Modules 1-11

Card Set Information

Modules 1-11
2013-04-28 14:48:56
Summer Technical Review

This is a compilation of the checkpoint questions throughout the 11 modules. Do no rely solely upon these cards. last revised summer2012
Show Answers:

  1. T/F: 
    Increasing kVp increases the number of x-rays that the x-ray tube emits.
    • True: Increasing kVp increases the number of
    • interactions that occur inside the anode of the x-ray tube. This creates more x-ray photons. The photons that are created also have increased energy.

  2. T/F:  Theprimary reason filtration is added to the x-ray beam is to decrease patient dose.
    True: Filtration removes weak x-rays that add very little information to the radiographic image. These x-rays are absorbed by the patient and contribute a great deal to patient dose.
  3. T/F Doubling your distance from a radiation source cuts your radiation exposure in half.
    False: Doubling your distance from a radiation source would reduce your radiation exposure to 1/4 of your original exposure.
  4. T/F: The primary reason the x-ray beam weakens as it travels away from the x-ray tube is attenuation of the beam in air.
    False: The primary reason why the x-ray beam loses its intensity as it travels away from the x-ray tube is divergence of the beam.
  5. T/F Using tighter collimation will reduce"undercutting."
    • True: Reducing field size will reduce the amount of raw radiation striking the IR. This will reduce the effects of
    • undercutting.
  6. T/F Reducing kVp, using a grid and increasing  collimation all reduce the production of scattered radiation?
    False: Although grids reduce the amount of scattered radiation reaching the IR, they do not reduce the production of scattered radiation.
  7. T/F The main purpose of a grid is to improve radiographic contrast?
    True: scattered radiation strikes the lead strips of the grid and is absorbed. this prevents a large percentage of the scattered radiation from reaching the IR and contrast is improved.
  8. T/F Grids transmit approximately 96% of the primary beam.
    • False: Approximately 60% of the primary beam is transmitted through an anti-scatter grid. For this reason radiographic
    • techniques must be increased when using them.
  9. T/F Gridlines are less of a problem in digital
    radiography imaging than in analog imaging.
    • False: because digital systems are better able to produce diagnostic quality films with shorter exposure times in certain
    • situations, grid lines can become more of a problem when they are used.
  10. T/F: Grid cut-off increases the amount ofprimary radiation that reaches an image receptor.
    False: When grid cut-off occurs, primary radiation is absorbed by the lead strips of grid and less of the primary signal reaches the receptor.

  11. T/F: The Moiré pattern occurs more often when
    using a short dimension grid than when using a long dimension grid.
    True: Moiré patterns occur more often when short dimension grids are used because the grid lines coincide with the direction of the laser beam scan in the plate reader.

  12. T/F: The most intense aspect of an x-ray beam is
    located on the cathode side.
    • True: x-rays that exit the tube on the anode side must navigate through a portion of the anode material. This weakens the
    • anode side of the beam.
  13. T/F: X-rays are a type of electromagnetic
    True: x-rays are found on the electromagnetic spectrum and travel in waves much like light photons.
  14. T/F: A Compton Scatter interaction takes place
    between an x-ray and an outer shell electron.
    True: When an x-ray photon knocks and inner shell electron out of orbit, photoelectric absorption would occur.
  15. T/F: Pleural effusion is considered a destructive pathology.
    • False: Pleural effusion occurs when fluid fills the pleural cavity where the lungs sit. Therefore, this is an additive
    • pathologic condition.
  16. 16. T/F: Fat and muscle tissues are both significant sources of image noise.
    True: Fat and muscle tissue both produce scatter radiation when struck by the primary beam.

  17. T/F: A high signal-to-noise ratio (SNR) is required to produce a quality image.
    True: A high SNR means that more of the x-ray beam reaches the IR, compared to undesirable scatter radiation.

  18. T/F: Using collimation reduces the amount of noise reaching the image receptor but increases patient dose.
    • False: beam restriction decreases noise to the image receptor and lowers the patient dose by reducing the amount of tissue
    • exposed to the radiographic beam.

  19. T/F: Patient information is captured in the emulsion layer of radiographic film.
    True: The emulsion layer of radiographic film is responsible for capturing patient information.
  20. T/F: "Latent Image" is the term used to describe the radiographic image seen on a viewbox illuminator.
    False: the term "latent image" is associated with the invisible image present on the film after exposure.
  21. T/F: The phosphor level is the functional layer of a typical x-ray intensifying screen.
    True: the phosphor layer of the intensifying screen interacts with x-rays to produce light that exposes the radiographic film.
  22. T/F: A canister filter in the replenishment system helps remove sludge and debris from the operating developer solution.
    False: the recirculation system filters the operating developer solution.
  23. T/F: Rollers in the processor transport system trigger replenishment of operating solutions in the automatic film processor.
    True: the film transport system entrance rollers interface with a microswitch that triggers processor chemical replenishment.
  24. T/F: Guide shoe plates are only found in large solution transport rack assemblies.
    False: Guide shoe plates are also found in crossover rack assemblies.
  25. T/F: The acidifier in the developer solution provides the proper medium for optimum developer activity.
    False: The acidifier is an essential component of the Fixer solution.
  26. T/F: The fixer solution removes underexposed and underdeveloped silver halide crystals from the film emulsion.
    True: This is the function of the clearing agent in the fixer solution.
  27. T/F: In a typical automatic film processor, films spend the greatest amount of time immersed in the developer solution.
    True: Film will spend the greatest amount of time,  approximately 20-15 seconds, immersed in the developer solution, less time in contact with the fixer and wash bath solutions.
  28. T/F: Rollers in crossover assemblies are more likely to be the source of film artifacts than transport rollers in solution tank assemblies.
    True: crossover rollers are out of solution rollers that are prone to developing crusts and debris that can be transferred to film surfaces as they are processed.
  29. T/F: Emulsion pickoff does not occur when processing dual-emulsion films using an automatic film processor.
    False: pick-off occurs on dual-emulsion films, it's just not as apparent as pick-off on single-emulsion films.
  30. T/F: Developer temperature should be part of daily sensitometric processor monitoring.
    True: Daily monitoring is essential because slight changes in developer temperature severely affect the opacities of processed film images
  31. T/F: The daily mid-step density is measured on a sensitometer step with a density reading as close to 1.0 plus base plus fog,
    no matter what step is used.
    False: The daily mid-step density should be measured using the same step.
  32. T/F: Base plus fog is measured using a calibration of the background opacity of a radiographic film.
  33. T/F: Films handled in the darkroom are safe from exposure because light that a safelight emits is safe.
    False: Extended exposure to safelightillumination fogs radiographic film.
  34. T/F: The cassette-based digital image receptor uses storage phosphor technology to create the image.
    True: Computed Radiography plates are made of phosphors that capture the energy of the x-ray beam and release the energy during the processing phase.

  35. T/F: A digital image is composed of a series of
    rows and columns known as a matrix.
    True: a matrix is made up of all the pixels in a digital image arranged in rows and columns.
  36. T/F: The brightness of a digital image is the equivalent of the term density used to describe the appearance of analog
    True: the computer algorithms used to create the digital image can somewhat compensate for underexposure or overexposure; therefore the visual cues of dark and light images do not apply in computed radiography.
  37. T/F: Calcium tungstate is a phosphor material used for intensifying screens.
    True: calcium tungstate, non-calcium tungstate, and rare earth are three phosphor types used in intensifying screens today.
  38. T/F: Relative speed measures the amount of exposure needed to achieve a specific optical density.
  39. T/F: The lower the exposure level needed to achieve a specific optical density reflects an increase in the receptor speed.
    • True: relative speed refers to how much exposure is needed to create an acceptable image. In order to compare screens, a
    • measured density of 1.0 above base+fog is used.
  40. T/F: The silver halide component of film is suspended in a gelatin emulsion.
    True: Silver halide crystals are suspended in gelatin. this allows the processing chemicals to interact with the silver halide crystals more efficiently.
  41. T/F: Direct exposure radiographic film has a lower silver content than film used with intensifying screens.
  42. Q: The ability of a digital imaging system to accurately create an output signal that matches the input signal is known as:
    detective quantum efficiency
  43. Q: The term used to describe the speed of a digital imaging system is: 
    speed class
  44. T/F: The photostimulable phosphor stores the energy deposited by the x-ray beam in the plate.
    True: the photostimulable phosphor is a storage phosphor.
  45. T/F: Flat-panel image receptors are classified as
    scintillator based or non-scintillator based.
    True: a scintillator is a device that absorbs x-ray photons and releases light photons. some flat-panel detectors use a scintillator and some do not.
  46. Q: The portion of the flat-panel detector receptor that is responsible for collecting individual electrons is the:
    thin film transistor (TFT)
  47. T/F: The actual matrix of the flat-panel detector
    is composed of DEL's.
    True: detector elements (DELs) are the portion of the TFT that collects electrons and produces an individual pixel.
  48. T/F: The number of electrons deposited in the DEL corresponds to the amount of radiation that strikes each area.
    True: individual DELs contain charges (number of electrons) proportional to the x-rays that strike each one.
  49. T/F: CCD is the acronym for charge-coupled device.
    True: the CCD is another form of direct image capture that differs from PSP or FPD technology.
  50. T/F: A CCD-based receptor requires the use of a
    scintillator material.
    True: the CCD uses a scintillator to produce light photons.
  51. T/F: A lens focuses the light produced by the scintillator onto a CCD.
    True: the light photons released by x-rays striking the scintillator reflect of a mirror to a lens that focuses the energy onto the CCD.
  52. T/F: Gas filled CT detectors have a smaller acceptance angle than scintillator based CT detectors.
    True: gas-filled detectors have smaller acceptance angles, meaning they are less sensitive to radiation than scintillator-based detectors.
  53. T/F: CT scanners can produce images with greater contrast than many image receptors used in diagnostic imaging? 
    True: the tightly collimated x-ray beam in CT decreases scatter, which increases image contrast.
  54. T/F: When comparing two receptors, the receptor with the highest DQE can produce an optimal image with less radiation exposure?
    • True: DQE is a measure of how efficiently an image receptor can reproduce the image signal. a high DQE means that this will
    • occur more efficiently, therefore a lower dose to the patient is necessary.
  55. T/F: Increased absorption efficiency increases the DQE of a receptor.
  56. T/F: Spatial resolution relates to the ability of an image receptor to record adjacent small objects as separate and distinct.
    True: when an IR is able to image small objects effectively, it is said to provide increased spatial resolution.
  57. T/F: The lp/mm is the only unit of measurement for spatial resolution.
    False: spatial resolution can also be measured in cycles/mm.
  58. T/F: Pixel size influences the spatial resolution of an image.
    True: the pixel is the smallest part of the digital image. the smaller the pixel is, the higher the resolving power of the IR.
  59. T/F: Increasing the sampling frequency means that more samples are taken per given unit of measurement.
    • True: the sampling frequency determines how small the pixels will appear on the finished image as well as how close these
    • pixels are to each other. increasing the sampling frequency increases the amount of information gathered.
  60. T/F: The greater the sampling frequency, the more information is extracted from the image receptor.
  61. T/F: Current sampling frequencies for PSP image receptors range from 10 pixels/mm to 60 pixels/mm.
    False: sampling frequencies for PSP based image receptors range from 5 pixels/mm up to 20 pixels/mm.
  62. T/F: The range of exposure values that a receptor  responds within is known as dynamic range.
  63. T/F: The wider dynamic range of the digital receptor allows for an equivalent exposure latitude.
    False: dynamic range refers to an image receptor's ability to respond to an exposure; exposure latitude refers to the range of exposures that will create an optimal image.
  64. T/F: The visual appearance of the digitally acquired image is the only way to tell if the exposure settings were accurate.
    False: there are very few visual clues to tellthe radiographer if a digital image is over- or under-exposed. exposure indicators help to identify over- and under-exposures.
  65. T/F: The penumbra is the area of least blur in an image.
    False: penumbra is the area of geometric blur surrounding the edges of the object. the finite size of the focal spot is the cause of penumbra.
  66. T/F: Motion blur is the result of any motion of a tube, body part or film that occurs during the exposure.
    True: motion blur can be caused by themovement of the patient, IR,  or x-ray tube during the exposure.
  67. T/F: The photocathode produces electrons from
    x-ray photons.
    False: remnant radiation that has passed through the patient first strikes the input phosphor of an ii. the input phosphor gives off light photons that strike the photocathode, causing electrons to be released.
  68. T/F: The output phosphor produces light from x-ray photons.
    False: the input phosphor gives off light photons that strike the photocathode, causing electrons to be released. These electrons strike the output phosphor, causing light photons to be emitted.
  69. T/F: The line scan image extraction process is more likely to occur in a cassette-less image extraction PSP system
    • True: the line scan process is more efficient when the plate is held in a fixed position and the reading equipment moves over
    • it.
  70. T/F: All cassettes must be placed into a PSP plate reader in a horizontal orientation.
    False: the vendor's equipment determines how the cassette is placed into the reader. each reader is different.
  71. T/F: The spatial resolution in a flat-panel detector is controlled by the detector element (DEL)
    True: DELs collect the image data in the flat-panel detector and send it to the computer for processing.
  72. T/F: Detector elements are automatically erased after sending their image data for processing. So there's is no need to erase a
    flat-panel detector.
    True: PSP plates, not flat-panel detectors, must be erased after every exposure to remove the electrons that remain.
  73. T/F: Analog films can be digitized even if an imaging department doesn't have digital imaging equipment.
    True: some departments without digital imaging equipment digitize their images to save storage space, for teleradiology, or to prepare for future digital expansion.
  74. T/F: Radiologists shouldn't interpret digitized images due to their poor image quality
    False: actually, the image quality of a digitized image is quite good and radiologists interpret digitized images every day. however, given the choice between a digitized image and the original image, the original image will always display more information.
  75. T/F: One of the benefits of digital imaging is that the software easily compensates for collimation errors.
    False: exposure field recognition errors can occur when collimation borders are not properly used.
  76. T/F: A priori histogram analysis, compares the data collected from a digital image with the histogram of the same body part.
    • True: a priori histogram analysis doesn't compare the data. Instead, a priori histogram analysis consists of three types:
    • Type 1 is an extremity model; Type 2 is a general model; and Type 3 is a metal model.
  77. T/F: In neural histogram analysis the data from a digital image is compared to pre-existing histograms and matched to the one
    it most closely resembles.
    True: the histogram may be matched based on pathology, positioning, or collimation.
  78. T/F: The flat-panel detector determines the edge of a collimated field by how many x-rays strike each DEL.
    False: the flat-panel detector determines the edge of the collimated field based on how many electrons are present in each detector element.
  79. T/F: Automatic rescaling can compensate for minor errors in technical factor selection without affecting the digital image.
    True: automatic rescaling is responsible for digital imaging's ability to respond to a wide range of exposure values.
  80. T/F: "Dose creep" refers to the progressive reduction in dose to patients as technologists rely on automatic rescaling to compensate for underexposure.
    False: dose creep refers to the potential for patient exposures to gradually increase over time due to a lack of visual clues over exposure.
  81. T/F: A poorly recognized exposure field or collimation borders can lead to miscalculating the exposure indicator for a given part.
    True: These are the common causes of exposure indicator miscalculation.
  82. T/F: Selecting the correct processing code menu for the primary part being examined helps assure images display with consistent brightness and contrast.
  83. T/F: Exposure indicators for flat-panel detectors are determined by how much radiation reaches the detector elements or as a result of the histogram analysis.
    True: exposure indicators can be determined by directly measuring the amount of radiation that reaches a detector element (REX and EXI) or the speed class operation (EI).
  84. T/F: DAP meters measure the exposure levels that
    the image receptor receive.
    False: DAP meters measure the exposure levels and the collimator and calculate an entrance skin exposure based on this measurement.
  85. T/F: The DAP readout can be considered a part of a patient's permanent record.
    True: Because the DAP meter measures the entrance skin exposure delivered to the patient, DAP readouts can be considered part of a patient's image record.
  86. T/F: CAD stands for "computer aided diagnosis"
    False: CAD stands for computer aided detection. the CAD system only helps radiologists and the rest of the health care team render a diagnosis.
  87. T/F: CAD systems can be used with both film/screen and digital imaging systems.
    True: images created on radiographic film can be digitized before the image data are sent to the CAD system to analyze.
  88. T/F: A breast tomosynthesis study of one breast exposes a patient to less radiation than a single digital mammogram exposure.
    False: one breast tomosynthesis exam exposes a patient to approximately 50% more radiation than a single digital mammogram exposure. however, a breast tomosynthesis exam may result in the patient needing only one view, which could lower the total exposure.
  89. T/F: Less compression is one benefit of breast tomosynthesis for patients.
    • True: in the breast tomosynthesis exam, compressing tissue to move anatomy out of the way is not as important because
    • the exam visualizes all breast anatomy.
  90. T/F: LCD monitors excel over cathode ray tube displays because they consume less energy and have better spatial resolution
    • True: Lower power consumption and increased spatial resolution are reasons why LCDs are rapidly replacing CRT
    • display monitors
  91. T/F: Technologist workstation LCD monitors have luminance levels similar to analog viewboxes which makes ambient lighting conditions less of a concern?
    False: workstation LCD displays have much lower luminance than traditional viewbox illuminators used to view analog images.
  92. T/F: The contrast capability of a monitor controls the ability of users to see lines and fine structures in a displayed image.
    True: when viewing images on displays with poor contrast capabilities, it's very difficult to see structural lines and fine image details as separate and distinct from background textures.
  93. T/F: The modality work-list information provided by a modality workstation should at a minimum include the modality, examination requested and patient location.
    True: although workstation displays may include many more items, the modality, exam requested, and patient location are considered essential
  94. T/F: Postage stamp images on workstation display monitors help technologists navigate through images of a given exam or series of exams
    False: these images are referred to as thumbnail images, not postage stamp images
  95. T/F: At times a technologist must modify the order that generates the work-list entry. The sender must notify the recipient of this change in the patient’s charted record and explain it, if possible.
    True: the electronic modifying data in a patient record requires the same documentation as traditional paper records.
  96. T/F: Modality workstation software allows a black mask to be placed over bright areas of display images caused by beam collimation. This masking of bright areas is referred to as stitching.
    False: stitching combines two separate images into one image. shuttering is the term used to describe adding black boarders to an image display.
  97. T/F: "Edge Enhancement" describes the manipulation of pixel values in extracted image data to change the visual appearance of a structure.
    True: edge enhancement uses processing codes to sharpen the edges of bone and trabecular patterns.
  98. T/F: If Image A exhibits a lower level of graininess than Image B,  noise suppression can account for this difference in image appearance.
    True: noise suppression, or smoothing, is an image processing technique that reduces noise in an image.
  99. T/F: Electronic annotation, which places an anatomical side marker on an image at the technologist workstation, should not be a common practice even though it's possible.
    True: electronic annotation occurs after the image is taken.
  100. T/F: When exporting an image to print, it's critical that the laser
    camera/printer recognize the image’s actual size format and scale.
    True: laser cameras or printers can print to different sized films or a single size film.
  101. T/F: Of the two types of laser films used to print patient images, dry laser films require only heat for image transfer and are less likely to degrade than wet type laser film when subjected to temperature variations.
    False: dry laser film is more likely to degrade in a storage environment where temperatures are controlled.
  102. T/F: Increased chemical concentration in a film/screen processor can cause increased density on a radiographic film.
    True: increased chemical concentration over-processes the image and increases radiographic density.
  103. T/F: Increased filtration increases radiographic density.
    False: increased filtration results in more attenuation of the primary beam and decreased radiographic density.
  104. T/F: Low kVp causes excessively high radiographic contrast.
    • True: Low kVp weakens the x-ray beam, which causes the body to absorb more x-ray photons and leads to increased
    • contrast.
  105. T/F: The increased scatter that reaches the image receptor also increases contrast.
    False: increased scatter degrades radiographic contrast by decreasing the different densities in an image.
  106. T/F: Motion is the largest contributing factor to blur in radiographic images.
    True: although geometric factors cause blur in images - motion, particularly patient movement, is a major cause of blurring in radiographic images.

  107. T/F:   A decrease in radiation intensity always causes increased image brightness in a digital image.
    True: increased image brightness is almost always the result of a processing error.
  108. T/F: When collimation fields are not recognized, a rescaling error may occur and cause the image to display improperly.
    • True: one way to determine whether the collimation borders have been recognized is to assess the unexposed areas
    • of the image. If they are pure white, then the borders were recognized.

  109. T/F: An image that doesn't display with the correct brightness must be repeated.
    False: sometimes the image can be reprocessed to correct the processing errors and properly display the image. This prevents exposing the patient to additional radiation.
  110. T/F: Geometric factors are the most common reason for image blur.
    False: the major cause of image blur is usually patient motion
  111. T/F: Motion is difficult to see on a technologist's workstation monitor.
    True: motion is often difficult to see on the monitors used by technologists, but easier to see on the radiologists' higher quality monitors. Therefore, technologists should magnify images and examine them for motion before they are sent to be interpreted.
  112. T/F: Everything possible should be done to limit image distortion.
    False: sometimes distortion is necessary in order to see specific anatomy or to project an anatomic structure free of superimposition.
  113. T/F: Noise in a digital image can generally be reduced by increasing the intensity of the x-ray beam.
    True: noise is the result of too little signal reaching the IR. this can usually be improved by increasing the intensity of the x-ray beam.
  114. T/F:  Exposure indicators only change when the intensity received by the image receptor changes.
    False: exposure indicators will also change due to exposure field recognition errors, unexpected structures in the exposure field, and excessive scatter.
  115. T/F: One common artifact occurrence is dirt on the light guide.
    True: dirt on the light guide prevents digital image data from traveling from the PSP to the photomultiplier tube.
  116. T/F: Most artifacts caused by dirt and dust are found in cassetteless rather than cassette-based image receptors.
    • False: cassette-based image receptors are removed for processing and have a better chance of picking up dust and
    • dirt.
  117. T/F: Individual DELs or rows of DELs can be replaced when they fail.
    False: the entire panel must be replaced when a single DEL or a row of DELs fail and produce an artifact on an image.
  118. T/F: Most artifacts appear bright or white on a digital image.
    True: most digital artifacts occur when the signal is prevented from reaching the processing unit.
  119. T/F: PACS transports and stores digital images but doesn't acquire images.
    True: PACS delivers digital images via a network and stores them, after they are read, on a server. They system works with images that are acquired from several other sources.
  120. T/F: PACS eliminates the possibility that images will be lost.
    False: Digital images can be lost on a PACS, even though the system greatly reduces the chance.
  121. T/F: DICOM is a computer program used in digital imaging that converts all files into a common file type.
    • False: DICOM is a standard way to export
    • and import digital image data that vendors have agreed upon. These standards allow images created on one type of equipment to be printed or stored on other vendors' equipment. DICOM compliance has different levels.
  122. T/F: A HIS may contain financial information about a patient.
    True: a hospital information system (HIS) may contain a great deal of information about a patient, including financial information. Only a small part of all the information contained in the HIS may be transferred to the radiology information system (RIS). financial information would not typically be transferred to the RIS.

  123. T/F: A diagnostic workstation typically displays with higher resolution than a clinical workstation.
    True: a diagnostic workstation is used by radiologists to interpret images while technologists use a clinical workstation to check images before pushing them to the diagnostic workstation. diagnostic workstations have matrix sizes of 2048x2560 or larger while clinical workstations usually have matrix sizes smaller than 2048x2560.
  124. T/F: A RAID can store digital images for up to one year.
    True: a RAID can store digital image data from six months to a year. A jukebox is used for storing images for more than a year.
  125. T/F: A wide area network (WAN) runs at a much faster rate than a local area network (LAN).
    False: because of its smaller geographic location, a LAN generally runs much faster than a WAN.
  126.                                                                                                                                                                       T/F: The unique number that identifies every computer on the Internet is called the router number.
    False: the unique number that is used to identify each computer attached to the internet is called the Internet Protocol address, or IP address
  127. T/F: One way to control a security breach into a network is to use a firewall.
    True: firewalls control traffic between a computer network in a trusted environment and a computer in a less secure environment.
  128. T/F:  Viewing software must also be embedded on a CD when PACS copies digital image data for a patient.
    True: the images could not be viewed without the viewing software due to the proprietary nature of the image data.

  129. T/F: Film-based images can be printed from PACS and read like analog images or sent with patients who request copies.
    True: laser printers allow film-based images to be printed from PACS, transported, and viewed much like ordinary analog film.
  130. T/F: The rem is the conventional measurement unit for dose equivalent when measuring radiation.
    True: the rem is an acronym that stands for Radiation Equivalent in Man. the SI equivalent unit is the sievert (Sv) 
  131. T/F: Most of the dose a radiographer receives comes 
    from x-ray tube leakage.
    False: most of the radiation dose a radiographer receives is from scattered radiation patients emit.
  132. T/F: Lead aprons must be a minimum of one mm thick.
    False: lead aprons should be between 0.25 and 0.5 mm lead equivalent in thickness. lead aprons thicker than this would be extremely heavy.
  133. T/F: Shadow shields don't have to touch a patient when used properly.
    True: Shadow shields attach to the collimator and cast a shadow on the patient over where no radiation will be directed.
  134. T/F:  The optimal kVp is the setting that will create the best quality image with the lowest possible patient dose
    • True: the optimal kVp is a balance between quality and patient dose. using high kVp will decrease patient dose, but degrades the image. Using low kVp techniques will increase contrast, but
    • greatly increase patient dose.
  135. T/F: PBL reduces patient dose by automatically reducing the radiation field size.
    True: PBL stands for "positive beam limitation," an acronym that's not very descriptive. it means automatic collimation. this occurs when a cassette is placed in a film tray. this ensures that the radiation field will never be larger than the cassette size.
  136. T/F: Digital imaging algorithms can make a digital image look acceptable no matter what technical factors we use.
    False: although digital imaging processing algorithms can compensate for over- and under-exposure to some extent, severe over- and under-exposure still affects how a digital image displays.
  137. T/F: Changing the visual appearance of a digital image to match the accepted appearance for a given anatomical structure is known as automatic resolution.
    False: adjusting the image data to match the accepted display data for a particular anatomical structure is known as automatic rescaling.
  138. T/F: The primary controller of contrast in digital imaging is kVp.
    False: contrast is primarily controlled by the processing codes used in digital imaging.
  139. T/F: Using kVp to adjust for grid ratio increases in digital imaging is a viable way to adjust technique without affecting image quality.
    • True: increasing kVp to adjust for agrid ratio change is acceptable practice to decrease patient dose without affecting image quality. this is due to the processing codes that define
    • radiographic contrast.
  140. T/F: Image noise limits the speed class of operation.
    True: As the speed class of operation increases, the image noise also increases. a radiologist determines the level of noise that is acceptable, which then determines the speed class of operation.
  141. T/F: The speed class of operation for an analog image receptor is fixed.
    True: the speed class of operationfor an analog IR is based solely on exposure. if the image does not display properly it must be repeated with more or less radiation intensity.
  142. T/F: The image erasure test ensures that a "ghost" image does not remain on an imaging plate after it's erased.
    True: a ghost image is residual image data that remain on a plate from a previous image capture.
  143. T/F: The laser jitter test evaluates the transport system of the PSP plate reader.
    • True: the transport system is evaluated by looking at a phantom image that has been sent through the plate reader. any interruption in the image data perpendicular to the direction of
    • the plate travel may indicate a problem.
  144. T/F: The LCD display monitors exhibit a greater viewing angle than CRT displays.
    False: the CRT exhibits a greater viewing angle.
  145. T/F: The white lines of the SMPTE test pattern are useful detecting a monitor may be a source of image distortion.
  146. T/F: the TG18CX test pattern is an effective tool in evaluating the spatial resolution of a display monitor
  147. T/F: The wire mesh test evaluates image distortion.
    True: the wire mesh is used as in film/screen imaging to identify areas of the IR that may be warped or bent. these areas appear as distorted areas on the digital image.
  148. T/F: Ghost images that appear during an image retention test indicate that a DEL did not reset to a zero reading after an exposure.
    True: when a DEL does not reset to zero following an exposure, a double exposure called a "ghost image" remains on the image.
  149. F: A fine wire mesh screen aids in the detection of stitching artifacts in a flat panel detector.
  150. T/F: Digital fluoroscopy equipment must be evaluated using a phantom that displays life-like human anatomy.
    False: digital fluoroscopy does not use processing codes based on anatomical structures to display the image, so it can be evaluated with a plexiglas phantom.
  151. T/F: Detecting software artifacts on a digital fluoroscopic unit can be done by evaluating a subtraction image with no information to subtract.
  152. T/F: Technologist inspection of cassettes should be included as part of a daily quality assurance routine.
  153. T/F: PSP plates may be erased daily, weekly or monthly depending on the protocols designed by the imaging department
    True: vendors and medical physicists may offer recommendations on how often plates should be erased. but it is up to the imaging department to establish a systematic process for erasing plates.
  154. T/F: The body part should be placed as close to the image receptor as possible to produce the best quality image.
    True: decreasing OID reducesmagnification and improves spatial resolution.
  155. T/F: Radiographers should input patient data such as name and birth date into the RIS in the exam room before an exam begins.
    False: patient data should be inputinto the HIS when the patient registers. in most cases, RIS pulls information from the HIS.
  156. T/F: Techniques set using anatomical programming are average techniques that must be adjusted based on patient size.
    True: techniques set with anatomical programming selectors are based on average techniques set by the vendor. imaging departments may adjust techniques based on their preferences.
  157. T/F: Centering an exam is especially important when only certain portions of the image receptor are used to process
    the image?
    True: the processing codes expect to see certain image data that are missing when the image isn't centered properly. this causes a processing error.
  158. T/F: The physical reference point is only used to ensure that images display properly once they are transmitted to a monitor.
    False: the physical reference point also ensures that the correct area of the IR is used to evaluate the image when only a portion of the image data are used for processing.
  159. T/F: Digital image receptors are less sensitive to scattered and background radiation.
    False: the digital image receptor is much more sensitive to scattered and background radiation. less than 100 microRoentgens will fog the image.
  160. T/F: The size of the image receptor does not affect an image's spatial resolution.
    False: using smaller phosphor plates results in greater spatial resolution.
  161. T/F: Changes in OID can affect the exposure indicator.
    True: anything that affects the amount of scatter that reaches the IR can affect the exposure indicator. increasing OID reduces scatter through a process known as the air-gap technique.

  162. T/F: It is estimated that up to 25% of the energy captured by an exposure plate is lost within eight hours following plate exposure.
  163. T/F: A PSP plate should be erased if it has not been used within the past 48 hours.
    True: most manufacturers recommend erasing plates every 48 hours if the plate has not been used. this removes any scattered or background radiation that the plate might have absorbed.
  164. T/F: Informal learning in the clinical setting is often just-in-time learning designed to complete a task or accomplish some immediate goal.
    True: this is the type of learning many technologists take advantage of in the clinical setting.
  165. T/F: Providing learners with a clue or prompt that lets them know what to expect from the learning event helps them understand what to do with the new information.
    True: this is a very powerful strategy for helping learners to attend to new information.
  166. T/F: Files sizes in digital mammography are larger than file sizes found in general digital imaging.
    True: files sizes in digital mammography range in size from 200-250 megabytes for a four view study. a lumbar spine series in diagnostic radiology is about 40 megabytes in size.
  167. T/F: The DMIST study found that digital mammography is an especially useful option for women with dense tissues.
    True: the DMIST study not only found that digital mammography was a good option for women with dense tissues, butalso for women younger than 50 and women who recently reached menopause.