Final Class Review

Question 1

How does the use of a small filament/focal spot affect the radiograph?

Answer 1

-sharper image

Question 2

two of the three factors that influence compton scatter production:

Answer 2

• high kvp
• large commination area
• compression

Question 3

how does collimating to a smaller area affect contrast?

Answer 3

• increase contrast

- decrease scatter

Question 4

Name two radiosensitive cells:

Answer 4

• Lymphocytes

- Sperm/egg

Question 5

Two factors that increase the probability that a photon will undergo a photoelectric absorption interaction.

Answer 5

Low KVP

High atomic number

Question 6

Dosimeter reports express occupationally exposed persons doses in ____ units.

Answer 6

REM

Question 7

Increasing OFD ____ detail sharpness.

Answer 7

decreases

Question 8

When collimating from a 14x17 area to an 8x10 area the mAs must:

Answer 8

increase by 50%

Question 9

Using oxidized developer ____ density and contrast.

Answer 9

decreases

Question 10

State two condition for using a bucky grid:

Answer 10

Greater than 10 cm

KVP higher than 60

Question 11

What is the purpose of using a bucky grid?

Answer 11

Reduce Compton Scatter

Question 12

One of the purposes of the fixer solution:

Answer 12

Remove the undeveloped/unexposed silver

To harden the gelatin emulsion

Question 13

Where should a radiation dosimeter be worn?

Answer 13

On the collar outside the lead apron

Question 14

To maintain radiographic density: if mAs is decreased by 50% the kVp should be:

Answer 14

increased by 15%

Question 15

This technical factor controls the quantity of x-rays in the beam:

Answer 15

mAs

Question 16

kVp controls this photographic property:

Answer 16

contrast

Question 17

Name three radiation protection devices:

Answer 17

Lead apron 
Gonad shield 
Filter
Collimator
Intensifying screen

Question 18

Name the crystals found in the film emulsion:

Answer 18

silver halide

Question 19

The developer solution converts silver halide to:

Answer 19

black metallic silver

Question 20

define linearity:

Answer 20

The ability to manipulate mA * time to get the same mAs

Question 21

State the charge that is on the focusing cup:

Answer 21

negative

Question 22

This type of ionizing radiation can be stopped by the out layers of the skin:

Answer 22

alpha particles

Question 23

State the two parts that make up the cathode:

Answer 23

focusing cup

filaments

Question 24

X-rays are produced by ____ current.

Answer 24

DC

Question 25

what does a rectifier do?

Answer 25

converts AC to DC current

Question 26

The anode side of the tube should be ____ when imagining an AP thoracic spine:

Answer 26

UP

Question 27

In the x-ray tube, electrons travel from ____ to the ____

Answer 27

cathode to the anode

Question 28

How often must lead walls be replaced?

Answer 28

never

Question 29

Assuming patient motions may be an issue: how should all mA and time settings be set?

Answer 29

highest mA lowest time

Question 30

The __ side of the image will exhibit the least radiographic density

Answer 30

anode

Question 31

As mAs increase, patient exposure:

Answer 31

increases

Question 32

How do u select the small filament on the console?

Answer 32

Select one of the low mA settings on our machine: pick either 25.75 or 150

Question 33

Describe a photon in terms of mass, charge and velocity:

Answer 33

No mass, no charge, speed of light

Question 34

What photographic property does mAs control?

Answer 34

Density

Question 35

The __ controls the wavelength of the x-rays:

Answer 35

kVp

Question 36

Compare the wavelengths of x-rays to radiowaves:

Answer 36

X-ray wavelengths are shorter

Question 37

How must mAs be adjusted to double radiographic density?

Answer 37

double mAs

Question 38

You experience a tube overload, what should be done to correct it?

Answer 38

decrease the mAs

Question 39

MAs can be rounded __ without a change in radiographic density.

Answer 39

30%

Question 40

State the formula for REM.

Answer 40

RAD x QF | RAD times the quality factor or the type of radiation one is exposed to

Question 41

What is the relationship between x-ray frequency and wavelength

Answer 41

inverse

Question 42

State the heat unit formula:

Answer 42

kVp x mAs

Question 43

Which x-ray production method is responsible for producing the majority of the x-rays in the beam?

Answer 43

Bremsstrahlung

Question 44

Optimum kVp for extremities under 10cm is in the ____ range.

Answer 44

50-60

Question 45

This type of rectification produces the highest energy of x-rays

Answer 45

high frequency

Question 46

Describe the bremsstrahlung x-ray production process

Answer 46

Electron is decelerated by the nuclear force field and changes directions. The change in kinetic energy is converted to EM energy.

Question 47

State the optimum kVp range for spine imaging

Answer 47

70-90

Question 48

Is optimum kVp higher for high frequency or full wave rectification?

Answer 48

full wave

Question 49

Define ALARA

Answer 49

Exposure as low as reasonably achievable

Question 50

__mRAD = 1 RAD

Answer 50

1,000

Question 51

Why does the path of film travel matter in automotive processing?

Answer 51

Chemical replenishment rates

Question 52

What is the only similarity between alpha, beta particles and x-ray?

Answer 52

They can all ionize atoms

Question 53

__ Characteristic x-rays of tungsten are useful

Answer 53

K

Question 54

State the SI unit for REM

Answer 54

Seivert

Question 55

Where are compensating filter placed?

Answer 55

Between the collimator and the patient

Question 56

What is the #1 enemy of detail sharpness?

Answer 56

motion

Question 57

This classical radiation unit describes radiation energy absorbed in matter

Answer 57

RAD

Question 58

What is the purpose of using compensating filters?

Answer 58

To produce a uniform radiographic density

Question 59

Why is the back of the cassette lined with lead?

Answer 59

To reduce backscatter radiation

Question 60

The x-ray tube target is made of:

Answer 60

tungsten

Question 61

Define radiographic density

Answer 61

Blackness in the image: mass per unit volume of black metallic silver

Question 62

Define ionize

Answer 62

The total removal of an electron from its orbit (around the nucleus)

Question 63

When is the x-ray exposure complete

Answer 63

When the light goes out