Chapter 25: Digital Imaging
Iannucci: Dental Radiography, 5th Edition
MULTIPLE CHOICE
1. Digital imaging uses _________________ to produce an image.
a.
an x-ray processor
b.
radiographic film
c.
processing chemistry
d.
an electronic sensor and computerized imaging system
2. With digital imaging, the term ___________ is used to describe the pictures that are produced.
a.
radiograph
b.
x-ray film
c.
image
d.
phosphor
3. Your patient is concerned about the amount of x-ray exposure she has had because she had
x-rays taken quite often at her previous dental office. You explain to her that the images are
necessary and you will be taking digital images which require _________ exposure than the
films she previously had taken. Exposure times are ________ than that required for
conventional radiography.
a.
10% to 20% less
b.
20% to 50% less
c.
50% to 90% less
d.
70% to 100% less
4. Most digital imaging systems use a ______________ as the x-radiation source.
a.
flat-bed scanner
b.
conventional dental x-ray unit
c.
commercial analog intraoral camera
d.
commercial digital intraoral camera
5. In order to be used for digital imaging, the x-ray unit timer must be adapted to allow
exposures in a time frame of _______ of a second.
a.
1/5
b.
1/10
c.
1/15
d.
1/100
6. Digital sensors contain distinct units of programmable gray values that are sensitive to x-rays
called
a.
a field arrangement.
b.
pixels.
c.
phosphors.
d.
a grid.
7. How many shades of gray can the human eye distinguish?
a.
16
b.
32
c.
64
d.
256
8. (1) When you are preparing the sensor to use on your patient, it would be best to cover the
sensor with a finger cot and then put on the barrier sleeve. (2) When you are placing the
digital sensor in your patient’s mouth, you would use a different placement technique than
you would normally use when placing a film.
a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second statement is false.
d.
The first statement is false; the second statement is true.
9. Storage phosphor imaging
a.
is a form of direct digital imaging.
b.
is a wired digital imaging system.
c.
uses a sensor with a fiber optic cable.
d.
uses a reusable imaging plate.
10. The images are cleared from the storage phosphor imaging plates by
a.
being processed in an x-ray processing machine.
b.
a clearing step within the scanner.
c.
being exposed to viewbox light for several minutes.
d.
being placed in a microwave oven for 1 minute.
11. Your patient has asked why you prefer digital imaging to film. Which of the following
reasons would you tell her?
a.
The sensors can be autoclaved and reused.
b.
The image appears almost instantaneously for both of us to view.
c.
The images appear in color instead of black and white.
d.
The initial setup costs were lower than it cost to set up film.
12. (1) A primary advantage to digital imaging is the superior gray-scale resolution that results.
(1) Digital imaging uses up to 32 shades of gray.
a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second statement is false.
d.
The first statement is false; the second statement is true.
13. Conventional dental x-ray film has a resolution of ___________ lp/mm.
a.
6 to 8
b.
8 to 12
c.
12 to 20
d.
20 to 50
14. Sensors that cannot be sterilized
a.
should be disposed of between patients.
b.
are wiped off with a surface disinfectant (iodophor) between patients.
c.
require complete coverage with disposable plastic sleeves for each patient.
d.
are placed in an immersion disinfectant for an appropriate amount of time between
each patient.
15. It is questionable whether digital images can be used as evidence in lawsuits, because
a.
the images are inferior to film.
b.
digitized images cannot be transported across state lines.
c.
the original digital image can be enhanced.
d.
a “hard copy” of the image does not exist.
16. (1) Given that the human eye can resolve 8 to 10 lp/mm, a CCD system is inadequate for
diagnosis of dental disease. (2) The majority of research has shown that the traditional
radiographs perform at least as well as digital images and, at times, even better.
a.
Both statements are true.
b.
Both statements are false.
c.
The first statement is true; the second statement is false.
d.
The first statement is false; the second statement is true.
17. Advantages of the use of digital imaging include which of the following?
a.
Sensors are more comfortable than film.
b.
There is an opportunity for an increase in interactive dialogue between the patient
and the radiographer.
c.
Digital imaging has a higher resolution than film.
d.
A better source of legal documentation than film.
18. With the feature of _______________, the gray-scale of the diagnostic image is reversed so
that radiolucent images appear white and radiopaque images appear black.
a.
pseudo-color alteration
b.
digital subtraction
c.
contrast
d.
image orientation
19. Which of the following would be a reason to switch from film to direct digital imaging?
a.
The digital network makes it more difficult to store images.
b.
The digital image cannot be incorporated into the electronic record.
c.
Images cannot be electronically transmitted to other dental professionals.
d.
Digital images can be printed when needed.
20. A sensor with a fiber optic cable linked to the computer is placed into the mouth of the patient
and exposed to x-radiation. This is an example of
a.
phosphor imaging.
b.
use of the CCD camera.
c.
direct digital imaging.
d.
indirect digital imaging.
21. How does the CMOS detector differ from the CCD detector?
a.
The CMOS detector is silicon-based and differs from the CCD detector in the way
that the pixels are read.
b.
The CMOS detector is currently manufactured by one company and claims 25%
less resolution than the CCD detector.
c.
The CMOS detector is more expensive to produce than the CCD detector.
d.
The CMOS detector is less durable than the CCD detector.