Rad Physics Exam 3

Front 1

The most difficult grid to use is?

Back 1

Cross hatched

Front 2

A grid is used to improve?

Back 2

Radiographic contrast

Front 3

A grid absorbs?

Back 3

Scatter Radiation

Front 4

As KVP increases?

Back 4

- Contrast increases

- scatter increases

- image receptor exposure increases.

Front 5

As a general rule, a grid is employed when the body part thickness exceeds ____ cm.

Back 5

10

Front 6

As a general rule, a grid is employed when the KVP exceeds?

Back 6

70

Front 7

Which statement about grid is incorrect?

Back 7

A grid is a series of radiolucent strips that alternate with radiopaque interspace strips.

Front 8

The ratio of the height of the lead strips to the distance between the lead strips is the grid?

Back 8

Ratio

Front 9

Which grid would most effectively reduce scatter?

Back 9

16:1

Front 10

What is the typical k factor rating for grids in use today?

Back 10

1.5-3.5

Front 11

As the lead content of a grid increases?

Back 11

The ability of the grid to remove scatter increases.

Front 12

For a grid o be properly focused, the X-ray tube must be located along the _____ line.

Back 12

Divergence

Front 13

When establishing a technique chart, the first step involves?

Back 13

Producing a phantom image.

Front 14

A device that moves the grid during a radiographic exposure is called a?

Back 14

Potter-bucky diaphragm

Front 15

A grid is constructed with ___ strips and _____ interspace material.

Back 15

Radiopaque, radiolucent

Front 16

Gris are designed to remove scatter x-rays before they reach?

Back 16

The image receptor

Front 17

The amount of scatter absorption in a grid depends on?

Back 17

- the angle of the scattered photon.

- the height of the grid strips.

- the width of the interspace material

Front 18

What is the formula for grid ratio?

Back 18

H/d

Front 19

What is the grid ratio of a grid with 3-mm height, 0.025 - mm thick lead grid strips, and 0.3 mm thick interspace material?

Back 19

10:1

Front 20

A technologist must avoid the error of using a ____ grid either off-focus or upside down.

Back 20

Focused

Front 21

A high frequency grid is designed to be used with?

Back 21

Digital radiography

Front 22

A radiograph is made at 86 kvp and 25 mas w/o a grid. If an 8:1 grid is added, the mas required then would be approx?

Back 22

100

Front 23

Transmission of photons is responsible for?

Back 23

Light areas on the film.

Front 24

All of the following are true of scatter, except?

Back 24

Increases contrast

Front 25

Higher frequency grids have thinner lead strips. True or false?

Back 25

True

Front 26

The distance between the tube (convergence line) and the grid is called?

Back 26

Grid radius

Front 27

Distortion is a misrepresentation of?

Back 27

Shape and size

Front 28

Size distortion in conventional radiography can be ____ only.

Back 28

Magnification

Front 29

As size distortion decreases, the resolution of recorded detail?

Back 29

Increases

Front 30

The ____ the Sid, the ____ the magnification.

Back 30

Greater, smaller

Front 31

As OID increases and SID remains constant, entrance skin exposure?

Back 31

Increases

Front 32

Which occurs when the tube or the image receptor is not properly aligned?

Back 32

elongation, foreshortening.

Front 33

Which of the following will keep size distortion to a minimum?

Back 33

Increases SID

Front 34

The ratio of SID to SOD represents which of the following?

Back 34

Magnification ratio

Front 35

A misrepresentation of the shape of an object may be caused by which of the following?

Back 35

- an angle part

- an angled X-ray tube

- an angled cassette

Front 36

If the SID is increased the same as the OID, what will the resultant radiograph show?

Back 36

No change in size distortion

Front 37

If the SID is increased the same as the OID, what will the resultant radiograph show?

Back 37

No change in size distortion

Front 38

Which of the following will produce the largest recorded image?

Back 38

40” SID, 5” OID

Front 39

Misrepresentation of the true size or shape of an object is the definition of which of the following?

Back 39

Distortion

Front 40

which of the following occurs when the OID is increased?

Back 40

Image is magnified

Front 41

An object measures 7cm in length, the SID is 56mm and the SOD is 48mm, what is the percentage of magnification?

Back 41

1.2%

Front 42

What is the magnification factor is the SID is 183cm and the OID is increased?

Back 42

1.14%

Front 43

What is the size of the actual object if the magnification factor is 23% and the image is 8cm long?

Back 43

.35cm

Front 44

If the magnification factor is 1.2 and the image measures 12” long, what is the length of the object?

Back 44

10”

Front 45

If OID increases:

Back 45

SOD decreases

Front 46

Elongation is caused by:

Back 46

Improper tue alignment

Front 47

Angulation of the tube in order to avoid superimposition or flatten out curved anatomy is called:

Back 47

Controlled distortion.

Front 48

Recorded detail is:

Back 48

Geometric representation of the part being radiographed.

Front 49

Elongation and for shortening are examples of:

Back 49

Shape distortion

Front 50

Communication is the best way to reduce motion. True or false?

Back 50

True