1
When x-rays interact with body tissues causing some to be absorbed and others to pass through, this process is known as:
A. Photon transmission
B. Differential absorption
C. Beam filtration
D. Energy conversion
B. Differential absorption
Image magnification increases with:
A. Decreased OID
B. Increased SID
C. Increased OID
D. Small focal spot
C. Increased OID
To keep IR exposure constant, if exposure time is increased, mA must be:
A. Decreased
B. Increased
C. Doubled
D. Unchanged
A. Decreased
The reciprocity law states that different mA/time combinations producing the same mAs yield:
A. Different exposures
B. Equal exposures
C. Decreased contrast
D. Increased contrast
B. Equal exposures
Beam attenuation increases with:
A. Greater tissue thickness
B. Higher atomic number
C. Lower kVp
D. All of the above
D. All of the above
The reduction in x-ray energy as it moves through matter is termed:
A. Attenuation
B. Refraction
C. Absorption
D. Transmission
A. Attenuation
The exposure factor that controls beam penetration is:
A. kVp
B. mA
C. SID
D. Exposure time
A. kVp
When the SID is reduced, the beam intensity at the IR will:
A. Increase
B. Decrease
C. Remain constant
D. Drop to zero
A. Increase
Reducing mAs by 50% will reduce IR exposure by:
A. 10%
B. 25%
C. 50%
D. 100%
C. 50%
A material with a higher atomic number will exhibit:
A. Less attenuation
B. Greater transmission
C. More attenuation
D. More scatter only
C. More attenuation
When an x-ray photon passes through the patient without interacting, it undergoes:
A. Absorption
B. Scatter
C. Transmission
D. Attenuation
C. Transmission
Which interaction does not occur in the x-ray tube?
A. Heat production
B. Compton scattering
C. Characteristic radiation
D. Bremsstrahlung radiation
B. Compton scattering
To maintain exposure when SID changes, the radiographer uses the:
A. 15% rule
B. Exposure maintenance formula
C. Inverse square law
D. Reciprocity law
B. Exposure maintenance formula
To increase IR exposure using the 15% rule, you should:
A. Increase kVp by 15%
B. Decrease kVp by 15%
C. Increase mAs by 15%
D. Decrease SID by 15%
A. Increase kVp by 15%
Increasing the object-to-image distance (OID) will:
A. Improve sharpness
B. Increase magnification
C. Reduce distortion
D. Decrease penumbra
B. Increase magnification
The difference in brightness levels between adjacent structures on an image is described as:
A. Contrast
B. Density
C. Distortion
D. Sharpness
A. Contrast
The fuzzy edge surrounding the image of an object is called:
A. Umbra
B. Penumbra
C. Divergence
D. Resolution
B. Penumbra
Which distance will produce the highest IR exposure?
A. 36 in
B. 44 in
C. 56 in
D. 72 in
A. 36 in
Which rule allows maintaining image exposure while lowering patient dose?
A. Inverse square law
B. 15% rule
C. Reciprocity law
D. Beam hardening
B. 15% rule
As tissue thickness increases, the amount of x-ray absorption:
A. Decreases
B. Stays the same
C. Increases
D. Becomes unpredictable
C. Increases
The geometric misrepresentation of the size or shape of an object on an image is known as:
A. Distortion
B. Noise
C. Density
D. Magnification
A. Distortion
A radiograph that appears very black and white has ______ contrast and a ______ scale.
A. High; short
B. Low; long
C. High; long
D. Low; short
A. High; short
According to the 15% rule, increasing kVp by 15% has the same effect as:
A. Halving the SID
B. Halving the mAs
C. Doubling the SID
D. Doubling the mAs
D. Doubling the mAs
Longer wavelength photons indicate:
A. Higher kVp
B. Lower kVp
C. More penetration
D. Shorter exposure time
B. Lower kVp
Subject contrast is determined by:
A. Tissue composition
B. kVp level
C. Patient thickness
D. All of the above
D. All of the above