Ideal radiograph

OMR, CODS, DVG
www.indiandentalacademy.com

An ‘Ideal Radiograph’ is the one with optimum
density, maximum detail and sufficient contrast
to make the detail apparent. The image should
be sharp, centered and have the same size
and shape as that of the object.
OMR, CODS, DVG
DEFINITION
Image Attributes (Qualities / Properties)
(Other attributes : Film latitude, Radiographic mottle, Image clarity)
density
density
density
Density,
contrast
contrast
contrast
Contrast,
detail
detail
detail
Detail,
sharp
sharp
sharp
Sharpness,Speed

OMR, CODS, DVG
DENSITY
“Overall degree of darkening of a processed
film”
Dark
Radiograph
Light
RadiographJust Right!
High Density Low DensityOptimum Density
=
0.5 to 2.0

OMR, CODS, DVG
DENSITY
“Overall degree of darkening of a processed
film”
• Exposure factors -
kVp, mA, S, Filtration, Collimation, TID
• Subject thickness & density
• Processing factors -
developing time, temperature,
concentration
Factors Affecting Density:

OMR, CODS, DVG
CONTRAST
“Difference in densities in different regions of the
film”
Low Contrast
High Contrast
Sufficient Contrast

OMR, CODS, DVG
CONTRAST
“Difference in densities in different regions of the
film”
OPTONICA SUPER SHARP
OPTONICA SUPER SHARP
Low Contrast
High Contrast
Useful for study of
periodontal bone
loss
Useful for study of
periodontal bone
loss
Useful for detection
of dental caries
Useful for detection
of dental caries

OMR, CODS, DVG
CONTRAST
“Difference in densities in different regions of the film”
• Exposure factors - kVp
• Subject contrast
• Film fog due to scattered radiation
• Processing factors - temperature,
concentration
Factors Affecting Contrast:

OMR, CODS, DVG
DETAIL(RESOLUTION)
“Ability of a radiograph to separately record
closely spaced objects”

OMR, CODS, DVG
DETAIL(RESOLUTION)
Silver bromide crystalwww.indiandentalacademy.com

OMR, CODS, DVG
DETAIL(RESOLUTION)
• Size of silver bromide
crystals
• Use of intensifying screens
• Motion
• Film contrast
Factors Affecting Detail:

OMR, CODS, DVG
SHARPNESS (DEFINITION)
“Effectiveness of a radiograph to
precisely define an edge”

OMR, CODS, DVG
SHARPNESS (DEFINITION)
• Size of the focal spot
• Focal spot to object and object to film
distance
• Motion
• Size of the silver bromide crystals
• Use of intensifying screens
Factors Affecting Sharpness:
“Effectiveness of a radiograph to
precisely define an edge”

OMR, CODS, DVG
SPEED
“Amount of radiation required to
produce density of 1”
More the radiation required, slower is the film.
Lesser the radiation required, faster is the film.
Film speed is designated by alphabets A, B, C, D,
E‘A’ is the slowest film.
‘E’ is the fastest film.

OMR, CODS, DVG
SPEED
“Amount of radiation required to
produce density of 1”
Small crystal size --> Slow film Large crystal size --> Fast film

OMR, CODS, DVG
DEFINITION
An ‘Ideal Radiograph’ is the one with optimum
density, maximum detail and sufficient contrast
to make the detail apparent. The image should
be sharp, centered and have the same size
and shape as that of the object.

OMR, CODS, DVG
1. The size of the focal spot should be as small as
possible.
2. The focal spot to object distance should be as
large as possible.
3. The object to image receptordistance should be as
small as possible.
4. The image receptorshould be placed parallel to the
object.
5. The central ray should be perpendicularto object
and image receptorin both vertical and
horizontal planes.
6. The object should be centered on the image
receptor. www.indiandentalacademy.com

OMR, CODS, DVG
1. The size of the focal spot should be as
small as possible.
Pin point
focal spot
1 x 0.8 mm
focal spot
Limiting factor : Heat dissipation

OMR, CODS, DVG
2. The focal spot to object distance should be as large
as possible.
Largerpenumbra
(zone of unsharpness)
&
Image magnification
Smallerpenumbra
&Less
image magnification
Limiting factor : Inverse square lawwww.indiandentalacademy.com

OMR, CODS, DVG
3. The object to image receptordistance should be as
small as possible.
Largerpenumbra
&
Image magnification
Smallerpenumbra
&Less
image magnification
Limiting factor : Oral anatomy

OMR, CODS, DVG
4. The image receptorshould be placed parallel
to the object.
Size and shape distortion if image
receptornot parallel to the object.

OMR, CODS, DVG
4. The image receptorshould be placed parallel
to the object.
Limiting factor : Oral anatomy

OMR, CODS, DVG
5. The central ray should be
perpendicularto object and image receptor
in both vertical and horizontal planes.
Image size < Object sizeImage size > Object sizeImage size = Object size

OMR, CODS, DVG
5. The central ray should be
perpendicularto object and image receptor
in both vertical and horizontal planes.
If the central ray is not perpendicular in
the horizontal plane, overlapping of
shadows of adjacent structures results.
e.g. overlapping of proximal surface
shadows in periapical and bitewing
radiography.
If the central ray is not perpendicular in
the horizontal plane, overlapping of
shadows of adjacent structures results.
e.g. overlapping of proximal surface
shadows in periapical and bitewing
radiography.

OMR, CODS, DVG
6. The object should be centered on
the image receptor.
Complete Image Incomplete Image

OMR, CODS, DVG
Summary of Factors Directly Affecting Image
Attributes
Density Contrast Detail Sharpness
kVp
mA
No Collimation
Focal Spot
Size
Focal Spot-
Object
Distance
Expo. Time

OMR, CODS, DVG
Summary of Factors Directly Affecting Image
Attributes
Density Contrast Detail Sharpness
Object- Film
Distance
Motion
Subject
Density &
Thicknes
s
Developing
Time, Temp. &
Concentration
AgBr Crystal
Size www.indiandentalacademy.com

Ideal radiograph

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Ideal radiograph