13. B (FILM IMAGE) Flashcards
True or false
all films, even after processing, do not look the same
True
radiographic assessment is _____; hence, a common
understanding of it is needed
subjective
(FILM IMAGE)
an ideal radiograph has the ff.:
- represents the area radiographed
- devoid of technical errors
in ______ radiographs, there is found the colors black and white and varying shades of gray
periapical
radiolucent
A. Black
B. White
C. Gray
A
produced due to lack of density of an object,
permeating the passage of x-ray beams without
any attenuation
A. Black
B. White
C. Gray
A
ex.: air spaces or soft tissues such as gingiva
A. Black
B. White
C. Gray
A
radiopaque
A. Black
B. White
C. Gray
B
produced by dense structures that absorb or
resist the passage of x-ray beams
A. Black
B. White
C. Gray
B
ex.: enamel, dentin, bone
A. Black
B. White
C. Gray
B
areas where the x-rays have stopped to a varying degree
A. Black
B. White
C. Gray
C
True or false
radiolucent or radiopaque does not mean totally black or totally white; both have range
T
dark gray to black
Radiolucent
(range)
light gray to white
Radiopaque
(range)
True or false
black, white, or gray images will depend on the thickness/density or material of the structure;
different materials = different radiographic images
T
True or false
when radioactive exposure happens, some x-ray beams pass right through towards the film, while some will not because of dense/hard tissues and their dense structure
T
enamel, dentin, cementum
A. Dense/Hard Tissues
B. Hollow/Soft Tissues
A
gingiva, air spaces, sinus
A. Dense/Hard Tissues
B. Hollow/Soft Tissues
B
FILM IMAGE visual characteristics are?
o density
o contrast
FILM IMAGE geometric characteristics are?
o sharpness
o magnification
o distortion
refers to the overall darkening of the radiograph
DENSITY
usually depends on the degree of silver blackening in the
exposed or processed radiograph
DENSITY
if density is?
too dark or there is poor radiographic quality
A. Too High
B. Too Low
A
if density is?
too light; poor diagnostic quality as well
A. Too High
B. Too Low
B
DENSITY depends on?
o milliamperage
o kilovoltage peak
o exposure time
o density of the subject thickness
o developmental conditions
refers to the darkening of the whole radiograph image itself
DENSITY
difference in contrasting radiodensities and the decrease of blackness in adjacent areas present in a dental radiograph
CONTRAST
refers to the ______ densities between two or more adjacent
areas such as: enamel-dentin-cementum-bone
CONTRAST
essential in the differentiation of structures
CONTRAST
short contrast scale
A. Two Densities
B. Many Densities
A
long contrast scale
A. Two Densities
B. Many Densities
B
can be influenced by the film quality and processing
CONTRAST
object influences the radiographic contrast
SUBJECT CONTRAST
influenced by the thickness, density & composition of the subject
SUBJECT CONTRAST
depends on the kilovoltage peak
RADIOGRAPHIC CONTRAST
decreased contrast
A. Increased kvP
B. Decreased kvP
A
increased contrast
A. Increased kvP
B. Decreased kvP
B
CONTRAST is also influenced by:
o milliamperage
o exposure time
o processing conditions
how well a boundary between 2 contrasting radiodensities is delineated
SHARPNESS
fuzzy unclearness surrounding the radioactive image
PENUMBRA
the sharpness/blurriness of the radiographic image depends on the focal spot:
PENUMBRA
“pen”
almost
“umbra”
shadow
large shadow
A. Large Focal Spot
B. Small Focal Spot
A
less shadow
A. Large Focal Spot
B. Small Focal Spot
B
better, giving a sharper image
A. Large Focal Spot
B. Small Focal Spot
B
______ also depends on the film composition and the size of the silver halide crystals
sharpness
the emulsion of faster film are large silver halide crystals
that produce less image ____
sharpness
smaller silver bromide crystals produce a sharper image
sharpness
another factor is movement which causes loss of image sharpness; could be due to ____[3]
cone, patient or receptor
____ problems could include: loose areas, hinges, or screws
cone
radiographic image that appears larger than the actual size of the object radiographed
MAGNIFICATION
ex.: the tooth length of tooth 11 is 19-25 mm; when the radiograph reaches 30 mm or larger, the cone/film must be repositioned to adjust the ____
MAGNIFICATION
factors that influence magnification:
o source-object distance
o object-film distance
o large effective focal spot
T or f
increasing the target-object distance will decrease magnification
T
ex.: using a 16-inch cone produces an image almost the same length as the actual object, while using an 8-inch cone will produce a larger radiographic image
MAGNIFICATION
T or f
Increasing object-film distance will decrease magnification
F
(DECREASING object-film distance will decrease magnification)
a variation in the size and shape of the object being radiographed
DISTORTION
caused by improper object-film alignment
DISTORTION
film must be parallel to the tooth and perpendicular to the
x-ray beam (depending on the technique)
DISTORTION
this makes the tooth appear larger or fatter (when toward you) or thinner
(away from you)
DISTORTION
x-ray tube with a wrong vertical angulation will elongate or
shorten the tooth
DISTORTION
FACTORS THAT INFLUENCE A RADIOGRAPH’S DIAGNOSTIC QUALITY. [11]
→ milliamperage
→ kilovoltage peak
→ exposure time
→ density of the object
→ speed of the film
→ collimation
→ source-object distance
→ inverse square law
→ ideal technique and film processing conditions
→ good x-ray film quality
→ use of a small effective focal spot
helps as a diagnosis tool
(FILM IMAGE)p
