Chapter 08: Dental X-Ray Image Characteristics
Iannucci: Dental Radiography, 5th Edition
MULTIPLE CHOICE
1. Which of the following areas would appear the most radiopaque on a dental image?
a.
Composite
b.
Amalgam
c.
Air space
d.
Enamel
2. Density is defined as
a.
a radiopaque image.
b.
a radiolucent image.
c.
the overall blackness or darkness of an image.
d.
the difference in degrees of blackness between adjacent areas on a dental image.
3. You are showing your patient a bite-wing image. Your patient points to a portion of the tooth
that is the most radiopaque and wants to know what it is. What portion of the tooth is your
patient pointing to?
a.
The enamel
b.
The pulp
c.
The denton
d.
The periodontal ligament space
4. Radiolucent refers to that portion of a dental image that is
a.
black.
b.
white.
c.
contains the tooth.
d.
within the plastic base.
5. If the milliamperage is increased, the receptor density ________, and the image appears
_________.
a.
increases; lighter
b.
increases; darker
c.
decreases; darker
d.
decreases; lighter
6. If the operating kilovoltage is increased, the receptor density ____ because the average energy
of the x-rays is raised.
a.
increases
b.
decreases
c.
remains the same
d.
is divided by two
7. You have to take retake a dental image on your patient because the image is too light and is
undiagnostic. Which of the following could you change to produce an image with increased
density?
a.
Increasing the exposure time
b.
Increasing the subject thickness
c.
Decreasing the milliamperage
d.
Decreasing the operating kilovoltage
8. The teeth on your patient’s images appear very radiopaque and the periodontium and tissue
appear very radiolucent. Your patient’s dental image has
a.
high density.
b.
low density.
c.
low contrast.
d.
high contrast.
9. A dental image that has ______________ is said to have high contrast.
a.
a very dark overall appearance
b.
a very light overall appearance
c.
many shades of gray
d.
very dark areas and very light areas
10. An increase in ___________ temperature will result in a film with increased contrast.
a.
development
b.
water bath
c.
fixer
d.
room
11. When a high operating kilovoltage is used, (low/high) subject contrast and (many shades of
gray/areas of black and white) are seen on the dental image.
a.
Low subject contrast; many shades of gray
b.
Low subject contrast; areas of black and white
c.
High subject contrast; many shades of gray
d.
High subject contrast; areas of black and white
12. The range of useful densities seen on a dental image is termed the
a.
film contrast.
b.
subject contrast.
c.
scale of contrast.
d.
kilovoltage peak.
13. A stepwedge will reveal that images taken at a lower kV will have __________ than images
taken at a higher kV.
a.
more shades of gray
b.
higher contrast
c.
lower contrast
d.
both A and C
14. The typical stepwedge is constructed of
a.
aluminum.
b.
steel.
c.
wood.
d.
copper.
15. A stepwedge will reveal that images taken at a higher kV will have _____________ versus
images taken at a lower kV.
a.
long-scale contrast
b.
high contrast
c.
only two densities
d.
many areas of black and white
16. The geometric characteristic of _____________ refers to an image that appears larger than the
actual size of the object it represents.
a.
magnification
b.
distortion
c.
sharpness
d.
parallax
17. Which of the following influencing factors would degrade sharpness?
(1) Smaller silver halide crystal size
(2) Larger silver halide crystal size
(3) Smaller focal spot
(4) Larger focal spot
a.
1 and 3
b.
1 and 4
c.
2 and 3
d.
2 and 4
18. The primary factor that limits the size of the tungsten target is
a.
the cost of the materials.
b.
heat production.
c.
the limited kinetic energy of the electrons.
d.
the limited kinetic energy of the photons.
19. Which of the following factors would improve image sharpness?
a.
Larger focal spot
b.
Larger crystal size in the film
c.
Smaller crystal size in the film
d.
Patient movement during x-ray exposure
20. In order to use the paralleling technique when taking periapical images on your patient, you
will need to place the receptor approximately an inch from the teeth. Which of the following
will you need to do to decrease image magnification?
a.
Increase target-receptor distance.
b.
Decrease target-receptor distance.
c.
Decrease source to object distance.
d.
There is no change in magnification; therefore, no changes need to be made.
21. A longer position-indicating device (PID) results in
a.
an increased target-receptor distance.
b.
a more divergent x-ray beam.
c.
more image magnification than when a shorter PID is used.
d.
an increased object-receptor distance.
22. To minimize dimensional distortion, the object and receptor must be _____________ one
another.
a.
perpendicular to
b.
parallel to
c.
at a 45-degree angle to
d.
more than the length of the PID apart from
23. You are taking dental images on your patient. You have directed the position indicating
device (PID) perpendicular to the tooth and the receptor. Which of the following would you
minimize by doing this?
a.
Sharpness
b.
Grain size
c.
Focal spot size
d.
Dimensional distortion