Final Review

Question 1

Degradation of an image in CR can occur if:

Answer 1

• exposed IP is not processed soon after exposure

- exposed IP has been exposed to high enough temperatures

Question 2

Which portion of the IP records the CR image?

Answer 2

Photostimulable phosphor

Question 3

Factors that influence the emission spectrum are:

Answer 3

mAs, kVp, Z, voltage ripple, added filtration

Question 4

Two exposures are taken. Exposure 1 is taken with an 8:1 grid, and exposure 2 with no grid. How would the patient dose and radiographic density be affected for exposure 2?

Answer 4

No effect on patient dose, increased radiographic density

Question 5

The most common cause of tube failure is?

Answer 5

Vaporization

Question 6

In an x-ray exposure, the majority of the x-rays in the primary beam are?

Answer 6

Bremsstrahlung

Question 7

A patient presents with a pathology that reduces the mass density of their tissue, resulting in decreased beam attenuation. What can this pathology be classified as, and how should technique be adjusted?

Answer 7

Destructive, decrease technique

Question 8

A chest x-ray was taken using AEC and the center cell was selected. Predict the appearance of the image

Answer 8

-spine would have optimum density

Question 9

If a grid was placed with the grid lines transversely on the table and the tube was angled 15 degrees cephalad, what grid error would occur?

Answer 9

Off level

Question 10

Which factors when decreased will increase radiographic density?

Answer 10

• grid ratio

- part thickness

Question 11

If an image is determined as “too light” the mAs should be increased by

Answer 11

Double it (x2)

Question 12

What is an example of a situation where you would utilize a technique chart instead of using AEC?

Answer 12

• pregnant
• finger x-ray
• post op hip patient

Question 13

Radiographic contrast is influenced by?

Answer 13

• differential tissue absorption

- matrix characteristics

Question 14

In which part of the circuit is the step down transformer located?

Answer 14

Filament side

Question 15

When comparing film/screen to digital imaging an advantage of digital imaging is?

Answer 15

Improved contrast resolution

Question 16

Quantum mottle can be decreased by?

Answer 16

-decrease kV, use higher mA

Question 17

Which of the following is the geometric characteristic of a computerized image?

Answer 17

Spatial resolution

Question 18

Heat units formula:

Answer 18

HU=kVp x mA x time x modification factor

Question 19

Total filtration in beam

Answer 19

Equals added and inherent filtration

Question 20

Histogram

Answer 20

Graphical representation of all the densities on the image, raw data of image

Question 21

what is an acceptable repeat rate?

Answer 21

5%

Question 22

An artifact caused by backscatter would look like?

Answer 22

Dark lines

Question 23

What happens to the mAs when the exposure time is halved?

Answer 23

It is halved

Question 24

After substantially increasing collimation, what should be done to the technical factors to maintain density?

Answer 24

-mAs should be increased

Question 25

When changing the visibility of an image by using the LUT what is being altered?

Answer 25

Pixel value

Question 26

Recorded detail is defined as?

Answer 26

The accuracy of structural lines recorded

Question 27

Shape distortion will result from?

Answer 27

Angling the central ray

Question 28

______ is the ability of an imaging system to distinguish between adjacent structures

Answer 28

Resolution

Question 29

The relationship between focal spot size and distance is?

Answer 29

Geometric unsharpness

Question 30

An exposure is taken with a stationary high ratio grid. The resultant image shows extreme loss of density on the side of the image. What grid error has occurred?

Answer 30

Off center

Question 31

What has the most detrimental effect on recorded detail?

Answer 31

Motion

Question 32

As collimation increases (making light smaller), ____ increases

Answer 32

Contrast

Question 33

An image that requires little or no post processing can be described as?

Answer 33

Diagnostic

Question 34

An image described as having many shades of grey is _____ contrast

Answer 34

Low contrast

Question 35

The equivalent effect on density of doubling the mAs is?

Answer 35

Increasing the kVp 15%