AND ACCURACY ANALYSIS USING DIFFERENT DIGITAL IMAGING AND

165 Pages·2002·6.96 MB·English

TEIE REPRODUCIBILITY AND ACCURACY OF CEPHALOMETRIC
ANALYSIS USING DIFFERENT DIGITAL IMAGING MODALITIES AND
IMAGE COMPRESSION
SUZANNE CZIRAKI
B.Sc., M.Sc., B.Ed.,D .D.S.
A thesis submitted in confomity with the requirements
for the degree of Master of Science
Graduate Department of Dentistry
University of Toronto
8 Copyright by Suzanne Elizabeth Cziraki 200 1
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THE REPRODUCIBILITY AND ACCURACY OF CEPHALOMETRlC ANALYSIS
USING DIFFERENT DIGITAL IMAGING MODALITIES AND IMAGE
COMPRESSION, Master of Science, 2001, Suzanne E. Cziraki, BSc, MSc, BEd, DDS,
Graduate Department of Dentistry, University of Toronto.
ABSTRACT
This study evaluated and cornpared the reproducibility and accuracy of cephdometric
landmarks and measurernents between conventional radiographie film and the
corresponding indirect, JPEG compressed or direct digital images (DI).
Twentysne conventional films were indirectly digitized using a scanner, and TIFF
images were converted to JPEG files using 2 levels of compression (12:l and 251).
Simultaneous acquisition of conventional and direct DI (stimulable-storage phosphor
(SPP)) was obtained for thirty patients.
Three observers for the indirect and one observer for the direct DI identified 17 and 22
landmarks respectively on the cornputer monitor. X and y-coordinates were recorded and
cephalomeûic measurernents calculated.
Statistical andysis involved use of the paired samples t-tests and ANOVA models.
The results showed that indirect DI have equivalent landmark reproducibility with
conventional film. JPEG compression of indirect DI at 251 level results in loss in
accuracy of cephaiornetric measurement when comparai to non-compressed DI, whereas,
JPEG at 12: 1 did not. Direct DI were less accurate for 8 out of 2 1 landmarks but clinical
accuracy of cephalometric measurement was equivalent to conventional film.
.. .
Ill
ACKNOWLEDGEMENTS
The following individuals have played an integrai part in the completion of this M.Sc. thesis. It is
with heartfelt acknowledgement that 1 thank you all.
This thesis is dedicated to my husband John Duncan, who stood by me and encourageci me as I
pursued yet another academic degree. A special thank you to my beloved children, Madeleine
and Elizabeth who were both bom during the course of this degree and reminded me daily of the
tme meaning of life. 1 wish to thank my parents, Gladys and John Cziraki, who supporteci me in
every way possible in order that 1 rnight attain this goal.
Dr. MJ Pharoah, my thesis supervisor, who was my mentor and fnend over the past three years
providing encouragement and enthusiasm for this project. He is a gified teacher and a talented
academic who provided first-rate support in al1 phases of this research.
Drs. HP Lawrence, CG Petrikowski, P Birek, PE Rossouw, members of my research cornmittee,
for their guidance and advice during the course of this research.
Dr. H Holmes, for his help with the cephalometric software.
Dr. R Walker, for providing the inspiration to pursue research in the area of digital radiology.
Drs. J Posluns and D Raveli and Mrs. G Jorgenson, my observers for the research project, who
gave unselfishly of their time.
Patricia Shuter and the radiology support staff, for their technical assistance in the acquisition of
the digital radiographs.
Mrs. J Hoffmeister, for her help with the Burlington Growth Centre radiographs.
Mrs. Lily Young, for her clerical help.
DenOptidGendex Industries for providing the equipment for the direct digital imaging project.
This research was funded by a Faculty of Dentistry Research Grant.
PREFACE
THESIS FORMAT
This M.Sc. thesis is presented in the 'Publishable Sîyle'. Chapters 2 and 3 will be
submitted for publication and they are presented in their publishable fom except for
minor changes and additions that were incorporated to improve and enhance readability.
A general introduction and Concluding Discussion are included to put the experimental
work in context with the cwrent knowledge.
PUBLICATIONS that wili arise from the thesis chapters include:
PAPER 1 FROM CEIAPTER 2.
Cziraki SE, Pharoah MJ, Lawrence HP, Petrikowski CG, Birek P and Rossouw PE.
impact of lossy Joint Photographic Experts Group (JPEG) compression on the
reproducibilit y and accuracy of indirect digita l cephalometric radiographic analy sis.
University of Toronto, Faculty of Dentistry, Discipline of Orthodontics, Toronto, Canada
PAPER 2 FROM CHAPTER 3.
Cziraki SE, Pharoah MJ, Lawrence HP, Petrikowski CG, Birek P and Rossouw PE. The
reproducibility and accuracy of cephalometric analysis using conventional film and direct
digital images obtained by the storage phosphor technique.
University of Toronto, Faculty of Dentistry, Discipline of Orthodontics, Toronto, Canada
ABSTRACT 1 FROM THESIS ABSTRACTO
Cziraki SE, Pharoah MJ, Lawrence HP, Petrikowski CG, Birek P and Rossouw PE.
The reproducibility and accuracy of cephalornetric analysis using different digital
imaging modalities and image compression.
University of Toronto, Faculty of Dentistry, Discipline of Orthodontics, Toronto, Canada
AWARDS AND GRANTS
Graduate Research Day Award
Second Place, Best Poster Presentation
Faculty of Dentistry, University of Toronto
2000 Faculty of Dentistry Research Grant
1999-2000 Ontario Graduate Scholarship
Faculty of Dentistry, University of Toronto
SCIENTIFIC POSTER BOARD PRESENTATIONS
TITLE: The reproducibüity and accuracy of cephalometric analysis using different
imaging modaüties and image compression.
September 200 1 Canadian Association of Orthodontists
Annuai Meeting, Quebec City
May 200 1 Arnerican Association of Orthodontists
10 1 Annual Meeting, Toronto
March 2001 International Association for Dental Research (IADR)
Annual Meeting, Chicago, Ill.
February 200 1 Graduate Research Day, Faculty of Dentistry
Annual Meeting, Toronto
TABLE OF CONTENTS
ACKNOWLEDGEMENTS ...................................................................... iv
.............................................................................................
PREFACE v
.................................................................................
Thesis Format v
..............................................
Publications that will arise fiom this thesis v
..........................................................................
Awards and Grants vi
....................................................
Scientific Poster Board Presentations
........................................................................... v.i.
Table of Contents VII
.................................................................................
List of Tables
............................................................................. x..
List of Figures .XII
........................................................................
List of Appendices xiv
......................................................
CHAPTER 1: LITERATURE REVIEW 1
.................................................................................
Introduction -2
.......................................................
Direct Digital Imaging Techniques 3
............................................................
Charged Couple Device 3
Storage Phosphor Technique. ....................................................- 3
....................................................
Indirect Digital Imaging Techniques 4
............................................................................
Scanners -4
....................................................................
Video Cameras -4
............................................................
Understanding Digital Imaging 6
....................................................................
Optical Density -6
.......................................................................
Image Display 7
..................................................................
Spatial Resolution 8
.............................................
Digital Imaging in Medicine and Dentistry 8
..............................................
Digital Image Archiving and Compression 9
...............................................................
IPEG Compression 12
...............................................
Orthodontic Cephalometric Radiography 14
........................................
Digital Imaging in Otthodontic Cephalometry 16
...................................................................
Review of the Literature 17
..................................................................
Statement of the Problem 25
.......................................................................
Purpose of the Study 26
...........................................................................
Nul1 Hypotheses -26
vii
CHAPTER 2: INDIRECT DIGITAL IMAGLNG AND FILE COMPRESSION ....3 0
Impact of irreversible Joint Photographie Experts Group (JPEG) compression on the
reproducibility and accuracy of indirect digital cephalomehic radiographs
ABSTRACT ................................................................................... -31
...........................................................................
INTRODUCTION -33
...........................................................
MATERIALS AND METHODS 38
.............................................................................
The Equipment 38
.
Part 1
.......................
Radiographic Sample: lndirect DI versus Conventional Film 39
.........
Landmark identification protocol: Indirect DI versus Conventional Film 39
.
Part 2
...............
Radiographie Sample: JPEG compression of indirect digital image 41
...............................
Landmark identification protocol (JPEG compression) 41
.............................................................................
Data Treatment 42
Part 1. Indirect digital image versus conventional film .......................4 2
Part 2 . JPEG compressed (Q2 and 47) versus non-compressed (TIFF) ...4 3
.......................................................................................
RESCILTS 44
IntraClass Correlation Coefficient for Indirect DI versus conventional images.4
........................................................
Intra-examiner Reliability 44
........................................................
inter-examiner Reliability 44
..................................................
Intra-modality Reproducibility 44
..................................................
Inter-modality Reproducibility 45
........................................................
Inter-modality Accuracy -46
Compression of Indirect Digital Image Files Using JPEC Q2 and 47. ............. 47
......................................................
Intra-Image Reproducibility 47
......................................................
Inter-image Reproducibilit y 48
............................................................
Inter-Image Accuracy 49
..................................................................................
DISCUSSION 51
....................................................................
IntraClass Correlation Sl
................................................................................
Hard Tissues 52
.............................................................................
Dental Tissues -53
.....................................................................
X versus y-coordinates 53
............................................
Surnmary of Landmark Identification Error 54
............................................................
Cephalometric Measurements 54
........................
Patteni of Distribution of Error for Landmark Identification 55
.............................................................................
CONCLUSIONS -57
..............................................
CHAPTER 3: DIRECT DIGITAL IMAGING 72
The reproducibility and accuracy of cephalometric analysis using conventional
radiographie film and direct digital images obtained by the storage phosphor
.
technique
ABSTRACT ................................................................................... -73
...........................................................................
INTRODUCTION -74
MATERIALS AND METHODS ............................................................ 77
.............................................................................
The equipment -77
.............................................................................
Patient Sarnple -77
. . .
........................................................................
Image Acquisition -78
......................................................
Landmark Definition and Sampling 78
.......................................................................
Statistical Analysis -80
. .
....................................................................
Reproducibility 80
..........................................................................
Accuracy -80
......................................................................................
RESULTS -82
............................................................
Intra-modality reproducibility 82
Inter-modalit y reproducibilit y ............................................................ 83
...................................................................
Inter-modality accuracy 83
.................................................................................
DISCUSSION -85
.............................................................................
CONCLUSIONS -90
.
....................................
C W F R4 DISCUSSION AND CONCLUSIONS 105
.............................................................................
DISCUSSION 106
. .
..........................................................
Direct Digital Imaging 107
..............................................................
Image Compression 110
.........................................................
Future Research Trends 113
.........................................................................
CONCLUSIONS 114
APPENDICES ................................................................................... -116
. ...........
Appendix 1 Lateral Cephalometric Landmark Location and Definitions 117
. ............................................................
Appendix 2 Glossary of Terms 122
. .......................
Appendix 3 Indirect digital imaging and file compression data 124
. ...................................................
Appendix 4 Direct digital imaging data 134