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Authors: Jurgen Fripp, Stuart Crozier, Simon K Warfield, Sebastien Ourselin Source: PHYSICS IN MEDICINE AND BIOLOGY 52 (2007) 16171631 Speaker: Yi-Chun Ke Adviser: Bo-Chi Lai Ku-Yaw Chang

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Outline Introduction Method Results Conclusion 2009/4/281

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Introduction Osteoarthritis (OA) Characterized changes in the structure degeneration of the cartilage tissue Magnetic Resonance Imaging(MRI ) non-invasively 2009/4/282 patella adipose tissue tibia femur muscle tissue

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Method point distribution model (PDM) 3D-statistical shape models (3D-SSM) 3D-active shape model(3D-ASM) Dice similarity coefficient(DSC) 2009/4/283

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Method point distribution model (PDM) 3D-statistical shape models (3D-SSM) 3D-active shape model(3D-ASM) Dice similarity coefficient(DSC) 2009/4/284

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Method point distribution model (PDM) Landmarking and obtaining correspondence Represent the shape of the bones 2009/4/285

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Method point distribution model (PDM) 3D-statistical shape models (3D-SSM) 3D-active shape model(3D-ASM) Dice similarity coefficient(DSC) 2009/4/286

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Method 3D-statistical shape models (3D-SSM) estimate the pose and shape individual SSM of each of the bones (patella, tibia and femur) combined knee SSM 2009/4/287 Affine

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Method point distribution model (PDM) 3D-statistical shape models (3D-SSM) 3D-active shape model(3D-ASM) Dice similarity coefficient(DSC) 2009/4/288

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Method 3D-active shape model(3D-ASM) two components SSM matching criteria (often an appearance model) two steps Deformation Shape restriction 2009/4/289

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Method shape constraints obtained from the small database are overly restrictive Disabling shape constraints Replacing BCI > 95% 2009/4/2810 3D ASM relax

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Method point distribution model (PDM) 3D-statistical shape models (3D-SSM) 3D-active shape model(3D-ASM) Dice similarity coefficient(DSC) 2009/4/2811

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Method Dice similarity coefficient(DSC) sensitivity = T P /(T P + F N ) specificity = T N /(T N + F P ) Dice similarity coefficient = 2T P /(2T P + F P + F N ) 2009/4/2812 TpTp FnFn FpFp TnTn

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Results 2009/4/2813

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Results 2009/4/2814

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Conclusion automatically segment the bones and accurately extract the BCI each segmentation taking approximately 20 min DSC of 0.96,0.96 and 0.89 (femur, tibia and patella) only 3.60% failing approach for automatic use in subsequent cartilage segmentation and quantitative analysis 2009/4/2815

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, , , ,2009 , , , ,2008 Jurgen Fripp, Stuart Crozier, Simon K Warfield, Sebastien Ourselin, PHYSICS IN MEDICINE AND BIOLOGY,52,2007,16171631 MRI http://www.cbshow.org.tw/internet/activity/mri/ http://www2.cmu.edu.tw/~anatomy/ctanatomy/MRI/index.html http://www.mobile01.com/topicdetail.php?f=311&t=468552 Shape Model Formulation http://www2.imm.dtu.dk/%7Eaam/main/node12.html 2009/4/2816