Rad Physics - Ch 6 - Review questions

If increasing exposure by 15%, to maintain the IR you will need to _____ the mAs.

Half

If decreasing exposure by 15%, to maintain the IR you will need to ______ the mAs by 2.

Multiply

An increase of 15% =

X 1.15

A decrease of 15% =

X 0.85

Useful characteristic x-rays are produced in tungsten:

By removal of a k-shell electron.

What is produced when the projectile electron excites an outer-shell electron?

Heat

When energy of characteristic x-rays increase with increasing:

Atomic number of target material.

When a tungsten-targeted x-ray tube is operated at 68 kVp:

K-shell characteristic x-rays cannot be produced.

When a Bremsstrahlung x-ray is produced:

A projectile electron loses energy.

Normally, the x-ray emission spectrum contains:

Both characteristic and bremsstrahlung x-rays.

The characteristic x-ray emission spectrum principally depends on which of the following?

Target Material.

The x-ray emission spectrum represents:

X-rays emitted from the x-ray tube.

A filament eletron interacts with an outer shell electron of a tungsten atom but does not remove it. What is produced?

Heat

A filament electron enters a tungsten atom with an energy of 70 kVp. It interacts first with an L-shell electron, when with a K-shell electron. Which of the following is produced?

A) A characteristic interaction

B) A bremsstrahlung interaction

C) Heat

Both A and C

What is the keV energy of an x-ray photon produced when an O-shell electron fills a K-shell vacancy?

69.42

What is the keV energy of an x-ray photon produced when an L-shell electron fills a K-shell vacancy?

57.40

What is the energy level of an x-ray produced if the incoming energy of the incident electron is 75 keV and the outgoing energy of the same electron is 50 keV?

25

What is the energy of an x-ray produced if the incoming energy of the incident electron is 90 keV and the outgoing energy of the same electron is 60 keV?

30

60 keV is increased by 15%. What is the kVp?

69

If the kVp is increased by 15% and you need to maintain exposure to the IR, the original mAs of 30 will now become ______ mAs.

15

90 kVp is increased by 15%. What is the new kVp?

104

If the kVp is decreased by 15%, the original mAs of 80 should be changed to _____ mAs to maintain exposure to the IR.

160

What describes the penetrating power of the x-ray beam?

Beam quality

Whar describes the total number of x-ray photons in the x-ray beam?

Beam Quantity

What is the term used to describe the process of outer-shell electrons filling inner-shell vacancies?

Characteristic cascade

The contunuous emission spectrum graphically demonstrates:

Brems interactions

The discrete emission spectrum graphically demonstrates:

Characteristic interactions

What is used to measure beam quality?

Half-value layer

Which of the following terms best describes the x-ray beam upon exiting the collimator and exposing the patient?

Primary beam

Which of the following terms best describes the x-ray beam that remains after interaction with the patient and exits the patient to expose the image receptor?

Remnant beam

The term used to describe x-ray photons exiting the patient without interacting with anatomic structures is?

Transmission

The term used to describe photons that have lost energy have been redirected after interacting with anatomic structures:

Scatter

For a characteristic interaction, what does the filament electron interact with?

Target electron

For a Brems interaction, what does the filament electron interact with?

Target nucleus

The keV of the filament electron must be _______ the target electron binding energy to remove a target electron.

Greater than

If a filament electron passes close to the nucleus, what results?

High-energy photon

The tube head assembly that absorbs photons is known as:

Inherent filtration

A material that is added to the tube head assembly specifically to absorb photons is known as:

Added filtration

Which of the following affect beam quantity?

All of the above

Which of the following affect beam quality?

A) kVp

B)Filtration

C) Distance

D) mAs

Both A and B

Beam Quantity:

Increasing mAs…

Increases quantity

Beam Quantity:

Decrease kVp…

Decreases Quantity

Beam Quantity:

Decrease distance…

Increases quantity

Beam Quantity:

Decrease filtration…

Increases quantity

Beam quality:

Increase kVp…

Increases quality

Beam quality:

Increase filtration…

Increases quality

Beam quality:

Increase mAs…

No change

Beam quality:

Increase distance…

No Change

Match the interaction type with the following scenarios:

An incident electron removes a K-Shell electron, and an M-Shell Electron fills the vacancy.

Characteristic Interaction

Match the interaction type with the following scenarios:

An incident electron removes an L-Shell electron, and an O-Shell electron fills the vacancy.

Characteristic Intraction

Match the interaction type with the following scenarios:

An incident electron enters a tungsten atom with an energy of 120 keV and leaves the atom with an energy of 40 keV.

Brems Interaction

Match the interaction type with the following scenarios:

An incident electron with 90 keV strikes a K-shell electron of a tungsten atom.

Characteristic Interaction

How is beam quality affected if filtration is decresed?

Beam quantity increases.

How is beam quantity affected if kVp is increased?

Beam quantity increases.

What is the primary controller of beam quantity?

mAs

What is the primary controller of beam quality?

kVp

How is beam quantity affected if mAs is decreased?

Beam quantity decreases.