chapter 10 (x ray interaction with matter) Flashcards

1
Q

As Z _____, the probability of Compton scatter ____.

A

increases, remains the same

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2
Q

At energies less than ____ is the only time coherent scatter interactions are somewhat probable in soft tissue.

A

15 Kev

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3
Q

Compton scatter is directed at (a) ______ angle from the incident beam.

A

Any

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4
Q

When the mass density of the absorber is ____, it results in ____ Compton scatter.

A

increased, increased

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5
Q

K-shell binding energy increases with increasing

A

atomic number

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6
Q

The scattered X-Ray from a Compton interaction usually retains _______ of the energy of the incident X-Ray.

A

most

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7
Q

As kVp _____, the probability of Compton scatter ____

A

increases, decreases

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8
Q

An incident X-Ray interacts with an atom without ionization during ______.

A

coherent scattering

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9
Q

As kVp _____, the probability of coherent scatter ____

A

increases, decreases

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10
Q

At energies greater than ____ Compton scatter interactions become most probable in soft tissue.

A

25 keV

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11
Q

Materials with higher atomic numbers have lower _____.

A

transmission

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12
Q

__________ requires at least a 1.022 MeV X-Ray to occur.

A

Pair production

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13
Q

What is CT used for in PET/CT in nuclear medicine?

A

It shows better resolution images for anatomy and makes the PET image better

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14
Q

Which of the following is not one of the five basic X-Rays interactions with matter?

A

Bremsstrahlung

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15
Q

At ~20 keV, the main X-Ray interaction in soft tissue and bone is ______

A

photoelectric absorption

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16
Q

The two primary forms of X-Ray interaction in the diagnostic range are ______.

A

Compton scattering and photoelectric absorption

17
Q

Which X-Ray interaction generally involves ejection of an outer shell electron?

A

Compton scattering

18
Q

There is complete absorption of the incident diagnostic X-Ray photon causing ionization with ________.

A

photoelectric effect

19
Q

Image fog in diagnostic imaging is caused by

A

Compton scatter

20
Q

After photoelectric absorption, there will be ______.

A

a scattered electron

21
Q

A negative contrast agent is ____.

22
Q

The addition of scattered X-Rays to the image receptor______

A

degrades contrast

23
Q

The use of contrast agents increases the amount of __________.

A

Compton scatter
photoelectric absorption
differential absorption
(All of the above)

24
Q

X-Rays transmitted without interaction contribute to _______.

A

the radiographic image

25
Radiographic contrast is ________.
the difference in attenuation between adjacent areas
26
The beam exiting the patient is mostly ______.
high energy X-Rays
27
Radiographic contrast depends on ________.
kVp tissue thickness tissue density (all of the above)
28
Higher energy X-Ray beams have lower ______ than X-Ray beams with lower energy.
attenuation
29
Barium and iodine are good contrast agents because of their _________.
high atomic number
30
Only at the highest X-Ray energies, around 10 MeV, can ____ take place.
photodisintegration
31
About ____ of the incident beam from the X-Ray tube contributes to the finished image.
0.5%
32
Differential absorption is dependent on the ________.
kVp of the exposure. atomic number of the absorber. mass density of the absorber. (All of the above.)