image production 4.2 110420

Question 1

Receptor exposure may be defined as

Answer 1

Dose area product

Question 2

The primary controlling factors of receptor exposure

Answer 2

mAs and SID

mAs controls electron flowing thru XR tube and striking anode

Question 3

Receptor exposure was formerly called

Answer 3

density

Question 4

The radiograph image is formed by

Answer 4

exit rays striking the image receptor

Question 5

The number of electrons boiled off the cathode and consequently the number of XRs produced are controlled by

Answer 5

mAs

Question 6

mAs directly control

Answer 6

The quantity of XRs produced at anode

Question 7

Visible differences in adjacent structures on a radiographic image describe

Answer 7

contrast resolution

Question 8

The primary controlling factor of contrast is

Answer 8

KVP and bit depth
KVP controls wavelength and penetrating ability of beam.
In digital imaging window width can be used to manipulate contrast

Question 9

Which of the following describes the relationship between mAs and receptor exposure

Answer 9

receptor exposure is directly proportional to mAs

Question 10

The relationship between KVP and receptor exposure may be described as

Answer 10

Direct, although not proportional

It is governed by 15% rule

Question 11

The active portion of a CR IP is

Answer 11

PSP

Question 12

The role of KVP in radiographic image production

Answer 12

1. As KVP is increased, penetrating ability of the XRs increase
2. As KVP is increased, more XRs exit the pt to strike the IR
3. As KVP increases, receptor exposure increases

Question 13

Which of the following governs the relationship between SID and receptor exposure

Answer 13

Inverse square law

Question 14

If SID is doubled, what may be said about receptor exposure

Answer 14

RE is reduced to 1/4

Question 15

If SID is reduced by one half, what must be done mAs to maintain a constant receptor exposure

Answer 15

Reduce mAs to 1/4 it

Question 16

Grey tones (high KVP)

Answer 16

long scale, low contrast

Question 17

Black and white

Answer 17

short scale, high contrast

Question 18

lower spatial reso

Answer 18

wide pixel pitch

Question 19

The variation of XR intensity along the longitudinal axis of the XR beam describes

Answer 19

anode heel effect

Question 20

XR tube angle

Answer 20

affects receptor exposure

Question 21

What kind of interactions contribute to differential absorption

Answer 21

Photoelectric interaction

Influenced by atomic number not atomic mass of anatomical structures

Question 22

What effect does beam restriction have on contrast

Answer 22

increases contrast bc of reduction in the number of Compton interactions that occur
Compton interactions produce scatter which causes contrast to decrease

Question 23

The adjustment in technical factors reqd when using beam restriction is

Answer 23

increase mAs to compensate for the number of rays removed from the primary beam

Question 24

What effect does the use of radiographic grids have on contrast

Answer 24

increases contrast by absorbing scatter radiation

Question 25

As the amount of beam filteration is increased

Answer 25

contrast decreases | Overall wavelength of beam is shorter resulting in lower contrast

Question 26

spatial resolution is

Answer 26

geometric representation of the part being radiographed | Controlled by SID, OID, focal spot size, ptixel pitch

Question 27

what SID, OID, focal spot size be for higher spatial reso

Answer 27

long SID, short OID, small focal spot

Question 28

Optimal spatial reso may be created usng which of the following factors

Answer 28

narrow pixel pitch

Question 29

Improper use of grids may result in an image artifcact known as

Answer 29

moire pattern

Question 30

Distortion may be described as

Answer 30

misrepresentation of an anatomic structure on the image

Question 31

Elongation and foreshortening are examples of

Answer 31

shape distortion

Question 32

single phase full wave rectification produce

Answer 32

100% ripple and pulsating DC with 120 pulse per sec

Question 33

3 phase 6 pulse full wave rectification produces

Answer 33

13% ripple DC

Question 34

3 phase 12 pulse full wave rectification produces

Answer 34

4% ripple DC

Question 35

The increase in average photon energy with 3 phase 6 pulse equipment compared to single phase

Answer 35

is 35% higher energy than single phase | KVP X MAS X 1.35= heat calculations

Question 36

The increase in average photon energy with 3 phase 12 pulse equipment compared to single phase

Answer 36

is 41% higher energy than single phase | KVP X MAS X 1.41= heat calculations

Question 37

single phase equipment average photon energy is

Answer 37

kvp x mas= heat calculations

Question 38

to get more black and white on image what kind of kvp do you use

Answer 38

lower kvp | = higher contrast = short scale

Question 39

to get more shades of grey what kind of kvp do you use

Answer 39

high kvp | = low contrast = long scale

Question 40

different types of interactions with incident e

Answer 40

characteristic or brem

Question 41

different types of interactions with patient

Answer 41

compton or photoelectric