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Flashcards in Plus minus chart Deck (101)
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1

What is the degree of blackening?

Density

2

What is the number of different shades of gray?

contrast resolution

3

What is the misrepresentation of size or shape of an object?

Distortion

4

What is the sharpness of structural lines?

recorded detail

5

What is the ability to image small parts?

spatial resolution

6

Distortion is controlled by what?

distance (SID)/angle of tube

7

Recorded detail is affected by?

SID, OID, Patient thickness

8

Distortion and recorded detail are related how?

inversely- when one increases/decreases opposite happens to the other

9

What is mAs?

the number of xrays

10

If mAs increases what happens to density?

increases (it is proportional)

11

If mAs increases what happens to patient dose?

patient dose increases because the amount of xrays going to the patient is higher

12

If mAs increases what happens to contrast?

no effect

13

If mAs increases what happens to distortion?

no effect because there is no change in distance or angle on tube

14

If mAs increases what happens to recorded detail/spatial res?

no effect (ex: sign on road at night its still there just gets darker)

15

If time (exposure time) increases what happens to density?

increases because image gets darker as exposure increases

16

If time (exposure time) increases what happens to contrast?

no effect

17

If time (exposure time) increases what happens to distortion?

no effect

18

If time (exposure time) increases what happens to recorded detail/spatial res?

decreases, expose longer= more time for patient to move= image gets blurry

19

If time (exposure time) increases what happens to patient dose?

increases

20

If kVp increases what happens to density?

increases, if kvp increases mas is halved if kvp decreases mas is doubled (15% rule)

21

If kVp increases what happens to contrast?

Decreases

22

If kVp increases what happens to patient dose?

decreases, if kvp increases there is more penetrability = less patient dose, if kvp decreases there is less penetrability= more patient dose

23

If kVp increases what happens to distortion?

no effect

24

If kVp increases what happens to recorded detail/spatial res?

no effect (image is still recorded doesn't matter if we see it because its still there)

25

What controlls kVp?

contrast/scatter/penetrability

26

High kvp=_____ scale

short

27

Low kvp=____ scale

long

28

If SID increases what happens to density?

decreases (less beam at the IR)

29

If SID increases what happens to contrast?

no effect

30

If SID increases what happens to patient dose?

decreases (the greater the SID the less dose)