The Compilation Flashcards
Increasing kVp by 15% results in an increase in patient exposure of approx:
33%
The absorption and scattering of the x-ray beam as it passes through the body is best referred as:
attenuation
The signal to noise ratio should always be greater than the
1
At high kVp levels, which interaction of photons with matter is most likely to take place?
Compton
An incident x-ray photon within the patient has 106 kV of energy. An L-Shell electron with a BE of 3 kV speeds away from the atom, carrying 4 kV of kinetic energy. A Compton scattered photon from this interaction must have _____ of energy.
99 kV
Which x-ray interaction within the patient results in total absorption of the photon’s energy, and leaves a microscopic “white” spot wherever it occurs in the resulting image?
Photoelectric interaction
Increasing this technical factor will only lead to an increase in x-ray beam intensity to the IR and will not affect other factors such as contrast or detail:
mAs
Ionization does not occur in which one of the following?
-Photoelectric Absorption
-Compton Scatter
-Coherent Scatter
-Ionization does not occur in any of these interactions?
Coherent Scatter
What is the magnification factor of magnification of an object imaged with an SID of 72” and an OID of 8”
1.125
The sharpness in an image is affected by all of the following EXCEPT:
mAs
SOD
OID
focal spot size
mAs
Compton Effect
The energy of the incident x-ray photon is partially absorbed by an outer-shell electron, which is then ejected from the atom as a recoil electron.
Milliamperage is a unit for measuring the:
Electrical current flowing during an exposure.
In order to adjust radiographic technique to compensate for a body part that is 4 cm thicker than average, mAs should be:
Increased by 100%
A 10kV photon undergoes a coherent scattering interaction with an orbital electron having a BE of 2kV. What is the energy of the resulting scattered photon?
10 kV
Coherent has the same number of energy going out as it did going in. Temporarily absorbed by the atom and then exits the body as a scatter photon with same energy the x-ray photon had before entering.
A photon with slightly more energy than the binding energy of the tissue through which it passes will most likely interact by:
Photoelectric effect
A kidney that measures 6 cm is radiographed using an SID of 48 and an SOD of 40. How many centimeters will the kidney measure on the completed radiograph?
7.2 cm
What exposure factor regulates x-ray beam quality?
kVp
Approximately what percentage of the x-ray beam is absorbed for every 4 cm of tissue as it passes through the body
50%
Smaller focal spot sizes result in less
Which one:
A. Magnification.
B. Off focus radiation.
C. Occupational exposure.
D. Penumbra
Penumbra
Grids should generally be used for anatomy thicker than
10cm
Why would a rad tech use a small focal spot while performing a radiographic examination? Pick one:
A. Increase the penumbra
B. Obtain fine details
C. Increase magnification of the image
D. Reduce exposure to the patient
Obtain fine details
Which of the following conditions would require a decrease in radiographic technique?
Cirrhosis
Osteopetrosis
Bowel obstruction
Hydrocephalus
Bowel obstruction
The Lightfield can deviate from the radiation field by ____ of SID
2%
With all other factors remain remaining the same, if .5 mm of filtration is added to the Primary beam, this factor will INCREASE
Average KVP
