V2 - Image Production Flashcards
Which factor will increase x-ray beam quantity at the IR without increasing heat units produced by the tube?
Decreased filtration
A breathing technique is planned for a RAO sternum radiograph. The intended exposure is 50 mAs at 75 kVp at 100 cm SID. Which mA station is preferred, assuming the radiographer ensures exposure occurs during the act of inspiration?
50
Which is one function of a picture archiving and communication system (PACS) network?
Downloading images from different imaging modalities
Which term refers to the process by which digital radiography (DR) systems adjust for exposure errors so that the image is displayed with proper brightness and contrast levels?
Automatic rescaling
Which description best defines a histogram?
Graph where x-axis is the amount of exposure read, and the y-axis is the number of pixels
Which best describes anode heel effect?
A phenomenon where x-ray intensity is greater under the cathode
Which term refers to unwanted fluctuations in the brightness of an image?
Noise
Why is it important for the radiographer to observe the mAs readout at the end of each exposure when using AEC?
This value may be used as a basis for calculating manual techniques
Historically, rhenium was alloyed to the tungsten in the filament of valve tubes to increase electron emission. What is the major reason that isn’t used in x-ray tube filaments?
To permit fine control of electron emission by filament heating current
What is the result if the total lead content of a grid is decreased?
Decreased scatter absorption
Which factor would the radiographer choose to maximize recorded detail in the image?
Small focal spot
Pelvis routine calls for an AP with a perpendicular CR, and an axial AP with a 40 degree cephalic angle. Using a caliper measurement, the technique chart yields a perfect set of exposure factors for the perpendicular AP. How will the necessary exposure factors for the axial differ from the perpendicular AP?
Greater measurement, higher kVp and mAs
What could cause a CR image with very noticeable lines uniformly in the same direction over the entire image? (3)
Noise resulting from the plate reader electronics. Grid used with grid frequency equal to the image reader’s laser scan lines. Grid utilized with grid lines running parallel to the laser scan lines of the image reader device.
What would a continuous, fine, horizontal white line across the CR image indicate?
Dirt on the light guide or laser head
Which material is used on most anode disks and is light, strong, and heat-resistant?
Molybdenum
An imaging department, having difficulty obtaining acceptable tangential patella images, has opted to have the post processing mode set to “fixed” for all patella images. Why is this a good choice?
Fixed mode works well for exams where it is difficult to center the image on the IR
A step up transformer with 300 turns in the primary coil is supplied with 220 volts to this primary. How many secondary turns are needed to produce a 66,000 volt output?
90,000 turns
Which is the preferred method for indicating the correct anatomic side on a radiographic image?
Place the side marker directly on the IR prior to exposure
If a radiographer wanted to double image density without doubling the patient’s dose, which action should be taken?
Increase kVp by 15%
In order to increase the number of shades of gray displayed on a digital image what should be done?
Increase window width
What results from utilizing a lower grid ratio?
Lower contrast, but greater error of margin in CR placement
How does emphysema impact radiographic imaging of the chest?
Emphysema is a destructive disease, meaning the chest tissue is more radiolucent
Which component of radiographic noise in digital imaging is controlled by the radiographer?
Quantum mottle
Digital radiography has the ability to produce 16,000 shades of gray. What appropriate bit depth (dynamic range) does this represent?
14 bit depth
