Ch. 11 (Exp I) Flashcards
The factors that affect x-ray emission under the direct control of the radiographer are called the _____ factors.
Prime
The prime factors include all of the following except:
a. filtration
b. mAs
c. kVp
d. distance
a. filtration
Milliamperage-second (mAs) directly affects all of the following except:
a. beam quantity
b. beam intensity
c. beam quality
d. x-ray output
c. beam quality
The factors that directly affect x-ray quantity are:
mA and time
X-ray beam quality is numerically represented by the:
HVL
The factors that directly affect x-ray quality are:
kVp and beam filtration
If 1 coulomb is equal to 6.3 x 10^18 electron charges, how many electrons flow from cathode to anode in 1 second?
6.3 x 10^18
If 1 ampere equals a flow of 6.3 x 10^18 electrons per second, how many electrons flow from cathode to anode in 1 milliampere?
6.3 x 10^15
As the mA doubles, the number of electrons flowing from cathode to anode…
Increases twofold
The product of the tube current and exposure time is equal to:
x-ray beam quantity
The primary factor controlling x-ray beam quantity is determined by:
mAs
In order to increase radiographic film density by 40%, the radiographer would:
a. Change the mAs from 15 to 21 mAs
b. decrease the kVp by 40%
c. Increase the mAs by 20%
d. Decrease the distance by 40%
a. Change the mAs from 15 to 21 mAs
If the mAs of a radiograph is increased from 10 to 20, the resulting radiograph will exhibit:
Increased radiographic film density
The relationship between mAs and exposure is:
Directly proportional
The reaction of a photographic film to light is equal to the product of the intensity of the light and the duration of the light exposure. This concept is known as:
The reciprocity law
Increasing the energy of an incident electron will result in the production of an x-ray photon with:
Greater energy
If kVp is doubled, the amount of x-ray photons created approximately increases:
Fourfold
Kilovoltage is the primary controlling factor of:
Radiographic film contrast
An increase in kVp by 15 percent will cause an approximate _____ in the exposure.
Doubling
Adjustments in kVp should be used to control radiographic _______.
Contrast
X-ray beam penetrability is primarily controlled by _____.
kVp
The relationship between the intensity of radiation and distance is the…
Inverse square law
The density maintenance formula is a…
Direct square law
All factors remaining contrast, which of the following set of exposure conditions would yield an image with the greatest radiographic film density?
a. 100 mA, 0.75 sec, 40” SID
b. 300 mA, 0.25 sec, 44” SID
c. 600 mA, 125 ms, 40” SID
d. 400 mA, 200 ms, 40” SID
d. 400 mA, 200 ms, 40” SID
- Has highest mAs of 80 (all others at 75 mAs)
All factors remaining constant, which of the following set of exposure conditions would yield an image with the greatest radiographic film density?
a. 100 mA, 0.75 sec, 40” SID, 70 kVp
b. 150 mA, 0.25 sec, 44” SID, 80 kVp
c. 300 mA, 125 ms, 40” SID, 70 kVp
d. 400 mA, 187 ms, 56” SID, 88 kVp
d. 400 mA, 187 ms, 56” SID, 88 kVp
- Options a and d have 75 mAs (b and c have 37.5 mAs). d has a higher kVp than option a giving it more density than a.
After completing an upright abdomen radiograph using A.E.C., you notice some degree of motion artifact on the final image. To improve the repeat image results, your best option would be to:
a. Decrease the kVp
b. Increase your distance
c. Double the mA and decrease the kVp by 15%
d. Increase the kVp by 15%
d. Increase the kVp by 15%
Which of the following sets of exposure factors would best control involuntary motion?
a. 100 mA, 0.09 sec
b. 300 mA, 30 ms
c. 500 mA, 18 ms
d. 200 mA, 0.045 sec
c. 500 mA, 18 ms
- Has the shortest time.
The length of the exposure time (s) for a radiograph, is used to primarily control:
Motion
A radiograph is taken at 400 mA, 55 ms, 95 kVp. A second image could be taken to improve contrast at:
400 mA, 0.110 sec, 80 kVp.
-Double the mA, reduce kVp by 15%
