Exam 1 - 7. Digital Imaging

Question 1

2

Digital imaging has ____ less radiation dose than film imaging.

Question 2

6

1 Bit = ____

Question 3

6

1 byte = ____ bits

Question 4

6

What is the normal display for binary system?

Question 5

6

What is the twelve bit sensory?

Question 6

7

What is the smallest element of a digital picture?

Question 7

7

Digital images are numeric. There are _____ of pixels and different shades of ____ in each pixel.

Question 8

8

Pixels are arranged in rows and columns to form the _____.

Question 9

9

Pixel values typically represent ____

Question 10

9

Digitization implies that a digital image is an ____ of a real scene.

Question 11

13

What are three things needed for image acquisition?

Question 12

14

What is the direct digital image receptor?

Question 13

14

What is the indirect digital image receptor?

Question 14

16

Sensor is a laminate of _____ screen, ____ faceplate, and _____ layer.

Question 15

16

Fiber optic faceplate protects _____ layer and provides _____.

Question 16

17

The semiconductor layer is usually made up of _____.

Question 17

17

With the semiconductor layer, electrons are attracted toward the most _____ potential in the device where they create _____.

Question 18

17

Each charge packet corresponds to ______.

Question 19

17

With the semiconductor layer, the amount of electron hole pairs is proportional to the amount of ____ an area receives.

Question 20

18

Each pixel is like a tiny battery with its charge equal to the ______ trapped inside. The computer records the charge in each pixel and converts it to a _____.

Question 21

20

Every digital image is “born” _____ to _____.

Question 22

20

What is the term for “a small range of voltage values are grouped together as a single value?

Question 23

20

What is the term for “Every sampled signal is assigned a numerical value”?

Question 24

22

Charge-coupled device read in _____ fashion.

Question 25

22

For complementary metal oxide semiconductors, each pixel is _____.

Question 26

23

The emission by a substance of stored energy as light is referred to as _____.

Question 27

23

Photostimulable phosphor playes (indirect digital imaging) consist of reusable imaging plates coated with ____ instead of the sensor

Question 28

23

What is the main advantage of photostimulable phosphor plates?

Question 29

24

The PSP plate is made of _______.

Question 30

27

What is a pro of CCD/CMOS compared to PSP?

Question 31

27

What are three pros to PSP compared to CCD/CMOS.

Question 32

30

As exposure to x-ray photons increases, the degree of darkening _____, and so the density _____.

Question 33

30

What are three factors affecting the radiographic density of an image?

Question 34

31

What is the most important factor affecting radiographic density of an image?

Question 35

31

Increasing the milliamperage (mA), peak kilovoltage (kVp), or exposure time increases the _____ reaching the film and
thus increases the ______.

Question 36

31

For subject thickness, the thicker the subject, the more the beam is attenuated, and the ____ the resultant image.

Question 37

31

The greater the density of a structure within the subject, the ____ the attenuation of the x-ray beam directed through the subject or area.

Question 38

32

Dense objects (which are strong absorbers) cause the radiographic image to be light and are said to be _____.

Question 39

32

Objects with low densities are weak absorbers. They allow most photons to pass through, and they cast a dark area o film that corresponds to the ______ object.

Question 40

33

What is the term for the difference in density between areas on the radiograph?

Question 41

33

Radiographic contrast depends on what three things?

Question 42

34

What four things does subject contrast depend on?

Question 43

34

What is the formula for subject contrast?

Question 44

34

What is the relationship between kVp and subject contrast?

Question 45

36

Resolution is not that important for detecting _____. ___ and ____- plays a much larger role.

Question 46

39

What are three useful tools in digital image processing? What are two things that are sometimes useful?

Question 47

40

What is the best means to alter the brightness or contrast of an image?