X-Ray Production, Emission, & Interaction with Matter TEST

What are low energy x-ray photons in the 10-15 keV range called?

 

brems rays

 

grenz rays

 

characteristic rays

 

mega rays

grenz rays

Modified scatter refers to which of the following interactions?

 

compton

 

photoelectric

 

classic

 

pair

compton

What percentage of the radiation produced in an x-ray tube is a result of brems interactions?

 

80%

 

10%

 

90%

 

69%

90%

In a tungsten target x-ray tube, which of the following characteristic x-rays are useful in producing a radiographic image?

 

M shell

 

L shell

 

P shell

 

K shell

K shell

As the kV is increased, how is the x-ray tube efficiency affected?

 

increases

 

decreases

 

remains the same

increases

How efficient are most ordinary diagnostic x-ray machines in the production of radiation?

 

50%

 

10%

 

1%

 

99%

1%

Increasing the energy of the electrons across the x-ray tube will result in photons with a              .

 

high speed, longer wavelength

 

higher frequency, shorter wavelength

 

higher frequency, lower speed

 

longer wavelength, lower frequency

higher frequency, shorter wavelength

What percentage of the radiation produced in an x-ray tube is a result of useful characteristic interactions?

 

80%

 

69%

 

90%

 

10%

10%

Which of the following interactions involves a photon collision with a loosely bound electron and formation of a scattered photon?

 

compton

 

photoelectric

 

Thompson

 

unmodified

compton

A photoelectric interaction most likely involves a collision with a/an               shell electron.

 

N

 

L

 

M

 

K

K

During normal x-ray production much energy is lost in the form of                 .

 

light

 

sound

 

heat

 

magnetism

heat

Which of the following would increase x-ray quantity?

 

decrease in exposure time

 

increase in tube current

 

decrease in kV

 

none of the above

increase in tube current

A diagnostic radiograph of skull requires 200 mA, 0.1 s, and 60kV. The radiologist determines the contrast is too high and wants a more gray image. How could you change this technique to make a lower contrast image (kV would need to be increased).

 

51 kV, 10mAs

 

69 kV, 20 mAs

 

51 kV, 5 mAs

 

69 kV, 10 mAs

69 kV, 10 mAs

Which of the following interactions contributes most to patient dose?

 

photoelectric effect

 

compton scatter

 

classical scatter

 

thompson scatter

photoelectric effect

What is the primary controlling factor of beam quality?

 

milliamperes

 

time

 

kV

 

filtration

kV

As the atomic number is decreased, the strength of the characteristic radiation is               .

 

increased

 

decreased

 

does not change

decreased

What device may be used to offset the difference in subject density (body thickness)?

 

penetrometer

 

Victoreen R meter

 

cutie pie

 

compensating filter

compensating filter

What is the minimum kV level necessary to produce useful characteristic radiation in the x-ray tube?

 

50

 

90

 

69

 

75

69

What minimum energy is required for pair production to occur?

 

1.02 MeV

 

1.05 MeV

 

1.35 MeV

 

10 MeV

1.02 MeV

In which interaction is nuclear fragment ejected?

 

pair production

 

photodisintegration

 

characteristic radiation

 

annihilation reaction

photodisintegration

Which of the following interactions would result in a 40 keV photon striking an electron with 70 keV binding energy, and a 40 keV photon is scattered?

 

backscatter

 

compton scatter

 

modified scatter

 

unmodified scatter

unmodified scatter

What is the amount of added filtration in the x-ray tube?

 

2.0 mm Al

 

2.5 mm Al

 

2.5 mm Pb

 

2.0 mm Al

When using a wedge filter, which end would be placed toward the hip in a femur exam?

 

thick end

 

thin end

thin end

Given the following data, what is the half value layer of the unfiltered x-ray beam whose initial value is 82 R/min?

	mm Al	Exposure Rate
a.	0.5 mm	73 R/min
b.	1.0 mm	54 R/min
c.	1.5 mm	41 R/min
d.	2.0 mm	32 R/min

 

a

 

b

 

c

 

d

c

As the filtration in an x-ray tube is increased, radiation quantity reaching the image receptor is              .

 

increased

 

decreased

 

stays the same

 

decreased

As kV increases, the HVL                  .

 

increases

 

decreases

 

does not change

increases

As the atomic number increases, characteristic radiation will                .

 

increase

 

decrease

 

does not change

increase

As the mAs is increased, the strength of characteristic radiation in the x-ray tube will                .

 

increase

 

decrease

 

not change

not change

If the kV selected was 90 kV, the peak or average energy of the x-ray beam would be about                 kV.

 

90

 

60

 

0

 

30

30

As filtration is increased, the effective energy of the beam is                         .

 

increased

 

decreased

 

not changed

increased

The annihilation reaction occurs in which of the following interaction?

 

compton

 

pair production

 

photoelectic

 

photodisintegration

pair production

Which of the following would be the same as increasing the kV by 15%

 

halving the mAs

 

increasing the mAs by 4

 

doubling the mAs

 

decreasing the mAs by 4

doubling the mAs

At what level does photodisintegration occur?

 

10 keV

 

1.02 MeV

 

100 keV

 

10 MeV

10 MeV

Which of the following is not an ionization chamber?

 

compensating filter

 

Geiger-Muller

 

Cutie Pie

 

Victoreen R meter

compensating filter

As the distance is increased, x-ray quantity reaching the image receptor is                  .

 

increased by the distance squared

 

decreased by the distance squared

 

decreased by 1/2

 

increased 2 times

decreased by the distance squared