compare with one point measure.ppt
TRANSCRIPT
Measurement of Mandibular Cortical Width on Dental Panoramic Radiograph
Objective
To develop a computer aided system for measuring mandibular cortical width between the margins of cortical bone continuously on dental panoramic radiograph ,and clarify the diagnostic efficacy of the system
Femoral neck
Lumbar spine
Normal
Porous
Schematic Diagram of measuring cortical width
I.Region of Interest determination
a.Contrast Stretchingb.Determining mental foramenc. cropping area around mental foramen
II. Image Enhancement
a. Thresholding Algorithmb. High pass filtering
III. Cortical margin Identificationa. Distance Functionb.Thresholdingc.Closing and Openingd.Distance Functione. Inverting imagef. Dynamic Programmingg. Maskingh. Inserting DiscI. Finding upper and lower boundary
IV.Distance Measurement
a.Smoothingb. Polynomial Function
RightLeft
Contrasting ImageOriginal Image
Right
Distance functionHigh pass Filter
Closing &opening
Thresholding
Thresholding Filtering
Distance Function Inverting Image Dynamic Programming
Smooth & Tangentline Disc Fitting Masking
Distance functionHigh pass Filter
Filtering
ThresholdingThresholding
Closing &opening Thresholding
Left
Distance Function Masking
Disc FittingSmooth&Tangent
No. Image Right Left
1 1.tif 53.16 49.78
2 2.tif 37.28 26.12
3 3.tif 72.59 83.57
4 4.tif 39.87 38.56
5 5.tif 48.13 49.37
6 6.tif 57.49 56.28
7 7.tif 43.73 41.37
8 8.tif 30.01 30.61
9 9.tif 35.85 38.97
10 10.tif 39.70 39.27
11 11.tif 39.58 33.61
12 12.tif 32.09 40.97
13 14.tif 48.48 42.03
14 15.tif 47.34 39.92
No. Image Right Left
15 16.tif 35.59 36.22
16 17.tif 42.25 55.90
17 18.tif 28.12 30.18
18 19.tif 26.79 26.48
19 20.tif 49.20 51.54
20 21.tif 19.22 27.31
21 22.tif 27.93 34.43
22 35.tif 54.70 45.35
23 61.tif 22.05 25.31
24 62.tif 25.78 25.61
25 84.tif 27.23 30.13
Results- cortical width by pixels
Image Cortical Erosion
Cortical Width
1.tif 1 4.26
2.tif 3 2.22
3.tif 1 4.27
4.tif 1 6.04
5.tif 2 3.84
6.tif 1 4.66
7.tif 1 4.12
8.tif 2 3.42
9.tif 1 3.88
10.tif 2 4.63
11.tif 1 3.95
12.tif 2 3.07
14.tif 2 3.47
15.tif 1 6.48
16.tif 1 4.33
17.tif 1 4.9
18.tif 2 2.81
Image Cortical Erosion
Cortical Width
19.tif 1 2.57
20.tif 1 3.14
21.tif 3 2.39
22.tif 2 4.25
35.tif 2 3.94
61.tif 2 3.05
62.tif 1 4.33
84.tif 2 4.29
Previous Results
Computer-aided system
Right cortical width
Left cortical width
Threshold (pixels)
Sensitivity %
Specificity %
Threshold (pixels)
Sensitivity %
Specificity %
Lumbar spine 40 90 60 40 90 60
Femoral 37.5 80 73.3 41 90 53.3
Correlation of Computer-aided system with lumbar spine and femoral bone
Right cortical Left
Lumbar spine 0.47 0.65
Femoral 0.4 0.55
Right cortical Left
Lumbar spine 0.41 0.67
Femoral 0.44 0.58
Correlation of Manual measurement with lumbar spine and femoral bone