Modules 1-11

• 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.

 

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.

False: Doubling your distance from a radiation source would reduce your radiation exposure to 1/4 of your original exposure.

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.

• True: Reducing field size will reduce the amount of raw radiation striking the IR. This will reduce the effects of
• undercutting.

False: Although grids reduce the amount of scattered radiation reaching the IR, they do not reduce the production of scattered radiation.

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.

• 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.

• 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.

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.

 

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.

 

• 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.

True: x-rays are found on the electromagnetic spectrum and travel in waves much like light photons.

True: When an x-ray photon knocks and inner shell electron out of orbit, photoelectric absorption would occur.

• False: Pleural effusion occurs when fluid fills the pleural cavity where the lungs sit. Therefore, this is an additive
• pathologic condition.

True: Fat and muscle tissue both produce scatter radiation when struck by the primary beam.

 

True: A high SNR means that more of the x-ray beam reaches the IR, compared to undesirable scatter radiation.

 

• 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.

 

True: The emulsion layer of radiographic film is responsible for capturing patient information.

False: the term "latent image" is associated with the invisible image present on the film after exposure.

True: the phosphor layer of the intensifying screen interacts with x-rays to produce light that exposes the radiographic film.

False: the recirculation system filters the operating developer solution.

True: the film transport system entrance rollers interface with a microswitch that triggers processor chemical replenishment.

False: Guide shoe plates are also found in crossover rack assemblies.

False: The acidifier is an essential component of the Fixer solution.

True: This is the function of the clearing agent in the fixer 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.

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.

False: pick-off occurs on dual-emulsion films, it's just not as apparent as pick-off on single-emulsion films.

True: Daily monitoring is essential because slight changes in developer temperature severely affect the opacities of processed film images

False: The daily mid-step density should be measured using the same step.

True.

False: Extended exposure to safelightillumination fogs radiographic film.

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.

 

True: a matrix is made up of all the pixels in a digital image arranged in rows and columns.

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.

True: calcium tungstate, non-calcium tungstate, and rare earth are three phosphor types used in intensifying screens today.

True.

• 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.

True: Silver halide crystals are suspended in gelatin. this allows the processing chemicals to interact with the silver halide crystals more efficiently.

False.

detective quantum efficiency

speed class

True: the photostimulable phosphor is a storage phosphor.

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.

thin film transistor (TFT)

True: detector elements (DELs) are the portion of the TFT that collects electrons and produces an individual pixel.

True: individual DELs contain charges (number of electrons) proportional to the x-rays that strike each one.

True: the CCD is another form of direct image capture that differs from PSP or FPD technology.

True: the CCD uses a scintillator to produce light photons.

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.

True: gas-filled detectors have smaller acceptance angles, meaning they are less sensitive to radiation than scintillator-based detectors.

True: the tightly collimated x-ray beam in CT decreases scatter, which increases image contrast.

• 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.

True.

True: when an IR is able to image small objects effectively, it is said to provide increased spatial resolution.

False: spatial resolution can also be measured in cycles/mm.

True: the pixel is the smallest part of the digital image. the smaller the pixel is, the higher the resolving power of the IR.

• 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.

True.

False: sampling frequencies for PSP based image receptors range from 5 pixels/mm up to 20 pixels/mm.

True.

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.

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.

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.

True: motion blur can be caused by themovement of the patient, IR,  or x-ray tube during the exposure.

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.

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.

• True: the line scan process is more efficient when the plate is held in a fixed position and the reading equipment moves over
• it.

False: the vendor's equipment determines how the cassette is placed into the reader. each reader is different.

True: DELs collect the image data in the flat-panel detector and send it to the computer for processing.

True: PSP plates, not flat-panel detectors, must be erased after every exposure to remove the electrons that remain.

True: some departments without digital imaging equipment digitize their images to save storage space, for teleradiology, or to prepare for future digital expansion.

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.

False: exposure field recognition errors can occur when collimation borders are not properly used.

• 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.

True: the histogram may be matched based on pathology, positioning, or collimation.

False: the flat-panel detector determines the edge of the collimated field based on how many electrons are present in each detector element.

True: automatic rescaling is responsible for digital imaging's ability to respond to a wide range of exposure values.

False: dose creep refers to the potential for patient exposures to gradually increase over time due to a lack of visual clues over exposure.

True: These are the common causes of exposure indicator miscalculation.

True.

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).

False: DAP meters measure the exposure levels and the collimator and calculate an entrance skin exposure based on this measurement.

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.

False: CAD stands for computer aided detection. the CAD system only helps radiologists and the rest of the health care team render a diagnosis.

True: images created on radiographic film can be digitized before the image data are sent to the CAD system to analyze.

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.

• 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.

• True: Lower power consumption and increased spatial resolution are reasons why LCDs are rapidly replacing CRT
• display monitors

False: workstation LCD displays have much lower luminance than traditional viewbox illuminators used to view analog images.

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.

True: although workstation displays may include many more items, the modality, exam requested, and patient location are considered essential

False: these images are referred to as thumbnail images, not postage stamp images

True: the electronic modifying data in a patient record requires the same documentation as traditional paper records.

False: stitching combines two separate images into one image. shuttering is the term used to describe adding black boarders to an image display.

True: edge enhancement uses processing codes to sharpen the edges of bone and trabecular patterns.

True: noise suppression, or smoothing, is an image processing technique that reduces noise in an image.

True: electronic annotation occurs after the image is taken.

True: laser cameras or printers can print to different sized films or a single size film.

False: dry laser film is more likely to degrade in a storage environment where temperatures are controlled.

True: increased chemical concentration over-processes the image and increases radiographic density.

False: increased filtration results in more attenuation of the primary beam and decreased radiographic density.

• True: Low kVp weakens the x-ray beam, which causes the body to absorb more x-ray photons and leads to increased
• contrast.

False: increased scatter degrades radiographic contrast by decreasing the different densities in an image.

True: although geometric factors cause blur in images - motion, particularly patient movement, is a major cause of blurring in radiographic images.

 

True: increased image brightness is almost always the result of a processing error.

• 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.

 

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.

False: the major cause of image blur is usually patient motion

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.

False: sometimes distortion is necessary in order to see specific anatomy or to project an anatomic structure free of superimposition.

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.

False: exposure indicators will also change due to exposure field recognition errors, unexpected structures in the exposure field, and excessive scatter.

True: dirt on the light guide prevents digital image data from traveling from the PSP to the photomultiplier tube.

• False: cassette-based image receptors are removed for processing and have a better chance of picking up dust and
• dirt.

False: the entire panel must be replaced when a single DEL or a row of DELs fail and produce an artifact on an image.

True: most digital artifacts occur when the signal is prevented from reaching the processing unit.

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.

False: Digital images can be lost on a PACS, even though the system greatly reduces the chance.

• 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.

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.

 

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.

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.

False: because of its smaller geographic location, a LAN generally runs much faster than a WAN.

False: the unique number that is used to identify each computer attached to the internet is called the Internet Protocol address, or IP address

True: firewalls control traffic between a computer network in a trusted environment and a computer in a less secure environment.

True: the images could not be viewed without the viewing software due to the proprietary nature of the image data.

 

True: laser printers allow film-based images to be printed from PACS, transported, and viewed much like ordinary analog film.

True: the rem is an acronym that stands for Radiation Equivalent in Man. the SI equivalent unit is the sievert (Sv) 

False: most of the radiation dose a radiographer receives is from scattered radiation patients emit.

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.

True: Shadow shields attach to the collimator and cast a shadow on the patient over where no radiation will be directed.

• 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.

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.

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.

False: adjusting the image data to match the accepted display data for a particular anatomical structure is known as automatic rescaling.

False: contrast is primarily controlled by the processing codes used in digital imaging.

• 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.

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.

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.

True: a ghost image is residual image data that remain on a plate from a previous image capture.

• 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.

False: the CRT exhibits a greater viewing angle.

True.

True.

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.

True: when a DEL does not reset to zero following an exposure, a double exposure called a "ghost image" remains on the image.

True.

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.

True.

True.

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.

True: decreasing OID reducesmagnification and improves spatial resolution.

False: patient data should be inputinto the HIS when the patient registers. in most cases, RIS pulls information from the HIS.

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.

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.

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.

False: the digital image receptor is much more sensitive to scattered and background radiation. less than 100 microRoentgens will fog the image.

False: using smaller phosphor plates results in greater spatial resolution.

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.

 

True.

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.

True: this is the type of learning many technologists take advantage of in the clinical setting.

True: this is a very powerful strategy for helping learners to attend to new information.

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.

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.