Image Production 2

Question 1

What is the focusing cup made of

Answer 1

Molybdenum or nickle

Question 2

Focusing cup

Answer 2

• negatively charged

- controls the path of electrons from cathode to anode

Question 3

Line focus principle

Answer 3

• The effective focal spot is smaller than the actual focal spot
• angled design of the anode

Question 4

What gets projected down to the pt

Answer 4

Effective focal spot

Question 5

Smaller Effective focal spot ______ spatial resolution

Answer 5

Greater

Question 6

Which will have the greatest heat capacity

Answer 6

Large focal spot with smallest target angle

Ex) 1.0 with 10 degree

Question 7

Which target degree angle will provide greatest spatial resolution

Answer 7

• pick out smallest angle #*
  1) 7 degrees (CORRECT)
  2) 11 degrees
  3) 15 degrees
  4) 20 degrees

Question 8

Anode target material

Answer 8

-tungsten (high melting point, high atomic number, ability to dissipate heat)

Question 9

Selecting mA determines the number of electrons free around what

Answer 9

Filament

Question 10

Induction motor (stator windings and rotor)

Answer 10

• operates rotor that spins anode during an exposure
• engaging rotor switch fires the stator in a circular motion around the outside of the tube resulting in a circular movement of the rotor within the tube

Question 11

Xray beams are produced how

Answer 11

Isotropically (equal intensity in all directions)

Question 12

Radiation emitted through the metal protective housing should not exceed what

Answer 12

1 mGy/hr at 1 meter

Or 100 mR/hr at 1 meter

Question 13

Insulating oil

Answer 13

• Located outside glass envelope but inside metal protective housing
• assists in cooling xray tube
• contributes to inherent filtration

Question 14

Filtration

Answer 14

Added + inherent = total

Question 15

Back up timer

Answer 15

• Determines max length of exposure time for AEC exposure

- set at 150% of the anticipated manual exposure time

Question 16

What is the purpose of using back up timer when using a AEC device

Answer 16

To protect pt if AEC beam fails to terminate exposure

Question 17

Minimum response time (MRT)

Answer 17

time it takes for a system to respond and send the signal to terminate the exposure

Question 18

Ohm’s law

Answer 18

V (voltage or electric potential) = I (current measured in Amps) x R (resistance measured in ohms)

Question 19

Heat unit for single phase (1/2 and full wave)

Answer 19

1.0

Question 20

Heat unit for three phase 6 pulse

Answer 20

1.35

Question 21

Heat unit for three phase 12 pulse

Answer 21

1.41

Question 22

Heat unit for high frequency

Answer 22

1.61

Question 23

Parallel circuit

Answer 23

Find lowest value and divide by 2
Ex) 5,10,15,20
5/2= 2.5

Question 24

Transformers operate on the principle of electromagnetic induction and require what to operate

Answer 24

Alternating current

Question 25

As The number of turns of a conductor material increases ____ electromotive force is produced

Answer 25

Greater

Question 26

Turns ratio

Answer 26

Ts/Tp

Question 27

Located on primary low volatility side

Answer 27

1) AC supply 2) master wall switch 3) fuses 4) line voltage meter 5) autotransformer 6) line voltage compensator 7) pre reading kVp meter 8) exposure switch 9) exposure timer

Question 28

Source for kV

Answer 28

Autotransformer (self induction)

Question 29

When/where does voltage become kilovoltage

Answer 29

At step up transformer (operates on principle of electromagnetic mutual induction)

Question 30

Filament transformer

Answer 30

- aka low voltage or step-down transformer - located within low voltage filament circuit - electromagnetic mutual induction

Question 31

What is an example of a precision (variable) resistor

Answer 31

mA station

Question 32

Types of exposure timers

Answer 32

1) mechanical 2) synchronous (capable of exposure times in multiples of 60 3) electronic (accurate) 4) mAs 5) impulse 6) AEC

Question 33

Located within filament low voltage circuit

Answer 33

1) mA selector | 2) focal spot selector

Question 34

Located in secondary or high voltage circuit

Answer 34

1) mA meter | 2) rectifiers

Question 35

High frequency

Answer 35

- results in higher xray quality and quantity | - voltage ripple is 1% since voltage waveform is nearly constant

Question 36

ADC

Answer 36

Performs the sampling and quantization of data

Question 37

Rescaling

Answer 37

Processing technique used to correct for over or under exposure

Question 38

Histogram

Answer 38

Present a graphical representation of optimal densities during an exposure and recognition of exposure data requires processing only optimal receptor exposure exposures

Question 39

Values of interest

Answer 39

The digital data set of information that is arranged into a histogram distribution

Question 40

LUT is used to as a reference to evaluate what

Answer 40

The raw information and to correct the luminance values

Question 41

Edge enhancement

Answer 41

Results when the signal average includes fewer pixels in the neighborhood. Used when fine details in an image or shown with some blur

Question 42

The ability of a system to provide contrast enhancement

Answer 42

Equalization

Question 43

Another name for smoothing

Answer 43

Low pass filter

Question 44

Occurs by averaging all pixels frequency with surrounding pixel values to remove image noise

Answer 44

Smoothing

Question 45

Describes the contribution of all system components towards total resolution

Answer 45

Modulation transfer function | -resolution is best as MTF value approaches 1

Question 46

Magnification factor=

Answer 46

Image size/object size

Question 47

Equalization

Answer 47

Makes light areas darker and dark areas lighter