Digital Imaging Foundations #1

Question 1

Digital imaging receptors require MORE or LESS radiation than film to produce an image?

Answer 1

Less radiation

Question 2

Which Solid state Detector is considered more expensive? CCD or CMOS?

Answer 2

CCD

Question 3

Which Solid State Detector has less digital noise? CCD or CMOS?

Answer 3

CCD

Question 4

T/F: the pixels on a digital radiographical images are organized in a matrix

Answer 4

True

Question 5

What is an example of indirect digital imaging?

Answer 5

Photostimulable Phospor (PSP) Technology

Question 6

What is the active area?

Answer 6

The region of the sensor that is capable of capturing an image

Question 7

What are the larger matrix details?

Answer 7

• Smaller pixel size
• Able to enlarge (magnify) more of the images
• Larger file size

Question 8

What is the definition of bit depth of digital radiographic images?

Answer 8

Maximum number of grey shades that an image can present

Question 9

Direct vs indirect digital imaging

Answer 9

Direct: Solid-state sensors
Indirect: Photostimulable phosphor (PSP) technology

Question 10

T/F: Analog has an infinite set of possible values?

Answer 10

True

Question 11

What is pixel matrix?

Answer 11

A matrix that has a set of rows and columns.

Question 12

How can you differentiate composites/amalgam from enamel on a radiograph?

Answer 12

Composite or amalgam is denser then enamel, so it should look more opaque than enamel.

Question 13

Air looks (radiolucent/radiopaque) on a radiograph.

Answer 13

radiolucent

Question 14

The maxillary sinus is filled with ______ and is _______ in the radiograph.

Answer 14

air, radiolucent

Question 15

What sensor does ULSD use?

Answer 15

RVG 6200 (Carestream) sensors

Question 16

What are the disadvantages to using digital radiography?

Answer 16

initial cost is higher and the technology is always evolving - can be obsolete soon

Question 17

Which natural part of the tooth will have the most interaction with photoelectric effect?

Answer 17

Enamel

Question 18

T/F: analog data must have a defined set of possible values

Answer 18

False
this is the case for Digital imaging, however

Question 19

In an 8-bit image, which value is given to pure black?
a. 255
b. 250
c. 0
d. 50

Answer 19

c. 0

Question 20

The larger the pixel matrix, the __________ the pixel size

Answer 20

smaller

Question 21

What does contrast resolution allow you to differentiate between?

Answer 21

different densities

Question 22

Were x-rays discovered with film or digital images?

Answer 22

film

Question 23

Both CCD and CMOS image sensors convert x-ray photons to _________ that gets read by the sensor.

Answer 23

light

Question 24

Solid-state sensors are used for direct or indirect digital imaging?

Answer 24

Direct digital imaging

Question 25

True or False:
One disadvantage of digital radiography is that it requires a higher radiation dose.

Answer 25

False. Advantages of digital radiography include lower radiation doses and elimination of chemical processing.

Question 26

What is sampling in analog-digital conversion?

Answer 26

Grouping a range of analog values together

Question 27

Which of the following best differentiates digital from analog imaging?

expressed in discrete units
infinite set of possible values
contains a lead foil backing

Answer 27

expressed in discrete units (pixels)

Question 28

How does increased sampling impact analog signal?

Answer 28

better representation of signal / higher bit depth

Question 29

For film imaging, where are silver crystals found?

Answer 29

In the emulsion

Question 30

What is the difference between sampling and quantization in regards to analog-digital conversion?

Answer 30

Sampling is grouping a range of values together
Quantization is assigning a single value to each sample

Question 31

What is the one of the differences in film and digital imaging?

Answer 31

Film imaging uses silver crystals while digital imaging uses pixels