EX2; Digital Imaging

Question 1

What is the definition of digitization

Answer 1

to represent a particular object in form of numerical digits (zeros and ones)

Question 2

What are the two types of digital imaging

Answer 2

direct

indirect

Question 3

This type of digital imaging involves radiographic images obtained by x-ray exposure of solid-state image detectors

Answer 3

direct

Question 4

In direct digital imaging, there is no intermediate step of what

Answer 4

reading or scanning

Question 5

What are the two types of direct digital imaging

Answer 5

charge-coupled device (CCD)

complementary metal-oxide semiconductor (CMOS)

Question 6

This type of digital imaging involves radiographic images obtained by exposing a digital image detector and scanning or digital photo capture of film radiographs

Answer 6

indirect

Question 7

What are the three types of indirect digital imaging

Answer 7

photostimulable storage phosphor plate (PSP)
scanning a film
taking digital photo of a film

Question 8

This was first introduced in 1987 and the image detector is made of high-grade pure silicone

Answer 8

charge-coupled device

Question 9

The image acquisition of the CCD is a process of what

Answer 9

transferring accumulated light or x-ray photons from one electronic well to another to a read-out device

Question 10

This has an amorphous silicon wafer containing an array of pixels coupled to each other

Answer 10

CCD

Question 11

What are four advantages of CCD

Answer 11

instant availability of images
better quality compared to PSP
durable
consistent image quality

Question 12

What are four disadvantages of CCD

Answer 12

expensive
bulky
wire attachment
smaller active area compared to equivalent size film

Question 13

This has silicone-based semiconductors

Answer 13

CMOS

Question 14

Where else besides digital radiographs is CMOS found

Answer 14

video camera detectors

central processing chips of computers

Question 15

What are five advantages to CMOS

Answer 15

instant availability of image
durable
consistent image quality
less expensive that CCD
slightly more rugged than CCD

Question 16

What are four disadvantages to CMOS

Answer 16

expensive compared to PSP
bulky; wireless is even bulkier
wire attachment
smaller active area compared to equivalent film size

Question 17

What are the two components of storage phosphor plates (PSP)

Answer 17

supporting base

outer coating of radiosensitive phosphor material

Question 18

What is the composition of phosphor

Answer 18

europium-doped barium fluorohalide; similar to intensifying screen phosphors

Question 19

What is the difference between PSP phosphor and intensifying screen phosphor

Answer 19

PSP traps a significant number of electrons in its phosphor, which is later read by a laser beam

Question 20

The phosphor layer absorbed x-ray photons, and causes the energy to do what

Answer 20

move valence electron to conduction band

Question 21

The number of electrons stored in PSP is proportional to what

Answer 21

x-ray photons

LATENT IMAGE

Question 22

What is a spectrum of the red laser beam

Answer 22

633nm

Question 23

The trapped PSP electrons return to the valence band and emit what

Answer 23

300-500nm light (green spectrum)

Question 24

The green spectrum light is transited to what and converted to what

Answer 24

the photomultiplier tube and the light energy is converted to electrical enerfy

Question 25

What is the electrical energy of PSP

Answer 25

ADC; stored and displayed as digital image

Question 26

What are four advantages to PSP

Answer 26

wider latitude; forgiving in choice of kVp and mAs available is standard sizes well tolerated by patients economically priced

Question 27

What are five disadvantages of PSP

Answer 27

``` prone to scratches; short life span read-out should be done ASAP (6-8hours) require processing semi-dark room required require exposure to bright light for erasing previous image before reuse ```

Question 28

What are four digital detector characteristics

Answer 28

contrast resolution spatial resolution detector latitude detector sensitivity

Question 29

This is the ability to distinguish different densities in radiographic images

Answer 29

contrast resolution

Question 30

What bit depth do digital detectors capture data

Answer 30

8, 10, 12 or 16

Question 31

How many different densities/gray levels are there with contrast resolution

Answer 31

256-65,536

Question 32

Convention computer monitors display how many bits and gray levels

Answer 32

8 bit | 242 gray levels

Question 33

The human visual system is capable of distinguishing how many gray levels

Answer 33

60 gray levels

Question 34

In a dental operatory environment, less than how many gray levels are distinguishable

Answer 34

30 gray levels

Question 35

This is the ability to identify two objects placed very close to each other

Answer 35

spatial resolution

Question 36

What is the average line pair/mm in D-speed films

Answer 36

20

Question 37

What is the average line pair/mm in digital images

Answer 37

24

Question 38

What is the average line pair/mm in normal untrained eyes

Answer 38

4-6

Question 39

This is the ability of an image detector to capture a range of x-ray exposures of tissue densities ranging from gingiva to enamel (for example)

Answer 39

detector latitude

Question 40

What is the useful detector latitude range

Answer 40

0.5-2.5

Question 41

This is the ability of the detector to respond to smaller amount of radiation

Answer 41

detector sensitivity

Question 42

True or False | There are no standards for dental digital detectors like there are for film (i.e. speed D, E, F)

Answer 42

True

Question 43

What is the film speed equivalent of PSP

Answer 43

F speed

Question 44

What is the dosage of a CCD and CMOS compared to F-speed film

Answer 44

half the dosage

Question 45

What does the monitor consist of

Answer 45

display device circuity enclosure

Question 46

What three things compose the display device of the monitor

Answer 46

cathode ray (256GU) thin film transistor; ultra high resolution organic light emitting diode; higher contrast and better viewing angle than LCD

Question 47

What is the hard copy

Answer 47

paper or film

Question 48

This is an operation that acts to improve, restore, analyze, or change a digital image

Answer 48

image processing

Question 49

What does image processing improve if used judiciously

Answer 49

diagnostic accuracy

Question 50

True or False | Image processing may improve the diagnosis of one disease while obscuring another

Answer 50

True

Question 51

Image processing can be linked to what

Answer 51

fraud

Question 52

This is designed to extract diagnostically important information from an image

Answer 52

image analysis

Question 53

This consists of digital rulers, densitometers, trabecular bone pattern

Answer 53

measurement

Question 54

This consists of automation of detection, classification and quantification of radiological signs

Answer 54

diagnosis

Question 55

What are six advantages of digital imaging

Answer 55

``` instantaneous lower radiation dose consistent quality high signal/noise ratio image manipulation digital subtraction radiography ```

Question 56

What are five disadvantages of digital imaging

Answer 56

``` relatively lower resolution than film quality depends on monitor and printer print quality is often no optimal higher initial cost unwanted manipulation of images ```

Question 57

This is recognized standard for communication of images and related information, its voluntary international in scope

Answer 57

digital imaging and communication in medicine; DICOM

Question 58

What makes DICOM efficient

Answer 58

integration of different modalities in one dental office

Question 59

What makes DICOM portable

Answer 59

simplify exchange of images between dental and medical offices when patients move or require specialist care

Question 60

What gives DICOM integrity

Answer 60

attributes uniquely identify the patient, procedure, procedure date, and protect image integrity