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UBC Theses and Dissertations
Evaluation of digital and geometric unsharpnesses in dental radiographs Radan, Elham
Abstract
Recent advances in digital electronic devices have led to developments in digital radiography. Increased interest in imaging systems other than conventional filmbased radiography has been stimulated by anticipated reduction in patient radiation exposure with increased convenience and image quality. With the new imaging systems developing, it is necessary to evaluate the image quality with comparison to conventional film-based radiography. The aim of this study was to develop a definitive evaluation based on an endodontic file model for comparison of the effects of geometric and digital unsharpnesses in dental radiography. The endodontic file has a well-defined outline and small size, which makes it ideal to test resolution. Files of sizes 6, 8, 10 and 15 were placed in the root canal of an extracted lower incisor at 3 different positions with 2mm increments. Radiographs were taken at magnification factors of 1.0,1.1,1.2 and 1.3. Each radiograph was digitized at resolutions of 75, 150, 300 and 600 dots per inch (dpi). A digital visual analog scale was used for the assessment of image quality. Ten observers viewed the 192 digital images and identified the positions of the end of the files and the end of the root. Measured distances between these points were compared with a gold standard (actual file positions). Analysis of variance and paired T-tests were used to demonstrate significant differences. No significant differences were found between the resolutions of 300 and 600 dpi, nor between the magnifications of 1.0 and 1.1. Significant differences were found between the magnification of 1.3 and the others, and the resolution of 75 dpi and the others, for all the files. The effects of geometric unsharpness within the range studied for all the file sizes were not significant except for the magnification of 1.3, which is of little clinical relevance. Based on this study, with endodontic files in an extracted tooth, there is little need for resolutions higher than 300 dpi in clinical dental radiography and geometric unsharpness has no influence on diagnostic information. This may apply to many other aspects of diagnostic imaging.
Item Metadata
Title |
Evaluation of digital and geometric unsharpnesses in dental radiographs
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1999
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Description |
Recent advances in digital electronic devices have led to developments in digital
radiography. Increased interest in imaging systems other than conventional filmbased
radiography has been stimulated by anticipated reduction in patient radiation
exposure with increased convenience and image quality. With the new imaging
systems developing, it is necessary to evaluate the image quality with comparison to
conventional film-based radiography.
The aim of this study was to develop a definitive evaluation based on an
endodontic file model for comparison of the effects of geometric and digital
unsharpnesses in dental radiography. The endodontic file has a well-defined
outline and small size, which makes it ideal to test resolution. Files of sizes 6, 8, 10
and 15 were placed in the root canal of an extracted lower incisor at 3 different
positions with 2mm increments. Radiographs were taken at magnification factors
of 1.0,1.1,1.2 and 1.3. Each radiograph was digitized at resolutions of 75, 150, 300 and
600 dots per inch (dpi). A digital visual analog scale was used for the assessment of
image quality. Ten observers viewed the 192 digital images and identified the
positions of the end of the files and the end of the root. Measured distances between
these points were compared with a gold standard (actual file positions). Analysis of
variance and paired T-tests were used to demonstrate significant differences.
No significant differences were found between the resolutions of 300 and 600 dpi,
nor between the magnifications of 1.0 and 1.1. Significant differences were found
between the magnification of 1.3 and the others, and the resolution of 75 dpi and the
others, for all the files. The effects of geometric unsharpness within the range
studied for all the file sizes were not significant except for the magnification of 1.3,
which is of little clinical relevance. Based on this study, with endodontic files in an extracted tooth, there is little need
for resolutions higher than 300 dpi in clinical dental radiography and geometric
unsharpness has no influence on diagnostic information. This may apply to many
other aspects of diagnostic imaging.
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Extent |
23644851 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-06-15
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0089020
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1999-05
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.