Chapter 26 (Module 1) Flashcards
Assessment of digital radiographic image quality includes:
a. looking at the window/level values on the monitor
b. electronic masking the image to improve the exposure indicator value
c. postprocessing the image to enhance image contrast
d. referencing exposure indicators values for acceptance
Referencing exposure indicators values for acceptance
Digital image artifacts such as vertical or horizontal lines, opaque, white lines demonstrates:
a. underexposure
b. excessive exposure
c. quantum noise
d. system noise
Excessive exposure
The brightness of the image on a viewing monitor is
a. the result of receptor exposure.
b. the result of the tissue density.
c. the result of the tissue thickness.
d. a function of the monitor.
A function of the monitor
The principal controlling factor of radiographic receptor exposure is
a. kVp.
b. mAs.
c. focal spot size.
d. filtration thickness.
mAs
Which statement is TRUE?
a. As mAs increases, scatter decreases.
b. As mAs decreases, quantum noise can appear.
c. As mAs increases, remnant radiation decreases.
d. As mAs decreases, exposure increases logarithmically.
As mAs decreases, quantum noise can appear
The minimum change necessary to improve the appearance of noise on a digital image is ____ percent of mAs.
a. 10–12
b. 25–35
c. 50–60
d. none of the above
25-35
Which generator type produces the least amount of receptor exposure per mAs?
a. single-phase, 2-pulse
b. three-phase, 6-pulse
c. three-phase, 12-pulse
d. a high-frequency generator
Single-phase, 2-pulse
Which generator produces the greatest amount of receptor exposure per mAs?
a. single-phase, 2-pulse
b. three-phase, 6-pulse
c. three-phase, 12-pulse
d. a high-frequency generator
A high-frequency generator
Which rule is used as a guide to maintain the same receptor exposure, when kVp changes?
a. doubling rule
b. 15% rule
c. inverse square rule
d. density maintenance law
15% rule
Which factor influences the number of photons reaching the IR?
a. kVp
b. mAs
c. focal spot selection
d. exposure time
mAs
Which factor influences the number of photons reaching the IR?
a. kVp
b. mAs
c. focal spot selection
d. exposure time
mAs
Which factor influences the average energy of photons reaching the IR?
a. kVp
b. mAs
c. focal spot size
d. mA
kVp
The 15% rule will affect
a. recorded detail.
b. image brightness.
c. distortion.
d. none of the above.
None of the above
The relationship between exposure and SID is
a. directly proportional.
b. inversely proportional to the cube of the distance.
c. directly proportional to the square of the distance.
d. inversely proportional to the square of the distance.
Inversely proportional to the square of the distance
Moderate increases in kVp with a digital receptor, will produce
a. dramatic changes in image contrast.
b. a change in entrance skin exposure.
c. no change in image brightness.
d. both b and c.
Both b and c
What conclusion can you reach regarding an image with an S# of 750 and good image brightness on the display monitor?
a. The image is likely to demonstrate noise or quantum mottle.
b. There was not enough exposure to create a good histogram.
c. The noise level will be at a minimum and the image will look good in the magnification mode.
d. The IR received too much exposure.
The image is likely to demonstrate noise or quantum mottle.
You have completed a chest radiograph using 3 mAs @ 110 kVp. The image shows obvious under penetration of the mediastinal anatomy. The professional radiographer would
a. increase kVp by 3 kVp and repeat the exposure.
b. use the 15% Rule and reduce the kVp and increase the mAs.
c. increase the kVp to 120 kVp and repeat the exposure at the same mAs.
d. remove the beam filtration and repeat the exposure.
Increase the kVp to 120 kVp and repeat the exposure at the same mAs.
In the event of making a single exposure that is critical to the exam success, most experienced technologists will
a. use slightly less mAs than necessary to prevent overexposure.
b. overexpose the IR slightly.
c. provide enough exposure to create an adequate histogram or permit viewing a film with a bright light.
d. both b and c.
Both b and c
In the case of film radiography,
a. the response to exposure is linear.
b. the response to radiation exposure is inverse.
c. the response to exposure is logarithmic.
d. the response to exposure is exclusively a function of kVp.
The response to exposure is logarithmic
Image brightness on an image display monitor is controlled by
a. window level.
b. window width.
c. EI number.
d. S number.
Window level
The effect of mAs upon IR exposure is
a. inverse.
b. inversely proportional.
c. directly proportional.
d. dependent upon kVp.
Directly proportional
Optimum exposure to a digital detector system
a. varies between manufacturers.
b. is a function of acceptable noise levels.
c. is identified with target exposure index values.
d. all of the above.
All of the above
As you analyze your image, you come to the conclusion that it must have more exposure. As a general rule, you should increase
a. kVp.
b. mAs by 2X.
c. the SID.
d. mAs by a 0.5 multiplier.
mAs by 2X.
A change in kVp, as an exposure factor, affects
a. average beam energy.
b. beam intensity.
c. the amount of scatter production.
d. all of the above.
All of the above
The greatest factor in the production of scatter radiation is
a. kVp.
b. mAs.
c. patient thickness.
d. patient position.
Patient thickness
Radiographic room A is a three-phase, six-pulse generator. Room B is a high-frequency generator. When going between these two rooms to perform examinations, what exposure modification is necessary to produce comparable exposure density?
a. Use 15 percent more with the three-phase system.
b. Use 10 percent more with the high-frequency system.
c. No change is required between the two systems.
d. Use 10 percent less with the high-frequency system.
No change is required between the two systems
Focal spot blooming occurs with
a. high kVps.
b. high mA exposures.
c. large SIDs.
d. extreme tube angulation.
high mA exposures
Because of the “heel effect,” x-ray beam intensity
a. is greater under the cathode side of the tube.
b. is greater under the anode side of the tube.
c. is equal across the beam long axis.
d. changes with patient position.
is greater under the cathode side of the tube
The anode heel effect is more pronounced with
a. smaller field sizes (8” × 10”).
b. stationary anodes.
c. a 10− degree target angle.
d. rotating anodes.
a 10 degree target angle
When changing your SID from 72” to 56”
a. decrease your kVp by 15 percent.
b. decrease your mAs by 50 percent.
c. increase the mAs by a factor of 4.
d. increase the kVp by 15 percent.
decrease your mAs by 50 percent
All of the following will decrease digital receptor exposure EXCEPT
a. increased grid ratios.
b. increased beam angulation from 5 degrees to 10 degrees.
c. increased OID.
d. increased filtration.
increased beam angulation from 5 degrees to 10 degrees
