List the four primary image quality factors
Density
Contrast
Detail
Distortion
The amount of blackness on a processed radiograph is called
Density
What exposure factor primarily controls radiographic density
mAs
True/False
For an underexposed radiograph, the mAs must be increased by a factor of four to produce a visible change in radiographic density.
False
A radiograph of the knee reveals that it is overexposed and must be repeated. The original technique used was 10 mAs. What change will improve the image during the repeat exposure?
Decrease to 5 mAs
The primary controlling factor for radiographic contrast is:
kV
Low contrast gives
long scale (110 kV, 10 mAs)
High contrast gives
short-scale (50 kV, 800 mAs)
True /False
kV is a secondary controlling factor for radiographic density.
True
True/False
A low kV technique (50 kV) produces a long-scale contrast.
False
A radiograph of the elbow reveals that it is over exposed. The technologist wants to adjust kV rather than mAs for the repeat exposure. This is contrary to common practice. The original analog exposure factors were 70 kV and 5 mAs. What new kV setting would reduce radiographic density by one-half?
60 kV and 5 mAs
What techniques or devices will reduce the amount of scatter radiation striking the IR?
Collimnation
Grids
Lower kV
True/False
Recorded detail or spacial resolution is optimal with a long object image receptor distance (OID) and a short SID.
False
What best controls involuntary cardiac motion artifact?
shortening the exposure time
What spacial resolution factors increase resolution and geometric sharpness?
small focal spot
increase in SID
decrease in OID
Rather than rely on the anode heel effect, what can be used to equalize density of specific anatomy?
Compensating filter
Which type of compensating filter is recommended for an AP projection of the shoulder?
boomerang
which type of compensation filter is recommended for an axiolateral hip projection?
wedge
which type of grid cutoff is created if the CR and the face of the grid are not perpendicular to each other?
off-level
which of the following projections require the use of a grid?
PA Hand
AP Abdomen
Axial calcaneus (heel)
AP Elbow
AP Abdomen
The misrepresentation of an object's size or shape projected on a radiograph is called:
Distortion
To minimize radiographic distortion how should SID and OID be manipulated?
Greater SID and shorter OID
True/False:
To best use the anode heel effect, the thinner aspect of the anatomic part should be placed under the cathode aspect of the x-ray tube.
False
The best method to reduce distortion of the joints of the hand is to keep the fingers __________ to the IR.
Parallel
Which of the following factors affects spatial resolution to the greatest degree?
Use of a grid
kV
Focal spot size
mAs
Focal spot size