Chapt Four Flashcards Preview

Radiography > Chapt Four > Flashcards

Flashcards in Chapt Four Deck (48)
Loading flashcards...
1

~Quality
~Penetration
~Energy

kV

2

Milliamperage and exposure time have an ______ partly relationship when maintaining the same mAs

Inverse

3

The minimum of change needed for a correct for a density error is determined by multiplying or dividing mAs by ______

2

4

If a screen is 2xs fast then the mAs should be cut _____

1/2

5

Making a visible change in density requires a minimum change in mAs by approx __1__.

30%

6

What effects density because it alters amount and penetrating ability of the beam

kVp

7

Maintaining or adjusting density can be accomplished with kV by using what rule?

15% Rule

8

15% Rule states
A: changing kVp by 15% will have the same affects as __1__ or cutting it __2__

B: if you want to maintain density and you add 15% kVp, you must cut mAs ________.

C: if you subtract 15% kVp, you must _____ mAs

D: below 90 kV, work in factors of ______.

E: above the 90 kV work in factors of ______

A: 1-Doubling
2-in 1/2

B: half

C: double

D: 10
E: 15

9

As _______ is increased, the quality of xray production is raised, but the energy of the photons is not affected.

mA

10

In order to see a visible change in radiographic density, the mAs should be increased or deceased by ___________.

30%

11

The law that explains the relationship between SID and mAs is ________

Inverse Square Law

12

The amount of darkening/blackness which is seen on a radiograph is a measure of radiograph.

Density

13

A radiograph is taken showing insufficient penetration. This could be corrected by _________

Increasing the kV

14

The quality of an X-ray beam is primarily controlled by the _________.

kV

15

A radiograph is produced which shows a large amount of scatter radiation. One method that can be employed to decrease this scatter is:

Lower the kV

16

The use of low kV photons results in a radiograph with a small number of widely varying density values termed:

Short scale of contrast

17

The mAs values for an exposure will primarily effect the following:

Pt. dose

18

An increase in mAs during an exposure with no other changes made will increase the:

Number of photons produced

19

Hardest to easiest to penetrate

Teeth, bone, muscle, fat, gas

20

The major function of the grid generally utilized in an X-ray department serves to:

Reduce the scatter reaching the IR

21

Which of the following would produce a radiograph with the longest scale of contrast?

A. 50 mA, 1 sec, 70kV

B. 100 mA, .5 sec, 80 kV

C. 200 mA, 1/4 sec, 90 kV

C

22

Which is not used as contrast?
Air, Saline, Barium, or Iodine?

Saline

23

Which would produce a longer scale of contrast, increasing kV or decreasing kV?

Increasing kV

24

The greater the atomic number of the part, the ______ the resulting density on the radiograph.

Less

25

If the distance tweet the tube and the pt. is cut in half and no adjustments we made to the technique, what happens to pt. dose?

It increases by 4 times

26

An example of an inorganic interspacer

Aluminum

27

Grids doesn't __1__ production of scatter. It __2__ overall quality of image.

1. Decrease

2. Improves

28

SCATTER IS ______

DENSITY

29

Grid ratio=

Height of Pb strips/distance between Pb strips

30

The higher the grid ratio, the more ________ the grid

Restrictive