Image Production: Equipment Operation and Quality Assurance Flashcards
221 - To verify the accuracy of the timer on a three-phase equipment, which exposure timer test is utilized?
A. Wire mesh test
B. Spin top test
C. Synchronous timer test
D. Gramophone motor spindle test
C. Synchronous timer test
A three-phase unit’s timer accuracy can be verified using a synchronous timer. Timer accuracy is measured by measuring the degrees of arch of a density band that is formed on the resulting radiograph, as opposed to measuring individual density dots such as with a spin top test. The exposure duration is computed by dividing the density arch’s degrees by 360 degrees.
222 - In the given image of a tube housing, what does A represent?
A. Tungsten
B. Rotor
C. Stator
D. Cathode
D. Cathode
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
223 - In the given image of a tube housing, what does A represent?
A. Anode
B. Cooling dielectric oil
C. Beryllium tube window
D. Cathode
A. Anode
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
224 - What does the S represent in this image of a tube housing
A. Anode
B. Cathode
D. Induction stator
C. Evacuated tube envelope
D. Induction stator
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
225 - By monitoring the mR/mAs output at various mA and time settings, linearity tests can be conducted. During a linearity test, variation cannot exceed what value?
A. +/- 10%
B. +/- 12%
C. +/- 5%
D. +/- 15%
A. +/- 10%
The ability to identify equipment malfunction is an essential skill required of radiologic technologists. During quality assurance testing, it is vital to evaluate exposure linearity and repeatability to ensure that radiography equipment is functioning properly and to identify possible causes of radiographs which are produced too light or too dark. A linearity test can be performed by observing the mR/mAs output across various mA and time settings. This test allows for a maximum variation of 10%.
- Which Letter in this diagram indicates the source of electrons
B
A
C
T
R
C
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
227 - Which letter in this diagram indicates where x-rays are produced?
R
C
T
S
A
B
T - Anode target
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
228 - Using self-induction, which component of the X-ray circuit regulates and determines the voltage that is transmitted to the high-voltage transformer’s primary winding?
A. Step-up transformer
B. Autotransformer
C. High-tension transformer
D. High-voltage transformer
B. Autotransformer
The voltage applied to the high-voltage transformer’s primary winding is controlled by the autotransformer. It uses the self-induction principle to function. The mutual induction concept governs the operation of the step-up or high-voltage transformer. The purpose of the step-up transformer is to convert low voltage to the high voltage necessary to generate X-ray photons.
229 - What is the purpose of the step-up transformer?
A. Convert high voltage to low voltage
B. Apply low voltage to the transformer’s primary winding
C. Generate protons
D. Convert low voltage to high voltage
D. Convert low voltage to high voltage
The voltage applied to the high-voltage transformer’s primary winding is controlled by the autotransformer. It uses the self-induction principle to function. The mutual induction concept governs the operation of the step-up, or high-voltage transformer. The purpose of the step-up transformer is to convert low voltage to the high voltage necessary to generate x-ray photons
230 - By stopping the exposure when a predefined amount of ionization and image density is reached, which X-ray technology yields consistent radiographic data?
A. Photomultiplier AEC
B. Photocathode AEC
C. Ionization chamber AEC
D. Phototimer AEC
C. Ionization chamber AEC
Radiographic results can be consistently and comparably produced by means of automatic exposure control (AEC) equipment. One kind of AEC involves an ionization chamber situated above the IR and underneath the tabletop. The anatomical part is centered on the sensor and radiographed, enabling the exposure to automatically end when the appropriate density is reached through a predefined level of ionization. A phototimer (photomultiplier), which is a small fluorescent screen, is placed underneath the cassette in an alternative kind of AEC. The fluorescent screen emits light when the residual radiation from the patient exposes the image receptor (IR) and leaves the cassette. The exposure ceases when the photocell sensor detects a specific quantity of fluorescent light.
231 - For what kind of radiographic unit is a spin top test conducted?
A. Three-phase unit
B. Half-wave rectified unit
C. Fully rectified unit
D. A and B
E. Single-phase unit
E. Single-phase unit
For single-phase units, an exposure timer test called a spin top test can be conducted. In the case of a half-wave rectified unit, this test produces a visible number of dots of density equal to the exposure timer setting × 60, and in the case of a completely rectified unit, equal to the exposure timer setting × 120. Any fluctuation in the dots seen on the radiograph suggests a faulty timer or rectifier.
232 - For a radiographic examination, a 72-inch SID is utilized. What is the minimum distance that the radiation field needs to be aligned with respect to the edge of the light field?
A. +/- 1.4 inches
B. +/- 3.6 cm
C. +/- 2 cm
D. +/- 2.1 inches
E. A and B
E. A and B
Accurate beam restriction requires the light field to radiation field alignment to be within plus or minus 2% of the source to image distance (SID). 1.4 inches, or 3.6 cm, is the equivalent to 2% of a 72-inch SID. Positive beam limitation, for example, is one kind of beam restricting device. When employing automatically light-localized variable aperture collimators, the field control must be within 2% of the SID.
233 - The quantity of scatter radiation that reaches the image receptor (IR) rises with kVp. What impact does this have on radiographic contrast?
A. Contrast is unchanged, but quantum mottle results
B. Contrast is unchanged, but density decreases
C. Contrast decreases
D. Contrast increases
C. Contrast decreases
The amount of scatter radiation that reaches the image receptor (IR) increases with an increase in kVp. This causes a decrease in radiographic contrast.
234 - Computed radiography (CR) employs reusable solid-state image receptors (IRs). What is the active ingredient that absorbs X-ray energy and becomes energized?
A. Amorphous selenium
B. Amorphous silicon photodiodes
C. Cesium Iodide scintillation phosphor
D. Europium-activated barium fluorohalide
D. Europium-activated barium fluorohalide
A reusable solid-state image receptor and photostimulable phosphor (PSP) are used in computed radiography (CR), a type of digital radiography. The active ingredient in the cassette-based CR system is europium-activated barium fluorohalide. The PSP’s sensitivity is comparable to that of a 200-speed film/screen system.
235 - Which of the following is an essential component of the CR plate reader?
A. Photomultiplier tube
B. Cesium Iodide scintillation phosphor
C. Thin-film transistor
D. Active matrix array
A. Photomultiplier tube
A reusable solid-state image receptor and photostimulable phosphor (PSP) are used in computed radiography (CR), a type of digital radiography. By subjecting a latent image to a high-intensity laser beam, the CR image is made visible. Trapped electrons in the PSP can return to the valence band when the laser beam releases violet light. An extremely sensitive photomultiplier tube detects violet emission and transforms the light into an electrical signal. The photomultiplier tube’s electrical signal is converted to digital form and saved for later viewing on a computer monitor. The PSP becomes active in response to as little as 10 µR. A PSP should be erased if it is not used for more than 48 hours.
236 - Solid-state detectors are used in the cassette-less direct digital radiography system. Processing can be accomplished in two ways: one method coats an active matrix array of amorphous silicon photodiodes with a cesium iodide scintillation phosphor, while the other method does not. Which technique yields the greatest spatial resolution?
A. The method which involves coating CsI over an AMA of a-Si photodiodes
B. The method in which remnant radiation interacts directly with a-Se
C. Both methods yield the same level of spatial resolution
D. The CsI method offers both enhanced spatial resolution and lower patient dose
B. The method in which remnant radiation interacts directly with a-Se
Solid-state detectors are used in the cassette-less direct digital radiography system. Remnant radiation interacts directly with a thin layer of amorphous selenium (a-Se), producing electron hole pairs (EHP). The thin-film transistors’ (TFTs) active matrix array (AMA) is charged by the EHP signal. Superior spatial resolution is achieved by the phosphor coating-free a-Se processing approach. Comparatively, reduced radiation dosage to the patient and high detective quantum efficiency (DQE) are two advantages of the CsI phosphor method.
237 - Direct digital radiography can be achieved through use of which components?
A. Thin-film transistors
B. Cesium Iodide scintillation phosphors
C. Amorphous silicon photodiodes
D. Amorphous selenium
E. All of the above
E. All of the above
The cassetteless direct digital radiography system uses solid-state detectors. There are two approaches to processing: the first applies a cesium iodide scintillation phosphor to an active matrix array of amorphous silicon photodiodes, whilst the second approach does not. Remnant radiation directly interacts with a thin layer of amorphous selenium (a-Se) in the approach that does not make use of the phosphor coating, creating electron hole pairs (EHP). The EHP signal charges the active matrix array (AMA) of thin-film transistors (TFTs). The a-Se processing method without phosphor coating can yield better spatial resolution. In contrast, the CsI phosphor technique offers two advantages: a lower radiation exposure to the patient and a higher detective quantum efficiency (DQE).
238 - The ability to modify a digital image’s brightness and contrast is achieved through which of the following?
A. Networking
B. Leveling
C. Rescaling
D. Windowing
D. Windowing
The capability to modify a digital image’s contrast and/or brightness is known as windowing. Digital systems with automatic rescaling can generate images with a consistent brightness display throughout a broad exposure range.
239 - What impact does SID have on radiographic density?
A. SID is unrelated to density, and inversely related to contrast
B. As SID decreases, density decreases
C. SID is unrelated to density, and directly related to contrast
D. As SID increases, density decreases
D. As SID increases, density decreases
There is an inverse relationship between SID and radiographic density. Density decreases with increasing SID. The amount that density varies as SID is changed is determined by the inverse square law. If SID is altered, the change in mAs needed to produce an image with a similar density is determined by the direct square law.
240 - What technical parameter influences tissue attenuation, radiographic contrast, and beam penetrability?
A. mAs
B. OID
C. S-number
D. kVp
E. A, B, and C
D. kVp
Raising kVp makes the x-ray beam more penetrating, but tissue attenuation capacity falls and radiographic contrast is reduced.
241 - What percentage of kVp modification is necessary to achieve an appreciable alteration in density within the radiographic image?
A. 25%
B. 20%
C. 15%
D. 10%
C. 15%
A kVp modification of at least 15% is required in order to produce an appreciable change in density within the radiography image. Generally, if a radiograph must be reacquired because of overexposure or underexposure, the exposure variables used to produce the original radiograph should be doubled or halved.
242 - Which stage of image processing involves the conversion of an analog signal to a digital value?
A. Developing
B. Acquisition
C. Archiving
D. Data manipulation
B. Acquisition
The process of obtaining and recreating an image on a digital platform is known as image acquisition. It entails the methodical application of extremely intricate mathematical concepts and computations known as algorithms. Analog signals, or electrical pulses, are transformed to digital values throughout the image acquisition process.
243 - The reciprocity law formula states that density rises or falls in proportion to:
A. kVp
B. SID
C. mAs
D. Film-screen speed
C. mAs
Density is one aspect influencing image evaluation. Density follows the reciprocity rule formula, increasing and decreasing proportionately with mAs.
244 - What percentage of mAs modification is necessary to achieve a noticeable change in density within the radiographic image?
A. 50%
B. 10%
C. 15%
D. 30%
D. 30%
A mAs modification of at least 30% is required in order to produce an appreciable change in density within the radiography image. Generally, if a radiograph must be reacquired because of overexposure or underexposure, the exposure variables used to produce the original radiograph should be doubled or halved.
245 - To what component of the fluoroscopic image is fluoroscopic mA directly related?
A. Saturation
B. Contrast
C. Spatial resolution
D. Brightness
D. Brightness
The fluoroscopic image’s brightness has a direct correlation with fluoroscopic mA. A thicker anatomical part imaged during a fluoroscopic examination will appear dimmer when all other imaging variables remain unchanged. A photocell at the image intensification tube’s output phosphor end measures light intensity. Electronically, video signal strength readings are compared to reference values. The automatic brightness control (ABC) function will modify fluoroscopic mA to help keep the brightness and video signal strength within a suitable range if the light intensity and strength drop below predetermined values.
246 - A dead pixel is inherent to which of the following devices?
A. Flat panel detector
B. Image receptor
C. Detector element
D. Display device
D. Display device
Whereas a dead pixel is inherent to the display device, a dead dexel is inherent to the detector. When a radiographic image is displayed, an intrinsic artifact caused by a dead dexel, also known as a detector element, will be visible. A dead pixel is one that is not present in the radiographic image and vanishes when the viewing medium is altered. Distinguishing between a defective pixel and dexel is straightforward since the former always remains the same relative size and placement on the viewing screen (display device) while the latter remains in the same location and size on the image.
247 - Which grid error appears as total cutoff toward each end of a radiographic image, with a normal density toward the center?
A. An upside-down grid
B. Lateral deviation of the central ray to a focused grid
C. Grid use outside of the specified focal range
D. A reciprocating grid which fails to move mid-exposure
A. An upside-down grid
An upside-down grid will appear as total cutoff toward each end of a radiographic image, with a normal density toward the center. This occurs because focused grids are designed with lead strips that angle progressively outward to match the divergence of the X-ray beam. When placed upside down, the angling of the lead strips is reversed, leading to severe cutoff at the image periphery while maintaining normal density at the center.
248 - A step-down transformer is also called a:
A. Low voltage transformer
B. Filament transformer
C. High tension transformer
D. High voltage transformer
E. A and B
E. A and B
Another name for a step-down transformer is a filament, or low voltage transformer. It uses two wires and works on the electromagnetic mutual induction principle. This transformer modifies the voltage and current delivered to the radiographic tube’s filament. 8 to 12 volts is the voltage range that is transmitted to the filament within the radiographic tube from the secondary side of the filament transformer. High tension or high voltage transformers are other names for step-up transformers. The x-ray circuitry is divided into sections including primary (low voltage) or secondary (high voltage) segments. The principle of electromagnetic mutual induction also governs the step-up transformer’s operation. Current decreases at a rate equal to the turns ratio while voltage increases.
249 - Which of the following describes the application of the digital image processing technology histogram equalization?
A. Contrast enhancement
B. Dimming correction
C. Density alteration
D. Edge enhancement
A. Contrast enhancement
One method for enhancing contrast in digital images is called histogram equalization. Histogram equalization is one of the primary digital image processing techniques used in image windowing. This method is frequently required when the collected data is localized within a small range of values, as this would lead to a poorly optimized usage of the entire display’s spectrum.
250 - Which of these describes a post-processing technique?
A. Image stitching
B. Edge enhancement
C. Windowing
D. Collimating
E. A, B, and C
E. A, B, and C
Through postprocessing, the radiographer using CR or DR equipment can alter the digital image that is apparent on the cathode ray tube (CRT). Image stitching, picture inversion, windowing, image reversal, edge enhancement, and image rotation are examples of postprocessing techniques. Through windowing, one can change the width or level of the window to control the brightness and contrast of the image. Image brightness fluctuates with window level adjustments, but the number of gray shades, or contrast resolution/contrast scale, varies with window width.
251 - Which test can identify regions where there is inadequate film-screen contact?
A. Wire mesh test
B. Precision photometer test
C. Light-beam alignment test
D. Half-value layer test
A. Wire mesh test
The wire mesh test is one test that can be conducted to identify areas where there is insufficient film-screen contact. In locations where there is inadequate contact between the film and the screen, the radiograph’s recorded detail decreases and appears as blurred regions on the film.
252 - In radiography, how is an overexposed or underexposed image corrected following the assignment of values of interest (VOIs)?
A. Adjusting mAs
B. Exposure histogram recognition
C. Rescaling
D. Window height modification
C. Rescaling
In digital systems, a dataset is created by the computer into a histogram. The exposure that each pixel element receives and the frequency of those exposures within the image are graphed together to form the histogram. This produced histogram is contrasted with a model of the stored histogram for the anatomical region of interest (ROI); VOIs are found, and the image is displayed. In order to keep the image brightness constant even when the image receptor (IR) is overexposed or underexposed, histogram analysis is also used. We call this process automatic rescaling. Even in cases where the exposure is excessively high or low, automatic rescaling, a feature of image processing software, will provide an image at the proper predetermined brightness level.
To offer a certain brightness display, the computer rescales the image depending on the comparison of the histograms, which is essentially a grayscale to VOI mapping operation. Wide latitude and automatic optimization of the values of interest (VOI) in the radiologic image are provided by exposure data recognition (EDR) and automatic rescaling. The chosen processing algorithm and its LUT, when combined with EDR, provide correction for under- and overexposure. While using the rescaling feature, radiographers must be conscious of their duty to minimize patient dose. Underexposure leads to lower image quality due to increased image noise, while overexposure, although digitally correctable, increases patient dosage.
253 - In digital imaging, which of the following is a suitable technique for altering brightness and contrast levels?
A. Look-up table adjustment
B. Utilizing automatic exposure control
C. Altering source-to-image receptor distance
D. Modifying milliampere-seconds
A. Look-up table adjustment
Without a modification in the selected radiographic technique, look-up table (LUT) adjustment can be used to improve the quality of digital radiographs that are under- or overexposed. To enhance the displayed radiographic image’s brightness and contrast, LUTs offer the ability to modify the original pixel values. That is, image-display software allows radiographic LUTs to be dynamically adjusted by window, level, brightness, and contrast.
254 - Which postprocessing modification allows for the adjustment of image density?
A. Window height
B. Window width
C. Window level
D. Windowing
C. Window level
Through postprocessing, the radiographer can alter and improve the digital image that is displayed on the monitor. Windowing is one method of adjusting image brightness and contrast. Windowing describes any modification to the window width or level, which is a LUT modification. Image contrast, or the quantity of gray shades, is affected by changes in window width. Variations in window level have an impact on image brightness or density. While windowing would be an appropriate answer, window level is the best answer because this specifically describes the alteration to image brightness (density).
255 - What kind of postprocessing adjustment can be applied to change the contrast of an image?
A. Window height
B. Window width
C. Altering mAs
D. Window level
B. Window width
Through postprocessing, the radiographer can alter and improve the digital image that is displayed on the monitor. Windowing is one method of adjusting image brightness and contrast. Windowing describes any modification to the window width or level, which is a LUT modification. Image contrast, or the quantity of gray shades, is affected by changes in window width. Variations in window level have an impact on image brightness or density.
256 - Which function can remedy misregistration?
A. Edge enhancement
B. Pixel shift
C. Windowing
D. Image minification
B. Pixel shift
Misregistration transpires when movement of an anatomical part occurs during serial picture acquisition, which prevents precise superimposition. One feature that can rectify misregistration is pixel shift. The determination of the numerical pixel value for a certain ROI (region of interest) is another newly developed postprocessing function utilized in diagnostic imaging.
257 - What postprocessing feature shields the eyes of the radiologist from excess light from the illuminator?
A. Electronic masking
B. Electronic cropping
C. Use of a collimator
D. Applying a cylinder or cone
E. A and B
E. A and B
When a digital radiographic image is acquired and postprocessed, electronic masking—also referred to as electronic cropping or electronic collimation—is a controlled reduction of the displayed data. The size of the irradiated field is not changed by postprocessing adjustment, in contrast to the use of a collimator, cylinder, or cone.
258 - Which of the following radiographic examinations may require image stitching technology?
A. AP femur
B. Scoliosis series
C. Skeletal survey
D. Small bowel follow through
B. Scoliosis series
A single scoliosis radiograph can be created by stitching together two digital radiographs when the field of view is too broad for a single radiographic projection. Stitching is the postprocessing function of taking sequential high-resolution X-ray images of an anatomic part—in this case, the spine—and then integrating them into a single image.
259 - Which of the following makes use of parameters to adjust the amount of contrast, density variance, and steepness of the exposure gradient?
A. Look-up table
B. Contrast enhancement
C. Exposure data recognition
D. Edge enhancement
B. Contrast enhancement
A feature known as contrast enhancement makes use of parameters to adjust the degree of contrast, density variance, and steepness of the exposure gradient.
260 - To improve the detection of fractures in the radiographic image, which of the following sets a pixel count restriction in a neighborhood of the matrix?
A. Windowing
B. Luminance value histogram
C. Dynamic range
D. Edge enhancement
D. Edge enhancement
The quantity of pixels in a matrix neighborhood is restricted by edge enhancement and a higher level of enhancement is obtained with smaller neighborhood sizes. This helps with applications like radiographic image-based fracture and small, high-contrast tissue detection.
261 - Which postprocessing function can compensate for an inappropriately selected kVp or mAs?
A. Appropriate kVp and mAs are essential and cannot be substituted
B. Window level
C. Pixel shift
D. Exposure data recognition
E. Window width
A. Appropriate kVp and mAs are essential and cannot be substituted
A loss of diagnostic information due to inadequate photons, penetration, or overpenetration cannot be recovered or remedied by postprocessing alteration of image parameters.
262 - The monitoring of imaging and radiological operations is made possible using which of the following?
A. EMR
B. EHR
C. HIS
D. RIS
D. RIS
A picture archival and communication system, or PACS, can be linked with RIS (Radiology Information Systems) and HIS (Hospital Information Systems) to store electronic health data. HIS is used to handle medical records and information electronically, as well as to guarantee data availability and security. A system for monitoring imaging and radiological procedures is called RIS. Radiology workflow management, patient scheduling and registration, reporting, patient data distribution and tracking, and billing are all performed using RIS. RIS is essential to the efficient operation of radiologic facilities and works in tandem with HIS.
263 - What is the term for the act of sending and receiving diagnostic medical images remotely?
A. Networking
B. PACS
C. DICOM
D. Teleradiology
D. Teleradiology
Image transmission and viewing via a remote connection is known as teleradiology. A picture archival and communication system, or PACS, allows users to view diagnostic medical images on a display system (i.e., CRT, video workstation). Diagnostic medical imaging procedures can be stored, transmitted, altered, and archived electronically and digitally with the use of a PACS. Digital imaging and communication in medicine (DICOM) enables a common imaging and interface format, and a computer’s capacity to communicate with other computers is termed networking.
264 - Which of the following can be used to evaluate the size of the focal spot and how it affects the radiographic detail that is recorded?
A. Pinhole camera
B. Star pattern
C. Slit camera
D. Radiopaque object (i.e., coin)
E. A, B, and C
E. A, B, and C
In terms of positioning precision, exposure variables, and equipment performance, radiographic results should be reliable and consistent. As part of a continuous quality assurance (QA) program, X-ray equipment should be regularly inspected and calibrated. With a slit camera, pinhole camera, or star pattern, the focal spot can be examined on a regular basis to assess its size and how it affects recorded detail on a radiographic image. A radiopaque object, like a paper clip or a coin, can be placed in each corner of the light field prior to the test exposure in order to verify that the X-ray and light fields are congruent. The radiopaque objects should precisely indicate the corners of the x-ray field after processing.
265 - Periodic testing and calibration of X-ray equipment is an essential component of a continuous quality assurance (QA) program. Which test requires that, prior to a test exposure, a radiopaque object—such as a coin—be placed at each corner of the light field?
A. Focal spot size assessment
B. Light and X-ray field congruence assessment
C. Parallel-line type resolution test
D. Focal length test
B. Light and X-ray field congruence assessment
In terms of positioning precision, exposure variables, and equipment performance, radiographic results should be reliable and consistent. As part of a continuous quality assurance (QA) program, X-ray equipment should be regularly inspected and calibrated. With a slit camera, pinhole camera, or star pattern, the focal spot can be examined on a regular basis to assess its size and how it affects recorded detail on a radiographic image. A radiopaque object, like a paper clip or a coin, can be placed in each corner of the light field prior to the test exposure in order to verify that the X-ray and light fields are congruent. The radiopaque objects should precisely indicate the corners of the x-ray field after processing.
266 - With what kind of apparatus is the uniformity and luminance of image display monitors measured?
A. Chamber survey meter
B. Microplate counter
C. Photometer
D. Radiometric detector
C. Photometer
Both luminance and illuminance, or the quantity of light emanating from a surface and falling on it, can be measured with a photometer. Illuminance is measured in lux (lumens per m²), while luminance is measured in the unit of “nit” (candela per m²). To ensure that collimator light sources comply with requirements, a photometer is utilized. Additionally, it checks an X-ray viewbox for proper brightness and homogeneity by measuring its brightness and uniformity.
267 - Which of the following approaches is appropriate for conducting a sufficient quality control (QC) evaluation of shielding accessories, such as lead aprons?
A. Annual shield thickness measurement
B. Fluoroscopic imaging of shielding devices
C. Physical palpation of shielding accessories
D. Visual inspection of shielding devices
B. Fluoroscopic imaging of shielding devices
The medical physics department of a hospital or the radiation safety office of an organization inspects radiation shields. According to clinical procedure, fluoroscopic imaging should be used at least once a year to evaluate the structural integrity of protective diagnostic imaging shields. Tests are conducted to ascertain the shield’s attenuation properties and the overall area of defects.
