Chapter 8: Digital Imaging (includes image mounting and viewing terms from Chapter 11)

Question 1

Define the term: analog image

Answer 1

an image produced on conventional film that looks like the thing it represents

Question 2

Define the term: anatomic order

Answer 2

the order in which teeth are arranged within the dental arches

Question 3

Define the term: beam alignment device

Answer 3

• a device used to align the position-indicating device in relation to tooth and image receptor
• positions the intraoral image receptor in the mouth and retains the image receptor in position during exposure
• helps stabilize the image receptor in the mouth and reduces the chances of movement, thus reducing the patient’s exposure to x-radiation

Question 4

Define the term: bit-depth image

Answer 4

the number of possible gray-scale combinations for each pixel

Question 5

Define the term: charge-coupled device (CCD)

Answer 5

a solid-state silicon chip detector found in an intraoral digital sensor that converts light or x-ray photons into an electrical charge or signal

Question 6

Define the term: complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)

Answer 6

• silicon-based detector used in digital imaging
• differs from the charge-coupled device in the way that pixels are read

Question 7

Define the term: curve of Spee

Answer 7

the anterior-posterior anatomic curvature of the occlusal surfaces of the teeth

Question 8

Define the term: digital image

Answer 8

an image composed of pixels

Question 9

Define the term: digital imaging

Answer 9

a system of filmless imaging used to capture an image using a sensor, breaking it into electronic pieces, and presenting and storing the image using a computer

Question 10

Define the term: digital subtraction

Answer 10

a feature of digital imaging used to reverse the gray scale as an image is being viewed, causing radiolucent images (normally black) to appear white and radiopaque images (normally white) to appear black

Question 11

Define the term: digitize

Answer 11

in digital imaging, to convert an image into digital form that, in turn, can be processed by a computer

Question 12

Define the term: direct digital imaging

Answer 12

a method of obtaining a digital image in which an intraoral sensor is exposed to x-radiation to capture an image that can be viewed on a computer monitor

Question 13

Define the term: image

Answer 13

a picture or likeness of an object

Question 14

Define the term: image receptor

Answer 14

a recording medium (ex: PSP plate, digital sensor)

Question 15

Define the term: indirect digital imaging

Answer 15

a method of obtaining a digital imaging from a sensor after exposure to x-rays by using a scanner to convert information into a digital form so that it can be viewed on a computer monitor

Question 16

Define the term: interpret

Answer 16

to offer an explanation

Question 17

Define the term: image interpretation

Answer 17

• an explanation of what is viewed on a dental image
• the ability to read what is revealed by a dental image

Question 18

Define the term: labial mounting

Answer 18

an image mounting method in which the radiographs are placed in the mount for the dental radiographer to view the images from the labial aspect

Question 19

Define the term: line pairs/millimeter (lp/mm)

Answer 19

a measurement used to evaluate the ability of the computer to capture the resolution (detail) of an image

Question 20

Define the term: mount

Answer 20

to place in an appropriate setting for display or study

Question 21

Define the term: pixel / picture element

Answer 21

in digital electronic images, digital information is contained in, and presented as, discrete units of information

Question 22

Define the term: sensor

Answer 22

in digital imaging, an image receptor that is used to capture an intraoral or extraoral image

Question 23

Define the term: storage phosphor imaging

Answer 23

an indirect method of obtaining a digital image in which the image is recorded on phosphor-coated plates and then placed into an electronic processor, where a laser scans the plate and produces an image on a computer screen

Question 24

Define the term: lingual mounting

Answer 24

an image mounting method in which the radiographs are placed in the mount for the dental radiographer to view the images from the lingual aspect

Question 25

Define the term: analog-to-digital converter (ADC)

Answer 25

the method used to convert data elements acquired by the sensor are communicated to the computer in analog form and then converted into digital form

Question 26

True or false: Digital imaging requires less radiation than conventional film.

Answer 26

True

Question 27

Why does digital imaging require less radiation than conventional film?

Answer 27

the digital sensor is more sensitive to x-radiation than conventional film

Question 28

What is the difference in the percentage of exposure time for digital imaging compared to conventional film?

Answer 28

50-90% less exposure time

Question 29

What are the two most common types of direct digital imaging receptors?

Answer 29

• charge-coupled device (CCD)
• complementary metal oxide semiconductor-active pixel sensor (CMOS-APS)

Question 30

What are the two methods of obtaining a digital image?

Answer 30

• direct digital imaging
• indirect digital imaging

Question 31

What type of image receptor is common when using indirect digital imaging?

Answer 31

photo-stimulable phosphor imaging (PSP) plate

Question 32

True or false: The PSP plate used in indirect digital imaging is a one-time-use product.

Answer 32

False

Question 33

What can be used to help stabilize the image receptor during exposure?

Answer 33

beam alignment device

Question 34

When comparing digital imaging to conventional film, what is the advantage of the gray-scale resolution?

Answer 34

digital imaging has a greater gray-scale resolution with up to 256 shades of gray, in comparison to 25 shades of gray on conventional film

Question 35

When comparing digital imaging to conventional film, what is the advantage of the radiation dose?

Answer 35

digital imaging requires less radiation than conventional film, thus reducing the patient’s exposure

Question 36

When comparing direct digital imaging to conventional film, what is the advantage of speed?

Answer 36

direct digital imaging produces the image instantly and does not require any processing time

Question 37

When comparing digital imaging to conventional film, what is the advantage of the quality of diagnostic images?

Answer 37

the dimensional and geometric factors of digital imaging are greater

Question 38

What is one of the main disadvantages of digital imaging in comparison to conventional film?

Answer 38

the size and thickness of the sensor can be uncomfortable for patients or can be more common in inducing their gag reflex