more grays), how will this affect contrast resolution?
A: There will be increased (better) contrast resolution.
Q: Which term describes the exposure at the detector? This will be different for every x-ray image you take.
A: exposure index
Q: Different x-ray equipment manufacturers use different exposure indicator terms to evaluate detector exposure.
A: True
Q: Assuming the FOV does not change, which of the following happens as the matrix size increases?
A: increased spatial resolution
Q: Which of the following terms is known as a 3D element that describes a tissue slice using height, width and depth?
A: voxel
Q: Which of the following domains can sort information based on the location of the pixels within the coordinates of the matrix?
A: spatial
Q: Which of the following is uses histogram data to assign gray values to the image?
A: LUT
Q: Which process compresses the gray scale range and may eliminate extreme values?
A: DRC
Q: Which of the following post-processing functions reduce noise & softens the edges of details?
A: smoothing
Q: Which of the following describes the ratio of useful signal compared to non-useful noise in the acquired image data?
A: SNR
Q: Which of the following postprocessing functions removes low-frequency artifacts that occur in one direction across the image? This is primarily used when a stationary grid is present.
A: grid line suppression
Q: Which of the following should be avoided when taking an image?
A: dose creep
Q: Which of the following are post-processing options that can be performed by a technologist?
stitching
shuttering
automatic rescaling
histogram analysis
magnification
segmentation
A: 1, 2, and 5 only
Q: Which of the following is the correct sequence of events when taking an x-ray?
histogram is created
contrast & brightness adjustments are made by the LUT
pixel/del values are assigned
automatic rescaling occurs
A: 3, 1, 4, 2
Q: Which of the following results after the DRC (dynamic range compression) is applied to the image?
A: image contrast increases
Q: Which of the following describes the range of pixel values from the histogram that represent the anatomy of interest?
A: VOI
Q: Which of the following detector calibration steps evens out the overall signal or brightness across the entire image?
A: flat-field uniformity
Q: Generally, how would the histogram appear if it contained a long scale of contrast?
A: The histogram would be wide.
Q: In a histogram graph of a digital image, the vertical height of a data point along the plotted curve indicates the:
A: number of pixels possessing a specific value
Q: Referring to the processing domains, which of the following best describes the intensity domain?
A: sorting the image strictly by the pixel values
Q: The term pre-processing best describes all the computer algorithms, which are designed to:
A: correct for errors and limitations in the image acquisition system
Q: The use of smoothing may result in which of the following?
A: loss of fine detail
Q: What is another name for edge enhancement?
A: high-pass filtering
Q: Which of the following can occur when the dynamic range or bit depth of an image is limited?
A: data clipping
Q: Which of the following is determined by finding the Smin and Smax of the histogram?
A: values of interest
Q: Which of the following is the correct definition of segmentation?
A: Tries to recognize the borders of multiple images on the image receptor
Q: Which of the following post-processing functions is used to remove the white border around the image?
A: Shuttering or masking
Q: Which of the following terms describe corrections that are made to the “raw” digital image data due to physical flaws in image acquisition?
A: pre-processing
Q: Which of the following varies on every image taken by a technologist and is used to prevent dose creep?
A: exposure index
Q: Which of the following will be the result when the slope of the LUT is decreased?
A: longer scale of contrast
Q: Which of the following will most likely produce the lowest quality radiographic image?
A: low SNR
Q: Which post-processing technique removes small artifacts that are fairly consistent in size and occur in a regular pattern across the image?
A: periodic noise reduction
Q: Which type of histogram analysis is typically used for extremity imaging such as an ankle?
A: Type 1
Q: Which of the following is the correct definition of exposure field recognition?
A: Used to identify the black background from raw x-ray beam exposure outside the anatomy
Q: Which of the following is constructed by counting the number of pixels and the values assigned to the pixels?
A: histogram
Q: Which of the following best describes the purpose of a histogram in digital radiography?
A: to display the distribution of pixel exposure values
Q: Which of the following describes high-pass filtering allowing fine edges of structures to stand out?
A: edge enhancement
Q: The image manager in a PACS is responsible for which of the following functions?
A: All of the above
Q: What is a storage area network (SAN) in medical imaging?
A: A dedicated high speed network that provides access to centralized storage
Q: How does a client-server system operate in medical imaging?
A: The server stores and manages data, and clients request access to that data
Q: Which of the following terms describes the brightness of a display monitor?
A: luminance
Q: Which of the following describes the standard process for transmitting medical images and their associated information?
A: DICOM
Q: If the overall repeat rate is 10%, is this within the recommended repeat range?
A: No, the repeat rate is too high
Q: Which function determines how images are deployed or viewed on the radiologist’s monitors?
A: hanging protocols
Q: Which device scans an analog film so it can be stored electronically?
A: digitizer
Q: Which device is used to measure light intensity on a monitor?
A: photometer
Q: Which type of image compression permanently removes some image data, potentially affecting diagnostic quality?
A: lossy
Q: Which system is primarily used to store a patient’s overall medical history, including notes, medical imaging reports, medications, and lab results?
A: EMR
Q: Why has the term PACS been largely replaced by MIMPS in regulatory language?
A: Because the FDA separated PACS into distinct categories, including MIMPS, storage devices, and communication devices
Q: What is health informatics?
A: The use of data systems to improve patient care
Q: Which of the following describes how evenly a display produces brightness across the entire screen?
A: Luminance uniformity
Q: Which of the following contains the receipt, storage and distribution of images from all medical imaging disciplines?
A: PACS
Q: Which of the following describes a software standard for exchanging electronic text information in compatible formats between healthcare systems and departments?
A: HL7
Q: Which of the following describes the process of a computer analyzing densities on the image and alerting a radiologist to questionable densities?
A: computer-aided diagnosis
Q: Which of the following can provide the most up-to-date PACS hardware and software to a smaller institution that cannot afford it?
A: ASP
Q: The rate of light striking a surface is defined as:
A: Illuminance
Q: A computer network limited to relatively small geographic area is known as a:
A: LAN