X-ray Quality and Quantity

Question 1

penetrability

Answer 1

ability of x-rays to penetrate deeper in tissue

Question 2

x-rays that have high penetrability are termed:

Answer 2

high-quality x-rays

Question 3

factors affecting x-ray beam quality:

Answer 3

kVp
filtration
target material
generator type

Question 4

kVp is:

Answer 4

the max voltage applied to the tube

Question 5

increasing kVp:

Answer 5

increases the kinetic energy of the electrons therefore creating more photons

Question 6

required total filtration:

Answer 6

2.5 mm Al

Question 7

collimator and an additional filter (added) provides how much filtration?

Answer 7

2.0 mm Al

Question 8

inherent filtration provides
how much filtration?

Answer 8

0.5 mm Al

Question 9

what is the primary purpose of adding filtration?

Answer 9

remove low energy photons from the beam

Question 10

increasing filtration:

Answer 10

increases the average quality of the beam

Question 11

what does increasing filtration create?

Answer 11

more monoenergetic and harder average beam

Question 12

target material affects both:

Answer 12

the number and average quality of photons produced

Question 13

higher energy x-rays increase in number to a ________________ than low-energy photons

Answer 13

greater extent

Question 14

what will shift the effective energy of the x-ray spectrum?

Answer 14

target material

Question 15

what doesn’t target material shift?

Answer 15

the position of spectrum along the x-axis

Question 16

half value layer (HVL)

Answer 16

thickness of a material needed to cut the intensity in half

Question 17

as beam quality goes up,

Answer 17

so does the HVL

Question 18

the HVL measures the quality of

Answer 18

the x-ray beam

Question 19

what happens if a HVL isn’t enough for a certain kVp amount?

Answer 19

additional sheets of filtration are added

Question 20

as more filtration is added, what happens to the HVL?

Answer 20

HVL increases in order to reduce the intensity in half

Question 21

factors affecting quantity:

Answer 21

mA
kvp
exposure time
filtration

Question 22

quantity is directly proportional to:

Answer 22

mA

Question 23

when mA is doubled:

Answer 23

the electrons are doubled, therefore the number of x-rays emitted is doubled

Question 24

when exposure time is doubled,

Answer 24

the number of x-rays emitted is doubled

Question 25

increasing filtration will:

Answer 25

decrease the quantity of the beam

Question 26

higher kVp =

Answer 26

higher quantity due to more electron attraction, resulting in greater photon amount (quantity)

Question 27

saturation current:

Answer 27

current at its max value because all electrons have been used up

Question 28

doubling kvp increases intensity by a factor of:

Answer 28

4!!

Question 29

the higher the Z number of a material:

Answer 29

the higher the quantity of x-rays

Question 30

the greater the anode angle, the lesser the:

Answer 30

anode heel effect

Question 31

the greater the target angle,

Answer 31

the greater the quantity

Question 32

less anode heel effect =

Answer 32

greater quantity

Question 33

a more powerful generator will:

Answer 33

produce a higher quantity of x-rays

Question 34

variable-kVp techniques

Answer 34

uses a fixed mAs value and a kVp that varies according to the thickness of the anatomical part produces shorter scale images

Question 35

fixed-kVp technique

Answer 35

kVp is selected as the optimum required for penetration of the part. The mAs is then adjusted according to thickness produces longer gray scale images

Question 36

mA

Answer 36

heat (temp) of the filament

Question 37

unit of measure for tube current

Answer 37

mA

Question 38

x-ray production require greater quantities of what?

Answer 38

voltage

Question 39

longer exposure time =

Answer 39

more x-rays produced

Question 40

SID:

Answer 40

distance from the Actual focal spot to the IR

Question 41

what is the best protection from radiation?

Answer 41

distance

Question 42

required HVL at 130 kVp

Answer 42

3.5 mm Al

Question 43

two factors that determine an x-ray photon's keV

Answer 43

kVp proximity to nucleus

Question 44

what's the relationship between anode angle and beam quantity?

Answer 44

direct (more photons can escape anode)

Question 45

what is the controlling factor for beam quality?

Answer 45

kVp

Question 46

the HVL test is a measure of ________ that uses ________ as a unit of measurement

Answer 46

quality, quantity

Question 47

why is kVp not used to make adjustments in beam quantity?

Answer 47

changes in kVp affect beam quality

Question 48

what characteristic makes a target material an "efficient" target, when it comes to quantity?

Answer 48

high Z number

Question 49

the required HVL at 90 kVp is:

Answer 49

2.5 mm Al

Question 50

the prime exposure factor that affects both quality and quantity (described as the "big wrench")

Answer 50

kVp

Question 51

increasing SID has what effect on beam quality?

Answer 51

none (moving the tube doesn't affect the energy)

Question 52

changing a 50 kVp setting to a 100 kVp (doubling kVp) will have what effect on beam quantity?

Answer 52

increases by 4x

Question 53

who is responsible for performing an annual HVL test?

Answer 53

physicist

Question 54

increasing filtration has what effect on HVL?

Answer 54

increase

Question 55

x-ray beam quality and differential absorption share what type of relationship?

Answer 55

indirect

Question 56

x-ray beam average quality improves by what?

Answer 56

filtration

Question 57

what is the difference between intensity and quantity?

Answer 57

intensity is the number of photons that land in a certain area due to SID quantity is the number of x-rays exiting the tube

Question 58

Law of Reciprocity:

Answer 58

exposure will be the same if mAs is constant mAs = mAs = mAs