IP - Image Acquisition Flashcards
In situations where a prosthetic device is present, which two 2) options would a radiologic technologist have when
using AEC? Select two) options
Disable AEC and manually set exposure parameters
Position the device directly over the AEC detectors
Avoid positioning the device directly over the AEC detectors
Increase the sensitivity of the AEC detectors
Disable AEC and manually set exposure parameters
Avoid positioning the device directly over the AEC detectors
If the technologist cannot avoid positioning the prosthetic directly over the AEC detectors, it is advisable to disable AEC and manually set exposure parameters. It is also advisable to avoid positioning the prosthetic device directly over the AEC detectors, as this could lead to incorrect readings and inappropriate exposure settings. The device’s material might absorb or scatter the radiation unpredictably, resulting in either an under or overexposed image. Positioning the prosthetic directly over the detectors or increasing detector sensitivity would likely exacerbate exposure issues.
Which image processing setting would most effectively enhance contrast resolution in a low-contrast image?
Increasing kVp
Adjusting the window width
Adjusting the window level
Applying a high-pass filter
Adjusting the window width
Adjusting the window width specifically modifies the contrast levels within the image, making it easier to distinguish between subtle differences in tissue densities. This adjustment is particularly beneficial in low-contrast situations. Increasing kVp primarily affects image penetration and could potentially decrease contrast. Adjusting the window level affects the image brightness rather than the contrast. Applying a high-pass filter enhances edges but may not necessarily improve overall contrast resolution.
How does an increase in kVp settings affect AEC operation during a radiographic exam of the thorax?
It leads to an increase in exposure time as AEC compensates for increased photon penetration
It generally results in shorter exposure times due to the higher energy of the X-ray
Increases the sensitivity of the AEC detectors, leading to longer exposure time
Has no impact on AEC operation since kVp only affects image contrast
It generally results in shorter exposure times due to the higher energy of the X-ray
Increasing the kVp settings during a thoracic radiographic exam generally results in shorter exposure times. This is because the higher energy X-rays penetrate more easily through the tissues, reducing the amount of radiation needed to achieve adequate image density as perceived by the AEC detectors. Therefore, the AEC typically responds by shortening the exposure time to avoid overexposure. Increasing kVp does not increase detector sensitivity, and changes in kVp directly influence AEC operations by affecting the penetration of X-rays, not just contrast.
How does the application of a low-pass filter impact the appearance of a digital radiographic image?
Increases image contrast
Increases visibility of large structures
Enhances overall image brightness
Reduces image noise
Reduces image noise
Applying a low-pass filter provides a smoothing effect to the image, reducing noise and contrast by filtering out high frequencies. This can be beneficial for viewing small
structures and fine details. Low-pass filtering decreases contrast, does not specifically enhance large structures, and does not directly affect brightness.
Which component collects the electrical signal in indirect digital receptors?
Scintillator
Photodiode
Detector array
Photocathode
Detector array
The detector array in indirect digital receptors captures the x-rays that pass through the patient and converts them into an electrical signal, forming the basis of the digital image. The x-ray tube generates x-rays but does not collect the electrical signal. The computer processing unit processes the signal into an image, and the display monitor shows the final image.
Which of the following changes to AEC settings would be most appropriate when imaging a patient with ascites?
Decrease the sensitivity of the AEC detectors
Increase the sensitivity of the AEC detectors
Shorten the backup time
Use a lower energy X-ray beam
Decrease the sensitivity of the AEC detectors
For a patient with ascites, decreasing the sensitivity of the AEC detectors is appropriate because the added fluid in the abdomen can absorb more X-rays, requiring a longer exposure to achieve optimal image quality. Increasing the
sensitivity would likely result in underexposure, while shortening the backup time and using a lower energy X-ray beam could also lead to inadequate imaging of the area.
How does the orientation of the anode-cathode axis in the x-ray tube affect image sharpness during extremity imaging?
It has no effect on sharpness
Orientation parallel to the limb increases sharpness
Orientation perpendicular to the limb increases sharpness
Orientation impacts only the exposure time
Orientation parallel to the limb increases sharpness
The orientation of the anode-cathode axis in the x-ray tube can significantly affect image sharpness, particularly in extremity imaging. Orienting the axis parallel to the
length of the limb utilizes the anode heel effect to enhance sharpness and detail, as the intensity of the x-ray beam is more uniformly distributed across the imaged area.
