Ch3 Flashcards

1
Q
  • Incoming x-ray
    photon interacts with
    a loosely bound outer
    (or middle) electron of
    an atom

• The incoming x-ray
photon surrenders a
portion of its energy,
ionizing the atom.

A

Comptom scatter

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2
Q

Incoming x-ray photon interacts with the electric field surrounding the
nucleus of an atom of irradiation tissue and disappears.
• The energy of the photon is absorbed and transformed into a
negatron and a positron

A

Pair Production

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3
Q

An interaction that
occurs at more than 10 MeV in
high-energy radiation therapy
treatment machines

A

Photodisintegration

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4
Q

Occurs at an energy level of at least 1.022 million electron volts (MeV).
• Beyond diagnostic energy range.

A

Pair Production

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5
Q

Incoming x-ray photons the interacts a loosely bound outer electron of an atom

  • Incoming x-ray photon surrenders a portion of his energy ionizing the atom
A

Compton scatter

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6
Q

Structures are similar in Atomicnumber z number ) and mass Must be distinguished by the use of

A

Contrast media

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7
Q

Barium iodine Bright/white

A

Positive contrast medium

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8
Q

Air dark/black

A

Negative contrast medium

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9
Q

The greater the difference in the amount of Photoelectric absorption the greater the

A

Contrast

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10
Q

As the absorption increases so does the potential…

A

Biologic damages

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11
Q

Less attenuation equals

A

Darker image

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12
Q

Image must have a significant amount of_____ In density to be clearly visualize

A

Variations

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13
Q

Atomic number for compact bone

A

13.8

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14
Q

Atomic number for soft tissue

A

7.4

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15
Q

Less density tissue less attenuation

Dense tissue more attenuation

These factors are known as

A

Influence attenuation

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16
Q

Occurrence of photoelectric absorption depends on

A

Energy E

Atomic number Z 

17
Q

Absorption increase ….. what happens to E and Z

A

Energy Incident photons decreases

Z of irritated out of increases

18
Q

Discovered by Pierre Victor Auger in 1925
> Produces an Auger electron
> Is a radiationless effect

A

Augar effect

19
Q

By-products of Photoelectric Absorption

A

Photoelectron and characteristic x-ray photons

20
Q

Interaction between x-ray photons and inner shell electrons

A

Photo electric absorption

21
Q

Diagnostic energy ranges  23 to 150 kvp

most important mode of interaction
between x-ray photons and the atoms

A

Photoelectron Absorption

22
Q

(aka fluorescent radiation)
(the remainder of the released energy which is so low it will be absorbed by the body)

A

Characteristic photon

23
Q

Interaction of photons in biologic matter is

A

Random

24
Q

Photons that undergo either absorption or scatter does not strike the image reception

A

Attenuation

25
Q

Photons that strike the image receptor are transmitted

A

Transmission

26
Q

Some primary photons will transverse the patient without interacting and reaching the image receptor

A

Direct transmission

27
Q

Other primary photons can’t undergo Compton or coherent interactions as a result may be scattered or deflected with a potential loss of energy

A

Indirect transmission

28
Q

x-ray photons that interact with the
atoms of a patient such that they give up all of
their energy and cease to exist

A

Absorption

29
Q

x-ray photons that interact with the
atoms of the patient, but only surrender part of their energy.

A

Scatter

30
Q

A diagnostic x-ray beam is produced when a stream of very energetic electrons bombards a positively
charged target in a highly evacuated glass tube.

A

Primary radiation

31
Q

Target (anode) composition used

A

Tungsten (a metal)
> Tungsten rhenium (a metal alloy)

32
Q

• The amount of energy per unit mass is).

A

absorbed dose

33
Q

energy level of photons in the x-ray beam, equal to the highest voltage established across the x-ray tube.

A

Kvp

34
Q

electron tube current and the amount of time in seconds that the x-ray
tube is activated.

A

Mas