Deck 2: The X-Ray Beam

Question 1

Which of the following could be defined as the production of an x-ray photon by the electrostatic attraction between the incident electron and the nucleus of the tungsten atom?

A) Photoelectric interaction
B) Bremmstrahlung interaction
C) Characteristic interaction
D) Pair production interaction

Answer 1

Bremmstrahlung interaction

Question 2

The focusing cup:

A) Surrounds the anode
B) Has a positive charge
C) Has a negative charge
D) Focuses the x-ray beam

Answer 2

Has a negative charge

Question 3

What is the base material of the anode disc?

A) Molybdenum
B) Tungsten
C) Rhenium
D) Beryllium

Answer 3

Molybdenum

Question 4

Which of the following could be defined as the production of an x-ray photon by a collision between the incident electron and a K-shell electron of the tungsten atom?

A) Photoelectric interaction
B) Bremsstrahlung interaction
C) Characteristic interaction
D) Pair production interaction

Question 5

mA is a measure of _____ that flows from cathode to anode.

A) Filament current
B) Tube current
C) Space charge
D) Thermionic emission

Question 6

The amount the voltage varies during an x-ray exposure is known as:

A) kVp
B) Voltage ripple
C) mA
D) Tube current

Question 7

The positive side of the x-ray tube is the:

A) Anode
B) Cathode
C) Window
D) Stream of electrons

Question 8

What is the name of the device in a rotating anode x-ray tube that turns the rotor?

A) Stator
B) Rotor
C) Focusing cup
D) Rheostat

Question 9

Increasing the kVp will do which of the following?

A) Decrease the tube current
B) Increase the speed of the electrons
C) Increase the penetrability of the beam
D) B and C

Question 10

What is an acceptable level of leakage from the tube housing?

A) 100 mR per hour, measured 6 feet away
B) 10 mR per hour, measured 1 foot away
C) 1000 R per hour, measured at a distance of 4 meters
D) 100 mR per hour, measured at a distance of 1 meter

Question 11

The filament is made of:

A) Tungsten
B) Rhenium
C) Molybdenum
D) Lead

Question 12

The actual flow of electrons from cathode to anode within the x-ray tube is known as:

A) Tube current
B) Filament current
C) Anode current
D) A and C

Question 13

What focal spot size is measured directly under the anode target?

A) Actual focal spot
B) Target focal spot
C) Filament focal spot
D) Effective focal spot

Question 14

The maximum speed the rotating anode will typically achieve is _____ rpm.

A) 3200
B) 5000
C) 10,000
D) 20,000

Question 15

What is the name of the exact area on the anode that is struck by the electron stream?

A) Focal spot
B) Focal point
C) Focal range
D) Any of the above

Question 16

Effective compensation for the anode heel effect would involve positioning:

A) the thinnest portion of the part under the anode
B) The thickest portion of the part under the anode
C) The thinnest portion of the part under the cathode
D) B and C

Question 17

The _____ is the portion of the x-ray tube that contains the filament.

A) Cathode
B) Anode
C) Rotor
D) Rotating disk

Question 18

Filtration of the x-ray beam results in:

A) Increased beam quantity
B) Increased beam quality
C) Lower average energy photons
D) B and C

Question 19

_____ is the phenomenon that occurs around the filament during thermionic emission and prevents the further escape of electrons from the filament.

A) Saturation current
B) Space charge effect
C) mA rectification
D) Line focus principle

Question 20

_____ is the boiling off of electrons from the filament when current is applied.

A) Saturation emission
B) Thermionic emission
C) Filament transport
D) Proton emission

Question 21

The device that nearly surrounds the filament is the:

A) Rotor
B) Focusing cup
C) Stator
D) Anode

Question 22

In order to produce x-rays, electrons must be:

A) Suddenly decelerated
B) Accelerated
C) Liberated from the cathode filament
D) All of the above

Question 23

The part of the x-ray tube that is connected to the target and causes it to turn is the:

A) Filament
B) Rotor
C) Stator
D) Base

Question 24

The rotating target track is primarily made of:

A) Rhenium
B) Nickel
C) Tungsten
D) Copper

Question 25

The amount of filtration required to reduce the exposure of the beam to half of its original intensity is defined as:

A) Wedge filtration
B) HVL
C) mAs compensator
D) mA linearity

Question 26

_________________ envelopes are more commonly used in today's x-ray tubes.

A) Glass
B) Paper
C) Metal
D) Lead

Question 27

As compared to glass, which of the following is an advantage to having a metal envelope x-ray tube?

A) Decrease in off-focus radiation
B) Increase in off-focus radiation
C) Increased deposits of tungsten on the inside surface of the envelope
D) A and C

Question 28

Which of the following is not classified as inherent filtration?

A) The oil in the transformer
B) The collimator mirror
C) The tube envelope
D) The oil surrounding the tube

Question 29

Which of the following types of filtration produce a more uniform exposure to the image receptor?

A) Compensating
B) Half-value
C) Inherent
D) Spatial

Question 30

Diagnostic x-ray exposures range from:

A) 15 to 40 kVp
B) 20 to 65 kVp
C) 30 to 150 kVp
D) 60 to 225 kVp

Question 31

With a standard x-ray tube, ______________% of the x-ray beam produced with 90 kVp is the result of bremsstrahlung interactions.

A) 0
B) 15
C) 85
D) 100

Question 32

With a standard x-ray tube, ______________% of the x-ray beam produced with 65 kVp is the result of bremsstrahlung interactions.

A) 0
B) 15
C) 85
D) 100

Question 33

With a standard x-ray tube, ______________% of the x-ray beam produced with 65 kVp is the result of characteristic interactions.

A) 0
B) 15
C) 85
D) 100

Question 34

With a standard x-ray tube, ______________% of the x-ray beam produced with 90 kVp is the result of characteristic interactions.

A) 0
B) 15
C) 85
D) 100

Question 35

The advantage to having a focal track is that:

A) The focal spot will be smaller.
B) The focal spot will be larger.
C) Lower exposure factors can be used.
D) Higher exposure factors can be used.

Question 36

A dual-focus tube has two:

A) Cathode filaments
B) Anodes
C) Tubes
D) None of the above

Question 37

The target angle of rotating targets typically ranges from:

A) 1 to 5°
B) 5 to 20°
C) 30 to 50°
D) 50 to 70°

Question 38

Inside the x-ray tube envelope you will find:

A) Oil
B) Air
C) a and b
D) None of the above

Question 39

Tungsten has a ________ atomic number and a _________ melting point.

A) Low; low
B) Low; high
C) High; low
D) High; high

Question 40

The speed the electrons inside the x-ray tube travel is:

A) The speed of light
B) Approximately one half the speed of light
C) Dependent on the mAs set
D) Dependent on the exposure time set.

Question 41

The larger the anode angle, the:

A) Larger the actual focal spot
B) Smaller the actual focal spot
C) Larger the effective focal spot
D) Smaller the effective focal spot

Question 42

Due to the anode heel effect, the differences in intensities between the ends of the x-ray field can be as much as:

A) 10%
B) 25%
C) 45%
D) 60%

Question 43

Setting identical exposure factors, which type of x-ray unit will produce the greatest heat?

A) Single phase
B) Double phase
C) Three phase
D) High frequency

Question 44

When an electron from the L-shell of the tungsten atom is ejected from its orbit by a projectile electron, high energy x-ray photons are produced.

Question 45

Electrons can flow from cathode to anode or from anode to cathode during the x-ray exposure.

Question 46

When making an exposure, which of the following does not occur when just the rotor, or prep button, is activated?

A) The anode begins to rotate.
B) Voltage is applied across the tube.
C) Current is applied to the filament.
D) A space charge is created.

Question 47

How many HU are produced when using a single phase x-ray unit, 400 mA, 200 ms, and 70 kVp?

A) 5600 HU
B) 7560 HU
C) 5,600,000 HU
D) 7,560,000 HU

Question 48

Filament current is approximately:

A) 0.5 to 2 milliamperes
B) 3 to 5 milliamperes
C) 0.5 to 2 amperes
D) 3 to 5 amperes

Question 49

The quality of the x-ray beam indicates:

A) The number of photons
B) The ability of the photons to penetrate
C) The quantity of radiation
D) Whether or not the photons were made well

Question 50

Doubling mA results in:

A) Doubling the tube current
B) Doubling the quantity of x-ray photons
C) Doubling the thermionic emission
D) All of the above

Question 51

The x-ray beam produced with 120 kVp will consist primarily of x-rays produced by bremsstrahlung interactions.

Question 52

The highest energy x-ray photons produced with a 100 kVp exposure will be:

A) 50 keV
B) 75 keV
C) 100 keV
D) 125 keV

Question 53

X-ray photon energy is measured in:

A) kVp
B) mA
C) Angstroms
D) keV

Question 54

Added tube filtration is typically made of:

A) Lead
B) Tungsten
C) Glass
D) Aluminum

Question 55

How much is the mAs when 400 mA and 100 ms are used?

A) 4 mAs
B) 40 mAs
C) 400 mAs
D) 4000 mAs

Question 56

During x-ray production, the energy of the moving electrons is converted to:

A) Kinetic energy
B) Thermal energy
C) Electromagnetic energy
D) B and C

Question 57

In order to produce 12 mAs, how long should the exposure time be when using 600 mA?

A) 0.002 s
B) 0.02 s
C) 0.2 s
D) 2 s

Question 58

X-ray tubes operating above 70 kVp must have total filtration of at least _________ of aluminum, or its equivalent.

A) 0.5 mm
B) 1 mm
C) 2 mm
D) 2.5 mm

Question 59

Decreasing the exposure time results in:

A) Fewer x-ray photons
B) More x-ray photons
C) Higher photon energy
D) Lower photon energy