Chapter 3 - 2

Question 2

35. The quality of a radiographic image depends on:

a. brightness—visibility of anatomic structures
b. accuracy of the recorded anatomic structural lines
c. contrast—visibility of anatomic structures
d. A and B
e. A, B, and C

Answer 2

Solution: e. A, B, and C

The quality of radiographic image depends on both the visibility of anatomic structures (brightness and contrast) and the accuracy of recorded anatomic structural lines (sharpness).
REF: p.58

Question 3

36. The smallest object that can be detected in an image is the:

a. temporal resolution
b. spatial resolution
c. contrast resolution
d. none of the above

Answer 3

Solution: b. spatial resolution

Spatial resolution refers to the smallest object that can be detected on an image.
REF: p.57

Question 4

37. The accuracy of the anatomic structural lines recorded in the radiographic image is determined by the:

a. temporal resolution
b. spatial resolution
c. contrast resolution
d. none of the above

Answer 4

Solution: b. spatial resolution

The accuracy of the anatomic structural lines recorded in the radiographic image is determined by its spatial resolution.
REF: p.57

Question 5

38. An increase in the amount of unsharpness recorded on the image has what effect on the visibility of anatomic structures?

a. Increased contrast of anatomic structures
b. Decreased contrast of anatomic structures
c. Increased overall visibility
d. Decreased overall visibility
e. A and C
f. B and D

Answer 5

Solution: f. B and D

An increase in the amount of unsharpness recorded on the image decreases the contrast of small anatomic structures, reducing the overall visibility of the structural lines.
REF: p.58

Question 6

39. Radiographic misrepresentation of the size or shape of the anatomic structure being imaged is:

a. magnification
b. elongation
c. foreshortening
d. all of the above

Answer 6

Solution: d. all of the above

Size or shape distortion includes magnification, elongation, and foreshortening.
REF: p.59

Question 7

40. Shape distortion includes:

a. magnification
b. elongation
c. size distortion
d. all of the above

Answer 7

Solution: b. elongation

Shape distortion includes elongation and foreshortening.
REF: p.59

Question 8

41. Size distortion is affected by:
42. SID
43. OID
44. tube angulation

a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3

Answer 8

Solution: a. 1 and 2 only

Size distortion, or magnification, is affected by both SID and OID. Tube angulation affects shape distortion.
REF: p.59

Question 9

42. As seen on the radiographic image, scatter radiation:

a. decreases the visibility of anatomic structures
b. increases the visibility of anatomic structures
c. has no effect on the visibility of anatomic structures
d. increases image contrast

Answer 9

Solution: a. decreases the visibility of anatomic structures

Scatter radiation results in fog, decreasing the visibility of anatomic structures.
REF: p.60

Question 10

43. An increase in noise on the radiographic image:

a. indicates greater quantum mottle
b. is more likely with digital imaging than with film-screen
c. is the result of fewer than appropriate x-ray photons reaching the IR
d. all of the above

Answer 10

Solution: d. all of the above

An increase in the brightness/density fluctuations on the radiographic image means there is more quantum mottle (film) or quantum noise (digital). This is the result of too few photons exposing the IR and is more likely with digital imaging.
REF: p.61

Question 11

44. A fewer amount of photons reaching the IR has what effect on the formation of the image?

a. The visibility of quantum noise is increased on the digital image
b. The visibility of quantum noise is decreased on the digital image
c. The visibility of quantum mottle is increased on the digital image
d. The visibility of quantum mottle is decreased on the digital image

Answer 11

Solution: a. The visibility of quantum noise is increased on the digital image

The fewer the photons reaching the image receptor to form the image, the greater the visibility of quantum noise on the digital image.
REF: p.61

Question 12

45. An unwanted image on a radiograph is:

a. excessive image contrast
b. the result of overexposure
c. an artifact
d. none of the above

Answer 12

Solution: c. an artifact

An artifact is an unwanted image seen on a radiograph.
REF: p.62

Question 13

46. Which of the following artifacts are common to both film-screen and digital imaging?
47. Jewelry covering part of the anatomy being imaged
48. Fog due to scatter
49. Quantum noise/mottle

a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3

Answer 13

Solution: d. 1, 2, and 3

Jewelry in the area of interest, fog, and quantum noise/mottle are artifacts that can be seen on both film and digital images.
REF: p.62

Question 14

47. As compared to digital imaging, film-screen imaging has:

a. a wider dynamic range
b. a narrower dynamic range
c. the same dynamic range
d. no dynamic range

Answer 14

Solution: b. a narrower dynamic range

One of the drawbacks of film-screen imaging is that it has a more narrow dynamic range than digital imaging.
REF: p.63

Question 15

48. Spatial resolution is improved with:

a. increased pixel size
b. increased pixel pitch
c. increased pixel density
d. increased pixel bit depth

Answer 15

Solution: c. increased pixel density

Spatial resolution is improved with an increased number of pixels per unit area, or pixel density. Larger pixel size and pitch reduce spatial resolution, but bit depth doesn’t have any effect.
REF: p.57

Question 16

49. With radiographic imaging, anatomic tissues, such as bone, that absorb most of the radiation result in that area of the image being:

a. more blurred
b. sharper
c. darker (more density)
d. lighter (less density)

Answer 16

Solution: d. lighter (less density)

Bone, absorbing most of the primary radiation, results in fewer photons reaching the IR and a lighter area on the image.
REF: p.47

Question 17

50. Due to ______________________, repeats are often needed with film-screen imaging, because the image is too dark or light.

a. chemical processing
b. the use of intensifying screens
c. its narrow dynamic range
d. its wide dynamic range

Answer 17

Solution: c. its narrow dynamic range

Due to its narrow dynamic range, repeats are often needed with film-screen imaging, because the image is too dark or light.

Question 18

1 T/F During attenuation of the x-ray beam, the photoelectric effect is responsible for the total absorption of the incoming x-ray photon.

Answer 18

True

During attenuation of the x-ray beam, the photoelectric effect is responsible for the total absorption of the incoming x-ray photon.
REF: p.43

Question 19

2 T/F The photoelectric effect is dependent on both the energy of the x-ray photon and the composition of the anatomic tissue.

Answer 19

True

The energy of the x-ray photon must be at least equal to the binding energy of the inner shell electron of the atom of anatomic tissue being imaged.
REF: p.44

Question 20

3 T/F The Compton interaction can occur within all diagnostic x-ray energies.

Answer 20

True

While Compton interactions can occur in all diagnostic x-ray energies, the percentage of Compton interactions increases at higher kilovoltages.
REF: p.45

Question 21

4 T/F Compton interactions are more likely to occur in soft tissue as compared to bone.

Answer 21

False

The probability of a Compton interaction occurring depends on the energy of the incoming photon. Compton interactions are not dependent on the composition of the anatomic tissue.
REF: p.45

Question 22

5 T/F Approximately 20% of the primary x-ray beam actually reaches the image receptor.

Answer 22

False

Less than 5% of the primary x-ray beam actually reaches the image receptor.
REF: p.51

Question 23

6 T/F X-ray absorption is more likely in tissues with a lower atomic number.

Answer 23

False

X-ray absorption is more likely in tissues with a higher atomic number.
REF: p.46

Question 24

7 T/F Beam attenuation is increased with a higher-energy x-ray beam.

Answer 24

False

Beam attenuation is decreased with a higher-energy x-ray beam.
REF: p.47

Question 25

8 T/F An area of increased brightness on a display monitor will show decreased density on a film image.

Answer 25

True Increased brightness and decreased density (overall blackness) are the same. REF: p.50

Question 26

9 T/F The primary factor that affects film-screen density is the quantity of radiation reaching the IR.

Answer 26

True The amount, or quantity, of the radiation reaching the IR is the primary determinant of film-screen density. REF: p.53

Question 27

10 T/F The abdomen has low subject contrast.

Answer 27

True The abdomen, containing organs with very similar tissue characteristics, has low subject contrast. REF: p.54

Question 28

11 T/F The highest quality radiographic image has no unsharpness.

Answer 28

False It is impossible to create an image without any unsharpness. The highest quality radiographic image will have minimal unsharpness. REF: p.57

Question 29

12 T/F Recorded detail is the term commonly used in digital imaging to describe the accuracy of the structural lines that make up the image.

Answer 29

False Spatial resolution is the term commonly used in digital imaging to describe the accuracy of the structural lines that make up the image. Recorded detail is used to identify that quality for film-screen imaging. REF: p.57

Question 30

13 T/F Magnification always results in reduced recorded detail.

Answer 30

True Magnification, or size distortion, always results in reduced recorded detail. REF: p.58

Question 31

14 T/F Radiographic images of structures are always magnified when compared to the actual structure.

Answer 31

True In that there is always some OID of the structure, the image is always larger than the actual structure. REF: p.59

Question 32

15 T/F When an image is distorted, spatial resolution is increased.

Answer 32

False When an image is distorted, spatial resolution is also reduced. REF: p.59

Question 33

16 T/F Shape distortion can be useful in radiographic imaging.

Answer 33

True While it is generally not a positive quality, there are times that shape distortion is used in radiographic imaging to allow structures to be seen. REF: p.60

Question 34

17 T/F Quantum noise is significantly more likely with digital imaging.

Answer 34

True As compared to film-screen imaging, digital images are much more likely to demonstrate quantum noise, due to the computer’s ability to take a very low exposure and adjust the brightness to an appropriate level. REF: p.63

Question 35

18 T/F The brightness/density and contrast of film-screen and digital manifest images can be adjusted, just in different ways.

Answer 35

False The density and contrast of film-screen images cannot be adjusted following exposure. REF: p.64