Image Acqusition and QA Flashcards
What is the most likely reason for blurring of the glenoid cavity in a technically adequate digital shoulder X-ray?
Patient motion
How does the use of a grid in digital radiography influence the selection of exposure parameters from the technique chart?
Requires higher mAs settings to compensate for the grid’s absorption
Which factor is critical to maintaining high DQE in digital radiography systems?
Regular calibration of the system
What impact does the use of a digital detector with a high DQE have on patient radiation dose during imaging?
Reduce the dose
Which of the following technical factors is the controlling factor for image receptor (IR) exposure?
Milliampere-seconds (mAs)
In a digital radiography, what is the primary consequence of using an excessively high mA setting for an extremity exam?
Overexposure and potential image saturation
What is the most likely result of a gross exposure error due to excessive radiation dose in a pediatric abdominal radiograph?
Increased risk of harm
During a pelvis radiograph, how might incorrect AEC cell selection affect the outcome?
It could lead to overexposure or underexposure
How is a gross overexposure error demonstrated in a digital image?
Missing data points
In situations where a prosthetic device is present, which two options would a radiologic technologist have when using AEC?
- Disable AEC and manually set exposure parameters
- Avoid positioning the device directly over the AEC detectors
Which two of the following are ways a radiologic technologist could adjust the AEC settings for pediatric patients to avoid overexposure?
- Increase the sensitivity of the AEC detectors
- Utillize a lower-energy x-ray beam
How does the application of a low-pass filter impact the appearance of a digital radiographic image?
Reduce image noise
In digital imaging, what is the result of using a higher bit depth?
Increased contrast resolution (more shades of gray)
What equipment error is the most likely cause of the inconsistent brightness seen in the image?
Faulty detector calibration
What is the effect of doubling the distance between the x-ray source and the image receptor on the quality of the digital image if IR exposure is maintained?
Increased spatial resolution
What would be the expected effect on the exposure indicator if a technologist accidentally uses a grid for a pediatric patient where none was indicated without changing technical factors?
The exposure indicator would display lower than usual values
Why is it crucial to use identification markers correctly in a chest radiograph?
To communicate patient orientation
When reviewing SNR values on a detector dose graph, what would indicate an optimal setting for achieving a balance between dose efficiency and image quality?
Highest SNR at the lowest dose
How does utilizing the anode heel effect influence the image quality of a thicker body part?
Improves image uniformity
What is the best practice when using AEC for a PA chest radiograph on a patient with kyphosis?
Adjust the placement of AEC detectors to better align with the anatomical changes
A radiograph with few shades of gray exhibits: (more black and white)
High contrast
How does decreasing pixel size influence the image quality in digital radiography?
Increases spatial resolution and image detail
What is the correct procedure when using AEC for an obese patient?
Adjust the AEC sensitivity to account for increased tissue density
Which of the following changes to AEC settings would be most appropriate when imaging a patient with ascites (fluid)?
Decrease the sensitivity of the AEC detectors
What is the consequence of the AEC detectors being too peripheral during a lateral chest x-ray?
Underexposure
What would be the best approach to configure the AEC for a patient undergoing a chest x-ray who has a pneumothorax?
Decrease the sensitivity of the affected side’s AEC detectors
Which method best evaluates the adequacy of the collimation on a radiographic image of the abdomen?
Measuring the exposure field to ensure it matches the ROI (region of interest)
Source to image distance (SID) refers to the distance from the:
Actual focal spot to the image receptor
When using a digital radiography system, why is it important to follow technique charts when setting exposure parameters?
To ensure consistent image quality and patient dose
How does the orientation of the x-ray beam relative to the anatomical part and the image receptor influence distortion in radiographic imaging?
Perpendicular orientation minimizes distortion
In the processing of digital image acquisition, what is the significance of the initial digital signal conversion step in maintaining image quality?
It enables further processing by the computer
A technologist observes that a skull radiograph has high noise levels. What adjustment during image acquisition or processing is most effective for reducing noise while preserving image detail?
Increasing mAs
To double image receptor exposure, what new KVP is required?
You need to double the KVP
What does the fill factor of a direct digital radiography receptor refer to?
Sensitive portion of the DEL compared to the non-sensitive portion
How should a radiologic technologist adjust the exposure parameters when imaging the patient with osteoporsis (less dense bones) using digital radiography?
Decrease KVP to avoid overexposure
What is the source of radiation in the x-ray tube?
Actual focal spot
What consideration should be taken when selecting exposure parameters for a digital radiograph of an elderly patient with kyphosis?
Increase kVp to penetrate the spinal curvature
Which two of the following factors can affect image receptor exposure?
- mAs
- SID
How does the principle of ALARA influence the frequency of diagnostic imaging tests?
Supports the use of alternative diagnostic methods that do not involve ionizing radiation
Secondary lead barriers are used in radiology departments to:
Protect staff from scatter radiation during radiographic exams
When using a grid to improve image quality, what factor must be adjusted to compensate for the increased attenuation of the x-ray beam?
mAs
Which of the following controls the quality of an x-ray beam?
kVp
In radiography, how does the AEC system adjust when imaging thicker body parts?
Increases exposure time
Which of the following describes the effect of beam filtration on the x-ray spectrum?
It increases the average energy of the beam
What is the effect of increasing the compression of digital image files on the image quality?
Reduction in image detail
What is the primary function of an x-ray tube’s anode?
To serve as a target surface for electron interaction
Which of the following is needed to move electrons through a circuit?
Volts (Voltage)
For a facility updating their radiographic suite, why is it essential to choose display monitors certified for medical use over standard commercial displays?
They offer higher luminance standards for accurate image interpretation
How does altering the window width influence the diagnostic quality of radiographic images in the data for display stage?
By modifying the range of contrast displayed
In digital radiography, how is the uniformity test performed and what does it assess?
By imaging a homogenous phantom to evaluate consistency across the detector
In the context of imaging informatics, which of the following best describes the role of corrected data during image processing?
Enhancement of raw data for clearer visulization
How does the implementation of a standardized noise reduction algorithm affect image quality in digital radiography?
It enhances image clarity by reducing random variations in pixel values
What is the objective of testing the reproducibility of kilovoltage (kV) across different exposures in a radiography system?
To ensure the system accurately replicates the set kV
Which accessory is specifically designed to enhance contrast and reduce scatter radiation reaching the IR in radiography?
Grid
In a high-volume clinical setting, why is it critical to regularly calibrate radiographic imaging displays?
To maintain image consistency and diagnostic reliability
Flux gain defines:
The number of light photons are produced by each electron
What role does the use of a phantom play in the quality control of imaging department?
It evaluates image quality and system accuracy
Which feature of display monitors affects the ability to differentiate between small contrast differences in radiographic images?
Luminance
Which of the following will decrease the size of the effective focal spot?
Decrease target angle
In digital radiography, what is the effect of an increased bit depth?
More shades of gray available
A radiologic technologist is reviewing a digital radiograph and notices that the image appears overly smooth, lacking the expected detail and sharpness. What image processing technique might have been over-applied?
Noise reduction (low-pass filtering)
What is the primary purpose of the oil surrounding the x-ray tube in a radiographic unit?
To serve as a cooling medium
What is the significance of SNR in digital radiography, and how is it measured?
SNR assesses the clarity of the image, measured by comparing the signal intensity to background noise
What are two main disadvantages of a distributed MIMPS?
- There is a heavy reliance on the assumption that the distribution of images is being done correctly
- it is possible for two radiologist to be reading the exam at the same time without knowing
Which of the following materials is essential to latent image production in computed radiography (CR) imaging systems?
Photostimulable phosphor (PSP)
In radiographic imaging, what role does the collimator play?
It configures the x-ray beam to match the area of interest
What aspect of radiographic quality does the MTF test assess?
The system’s ability to preserve image detail at different spatial frequencies
Which of the following components allows for the production of a high-voltage electrical current in the x-ray tube?
Transformers
What is the role of the image processing software in a digital radiography system?
To convert raw data from the digital detector into viewable images
What role does an image histogram play in the quality control of digital radiography systems?
It provides a graphical representation of pixel intensity distribution
When operating a fixed radiographic unit, what role does the Bucky assembly play in image formation?
It holds the image receptor and moves the grid
Why is it important to regularly conduct a geometric distortion test in radiography?
To ensure accurate dimension representations
A radiographer is using a direct DR system. Which factor has the most significant impact on image resolution?
Detector element (DEL) size
What primary advantage does the use of a high-frequency x-ray generator provide over conventional generators in radiographic imaging?
Reduced patient dose
Which of the following devices is an alternative to a photomultiplier tube (PMT) in a computed radiography (CR) plate reader?
Charge-coupled device (CCD)
Why is it important to regularly test the accuracy of the radiographic timer?
To ensure optimal exposure and reduce patient dose
What is evaluated in the ghosting test for digital radiographic systems?
The persistence of a residual image on the detector
The transformer core is typically composed of:
Iron (ferromagnetic increases the strength of the magnetic field)
What is brightness in radiographic imaging?
The amount of luminance of a display monitor
When comparing fixed and mobile radiographic units, which component is typically unique to mobile units to enhance their versatility?
Battery-operated power supplies
In the construction of a radiographic grid, what defines the grid ratio?
Height of lead strips compared to the distance between them
What is the primary function of the automatic exposure control (AEC) in a radiographic unit?
To determine the optimal exposure time
How does the adjustment of window width and window level settings on a radiographic monitor affect image interpretation?
It changes the image display, enhancing the visibility of structures
Which two of these components can collect and covert light into an electrical signal for image production?
- Charge-coupled device (CCD)
- Photodiode
What is the primary purpose of automatic rescaling in digital radiography?
To standardize image brightness and contrast
Which of the following best describes the role of a high-voltage cable in radiographic equipment?
To transfer electricity from the generator to the tube
Which of the following devices allows the free flow of electrons?
Conductor
The image information stored in a computed radiography (CR) imaging plate prior to processing is called the:
latent image
What is the primary purpose of post-processing techniques in digital radiography?
To enhance image contrast and detail after initial processing
How is the beam alignment test conducted in a radiographic system, and what does it assess?
By evaluating the position of the x-ray beam relative to the detector
After completing a PA chest radiograph, you notice it has a giant appearance. Which postprocessing adjustment is most appropriate to address this issue without compromising resolution?
Increase noise reduction algorithms
What role does the AEC test play in a digital radiography quality assurance?
It ensures the AEC adjusts exposures levels accurately
What does a DAP (dose area product) meter primarily measure during radiographic procedures?
The radiation exposure in the area being imaged
Which of the following best describes the function of a histogram in the context of image processing?
It plots the frequency of each pixel intensity value in the image
What is a common feature of a compensating filter used in radiography?
It equalizes the density of images of body parts with varying thickness
When post-processing a digital image, which technique is used to selectively enhance specific areas of interest without affecting the entire image?
ROI (region of interest) processing
A material that does NOT allow the flow of electrons is known as an:
Insulator
What is the most significant benefit of utilizing advanced image processing algorithms in digital radiography?
They improve image resolution and detail extraction
In a MIMPS, what is the primary function of the DICOM standard?
To facilitate the interoperability of medical images
Which area of the x-ray tube is struck by electrons during an x-ray exposure?
Actual focal spot
What is the advantage of using an LUT during image processing?
Enhances image contrast and brightness
X-ray photons emitted during fluoroscopy are primarily absrobed by the:
Patient
How does the implementation of MIMPS impact the workflow in a radiology department?
It simplifies the sharing and accessibility of imaging studies
What determines the transformer ratio?
Number of turns of the wire on the primary and secondary side
Which two of the following image receptor designs is/are used in direct radiography (DR) imaging equipment?
- Wired flat-panel detectors
- Wireless flat-panel detectors
Which factor is most important when assessing the quality of imaging informatics systems?
Accuracy of data conversion
What is the primary reason for using a high-voltage transformer in x-ray machines?
To increase the voltage to a level suitable for x-ray production
A radiologic technologist is setting up a mobile radiograph unit for a bedside chest x-ray. Which component is crucial for adjusting the X-ray beam intensity according to the patient size and tissue density?
X-ray generator
Why is it important to evaluate the dynamic range in digital radiography?
It defines how well the system can capture varying degrees of radiation
Which factor most directly affects the sharpness of images in digital radiography?
The pixel density of the display monitor
Which of the following tests is essential for ensuring the correct operation of the automatic exposure control (AEC) system in a radiographic unit?
Density control accuracy
A radiographer wants to reduce the appearance of scatter radiation on a digital image. Which technique should be employed?
Use a grid
What is the importance of high contrast resolution in digital radiography display monitors?
It enables effective differentiation between very similar tissue densities
When calibrating a radiographic display system, which step is crucial to ensure that it meets diagnostic imaging requirements?
Performing a uniformity correction across the display
Automatic brightness stabilization (ABS) is designed to compensate for changes in:
Tissue density
What does a grid performance test in radiography evaluate?
The effectiveness of scatter radiation reduction
In radiography, what is the purpose of using a grid with higher grid ratios?
To increase the potential for scatter radiation absorption
A radiology department is experiencing inconsistencies in image quality across different examination rooms. What is the first step in standardizing image quality for diagnostic accuracy?
Calibrating all radiographic display monitors to the same standard
Which type of test is crucial for verifying the protective lead aprons used in radiographic procedures?
Fluoroscopic examination for defects
During image processing, a technologist applies edge enhancement to an image. What is the primary outcome of this processing technique?
Enhanced visibility of edges and fine details
During fluoroscopy, how does the use of an image intensifier primarily benefit the patient?
It reduces the dose of radiation required to form an image
Which of the following operations results in edge enhancement?
High-pass filtering
During an inspection, a radiologic technologist observes that digital radiographs are consistently appearing too dark, despite correct exposure parameters. Which setting adjustment on the display monitor is most likely to rectify this issue?
Adjust the luminance settings
