x ray production and emission

projectile electrons must have an energy of at least __________keV to produce k characterisitc x rays from tungsten a. 50 b. 70 c. 67 d. 58

b. 70

If the distance from the source to the image (SID) is reduced by half, how is the x-ray intensity at the image affected? a. It is reduced by 1/2. b. It is increased 4 times. c. It is reduced by 1/4. d. It is doubled.

b. It is increased 4 times.

characteristic radiation is produced when a. electrons are stopped at the cathode b. a vacancy in electron orbit is filled c. a vacancy in nucleus is filled d. electrons are stopped at the anode

b. a vacancy in electron orbit is filled

brems produces a _______ energy a. discrete b. continuous c. kinetic d. filtered

b. continuous

An increase in mAs would ____ the ____ of the emission spectrum. a. increase, amplitude and position b. increase, amplitude only c. not affect, amplitude and position d. increase, position only

b. increase, amplitude only

If x-ray quantity is doubled, the optical density on the finished radiograph will be a. just slightly increased. b. increased by a factor of two. c. increased by a factor of four. d. reduced by half.

b. increased by a factor of two.

a kvp is increased, the production of brems photons a. decreases b. increases c. is replaced by characteristic interactions d. remains the same, but lower energy ranges are observed

b. increases

beam quality is primarily determined by a. mA b. kVp c. target angle d. focal spot size

b. kVp

A low quality beam would also have low a. quantity. b. penetrability. c. intensity. d. mAs.

b. penetrability.

The half value layer (HVL) of an x-ray beam is a measurement of beam ____. a. intensity b. quality c. quantity d. All of the above.

b. quality

The penetrability of an x-ray beam is called x-ray ____. a. quantity b. quality c. intensity d. All of the above.

b. quality

The ____ of an x-ray beam is higher when the peak of the emission spectrum is further to the ____. a. quantity, left b. quality, right c. quantity, right d. quality, left

b. quality, right

The discrete portion of the x-ray emission spectrum would change position with a change in ____. a. kVp b. target material c. voltage rippled. Both a and b.

b. target material

which factors affect the characteristic radiation emitted from the x ray tube? a. mA b. kVp c. filtration d. anode material

both a and d

which of the following types of radiation can not be produced at tube potentials of less than 70 keV? a. brems b. scatter c. characteristic d. primary

c. characteristic

the cascade process is associated with a. molybdenum targets b. brems radiation production c. characteristic radiation production d. filtration effects

c. characteristic radiation production

1 out of 1 points If a technologist changes the technique from 70 kVp @ 200 mAs to 70 kVp @ 400 mAs, then the x-ray intensity will ____ and optical density will ____. a. will remain the same, double b. double, remain the same c. double, double d. remain the same, will remain the same

c. double, double

Beam quality is affected by a. mAs and distance. b. filtration and mAs. c. kVp and filtration. d. kVp and mAs.

c. kVp and filtration

the max kinetic energy of a projectile electron accelerated across an x ray tube on the a. atomic number Z of the target b. size of the focal spot c. kilovoltage d. type of rectification

c. kilovoltage

x ray tube filtration filters out a. low energy electrons b. high energy electrons c. low energy x rays d. high energy x rays

c. low energy x rays

X-ray quantity increases in direct proportion to increases in ____. a. filtration b. distance c. mAs d. kVp

c. mAs

The number of useful x-rays in the beam defines x-ray a. kVp. b. quality. c. quantity. d. mAs.

c. quantity.

How does added filtration affect the emission spectrum? a. increased amplitude and a shift to the right b. reduced amplitude and a shift to the right c. reduced amplitude and a shift to the left d. increased amplitude and a shift to the right

c. reduced amplitude and a shift to the left

If 90 kVp is selected when a tungsten target is used a. the maximum energy of the projectile lectrons and the subsequent x ray photons will be equal to 30 keV b. characterisitc photons will be emitted at the 30 and 90 keV c. the kinetic energy of the projectile electrons will be equivalent to this energy and the Emax of the x ray beam will be 90keV

c. the kinetic energy of the projectile electrons will be equivalent to this energy and the Emax of the x ray beam will be 90keV

mA decreased

causes peaks (amplitude) of graph to decrease

target Z decreased

characteristic radiation appears in new positions

An exposure taken at 100 kVp would have a continuous emission spectrum with a maximum energy of ____ keV. a. 69 b. 140 c. 30 d. 100

d. 100

If an exposure is 50 mR at an SID of 40 inches, what would the exposure be at an SID of 60 inches? a. 75 mR b. 33.3 mR c. 112.5 mR d. 22.2 mR

d. 22.2 mR

more than _____ percent of an x ray beam is made up of photons produced by the brems process a. 1 b. 10 c. 80 d. 90

d. 90

Image contrast is affected by ____. a. beam quality b. kVp c. mAs d. Both a and b.

d. Both a and b

Changes in ____ result in directly proportional changes in the amplitude of the emission spectrum. a. mA b. time c. kVp d. Both a and b.

d. Both a and b.

If filter thickness is ____, then x-ray intensity is ____. a. reduced, reduced b. increased, reduced c. reduced, increased d. Both b and c.

d. Both b and c.

the process of removing low energy photons from the x ray beam is called a. rectification b. ionization c. electron transition d. filtration

d. filtration

influences the intensity and average energy of the x ray beam by eliminating low energy photons

filtration

influences the intensity and the average energy of the x ray beam by making the x ray tube more efficient

generator

controls the projectile electron energy, the intensity, the maximum energy, and the average energy of the x ray beam

kVp

controls the number of projectile electrons striking the anode and the intensity of the x ray beam

mAs

filtration increased

shifts minimum energy of spectrum to the right

An increase of 15% in kVp is equivalent to increasing density or mAs by ____. a. 100% b. 30% c. 50% d. 15%

a. 100%

after electrons strike the anode of an x ray tube the majority of the energy is converted to a. heat b. brems photons c. characteristic photons d. kinetic

a. heat

An increase in kVp would ____ the ____ of the emission spectrum. a. increase, amplitude and position b. not affect, amplitude and position c. increase, amplitude only d. increase, position only

a. increase, amplitude and position

added filtration will ____ beam quality and ____ beam quantity. a. increase, decrease b. decrease, decrease c. increase, increase d. decrease, increase

a. increase, decrease

The amplitude of the emission spectrum is ____ with a ____ generator than/as with a three-phase generator. a. lower, single-phase b. lower, high frequency c. the same, single-phase d. higher, single-phase

a. lower, single-phase

a technologist can control the quantity of the x rays striking the patient by adjusting the a. mA b. kVp c. rectification d. anode material

a. mA

beam quantity is primarily determined by a. mA b. kVp c. target angle d. focal spot size

a. mA

The quantity of bremsstrahlung radiation increases proportionately with increased ____. a. mAs b. added filtration c. rotor speed d. kVp

a. mAs

The main purpose of added filtration is to reduce a. patient dose. b. the HVL. c. beam penetrability. d. beam quality.

a. patient dose.

An x-ray beam that could pass through dense tissue would have high ____. a. penetrability b. quality c. quantity d. Both a and b.

a. penetrability

when an incident electron approaches a positively charged nucleus of a tungsten atom, a. the incident electron slows down due to electrostatic attraction b. the incident electron penetrates the nucleus c. a cascade of electrons from each orbital shell is initiated a d. a characteristic photon is emitted

a. the incident electron slows down due to electrostatic attraction

kVp increased

amplitude, maximum energy, and average energy all increase

which of the following can be determined from an x ray emission spectrum? 1. photon Emax 2. photon velocity 3. average photon energy a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1, 2, and 3

b. 1 and 3

changing ______ will change Emax of the photons in the x ray emission spectrum 1. mA 2. kVp 3. filtration 4. anode material a. 1 only b. 2 only c. 2 and 3 d. 2, 3, and 4

b. 2 only