Quality Assurance

Question 1

What is image detail?

Answer 1

the degree of sharpness

Question 2

What is FFD?

Answer 2

Focal-film distance

Question 3

What happens if the tube head is too close to the structure being radiographs?

Answer 3

Theres magnification and loss of distinction of the margins of the structure

Question 4

What should the FFD be set to?

Answer 4

36-48 inches

Question 5

The _____ the focal spot, the _____ detail present on the film

Answer 5

greater; less

Question 6

How do you minimize focal spot?

Answer 6

Place the structure as close to the film as possible

Question 7

What does the density of the image refer to?

Answer 7

degree of blackness of the image

Question 8

______ tissue absorbs _____ radiation than ______ tissue

Answer 8

Thicker; more; thinner

Question 9

What is the major factor that affects density?

Answer 9

mAs

Question 10

What does the mAs setting determine?

Answer 10

The quantity of x-rays produced

Question 11

The higher the mAs, the greater the ______/_____ of the film

Answer 11

darkness/density

Question 12

Besides mAs, what else can affect film density?

Answer 12

peak kilovoltage (kVp)

Question 13

What happens if you increase kVp?

Answer 13

increase in energy level of x-rays produced
results in darker/denser image

Question 14

If you move the tube head closer to the structure being radiographed, what happens?

Answer 14

the image is denser/darker

Question 15

What is the inverse square law?

Answer 15

the intensity of the x-ray beam at a given location is inversely proportional to the square of the distance from the x-ray source

FFD doubled –> intensity is 1/4 original strength

Question 16

What is contrast?

Answer 16

Its the opacity/density difference between two areas or structures on the radiograph

Question 17

What are the two types of contrast?

Answer 17

high contrast/low contrast

Question 18

What are high contrast images?

Answer 18

These images are primarily black/white

Question 19

What is low contrast?

Answer 19

These images have multiple shades of gray w/in the image

Question 20

What is high contrast used for?

Answer 20

Bone structures

Question 21

What is low contrast used for?

Answer 21

Soft tissue, thoracic, abdominal images

Question 22

What has the greatest effect on contrast?

Answer 22

kVp

Question 23

The _________ the kVp, the ________ the scale of contrast

Answer 23

higher; lower

Question 24

What happens w/ kVp in terms of contrast?

Answer 24

with a higher kVp, the x-rays are more uniformly absorbed amongst body tissues, resulting in lower contrast

inversely proportional

Question 25

_____ kVp is preferred for thoracic images and _______ kVp is selected for skeletal images

Answer 25

higher; lower

Question 26

What should you do if the anatomical structures are not visible due to being too dark/over-penetrated?

Answer 26

Decrease kVp by 10-15%

Question 27

What should you do if the anatomical structures are too light/under penetrates with no anatomical structures visible?

Answer 27

Increase kVp by 10-15%

Question 28

What should you do if the anatomical structures are visible but the image is too dark?

Answer 28

Decrease in mAs of 30-50%

Question 29

What should you do if the anatomical structures are visible by the image is too light (has little density)?

Answer 29

Increase mAs by 30-50%

Question 30

What are the three things that must be evaluated for image quality?

Answer 30

Contrast, density, the anatomical structure is centered on the film w/ proper positioning

Question 31

How do you ensure that the anatomical structure requested is centered on the film w/ proper positioning?

Answer 31

Adequate collimation, appropriate R or L marker, and film is properly identified

Question 32

How is a technique chart established?

Answer 32

Using trial and error

Question 33

What factors should be kept constant when creating a technique chart?

Answer 33

film age, screen speed, cassette type, FFD, and developer & fixer age

Question 34

What is a technique chart?

Answer 34

Its a chart developed to use as a guide for the settings on the specific machine that will obtain the best possible diagnostic image