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Contributions to the study of coronary arteries in CTA images

Contributions to the study of coronary arteries in CTA images

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Master's Project Defense Master's Project Defense Presentation Transcript

  • Master EEAP Systems and Images Contributions to the Study of Coronary Arteries in CTA Images Supervisors: Maciej Orkisz, CREATIS Marcela Hernández, UniAndes Ricardo A. Corredor
  • Conservative Workflow Challenges Related Work Introduction Medical Context and Motivation 2 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 3 HEALTHY STENOTIC Left, Jeferson University Hospitals. Right, Schaap, 2010. 39% 30% 27% 4% Deaths caused by non- communicable diseases Cardiovascular system Respiratory and digestive systems Cancer Others Arterial diseases remain as one of the main causes of death in the world. Global status report on non-communicable diseases 2010 Medical Context and Motivation INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 4 HEALTHY STENOTIC Left, Jeferson University Hospitals. Right, Schaap, 2010. 39% 30% 27% 4% Deaths caused by non- communicable diseases Cardiovascular system Respiratory and digestive systems Cancer Others Arterial diseases remain as one of the main causes of death in the world. Global status report on non-communicable diseases 2010 Aorta Ostia Lumen Medical Context and Motivation LCA LAD LCX RCA INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 5 HEALTHY STENOTIC Left, Jeferson University Hospitals. Right, Schaap, 2010. 39% 30% 27% 4% Deaths caused by non- communicable diseases Cardiovascular system Respiratory and digestive systems Cancer Others Arterial diseases remain as one of the main causes of death in the world. Global status report on non-communicable diseases 2010 Medical Context and Motivation INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 6 Workflow INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Challenges - Size of data: 512 x 512 x 250 voxels (Resolution 0.3 x 0.3 x 0.4 mm) - Arteries diameters (1 – 7 mm) - Image artifacts (heart movement, noise,…) - Contrast attenuation, anomalies, presence of structures with similar intensities. - Shape variability (intra- and inter-patient) 7 Planes orthogonal to the central axis near the ostium (top), with a calcification (middle), and in a distal zone (bottom) INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • - Complete synthetic review (Lesage et al., 2009 ) Related Work - Recent doctoral studies (Zuluaga, 2011, Wang, 2011, Schaap, 2010, Lesage, 2009) + A priori knowledge about vessels + Vascular features + Lumen segmentation methods * With an axis * Without an axis INTRODUCTION PROPOSAL RESULTS CONCLUSIONS 8Contributions to the Study of Coronary Arteries in CTA Images
  • Related Work Lumen segmentation - Region growing (Bouraoui et al. 2008, Tek et. al. 2011, Metz et al. 2007) - Deformable models (shape prior, penalize leakages) (Nain et. al. 2004) - Linear and non-linear regression (Schaap et al. 2011) - Minimum cost-path (Zhu et.al. 2011) INTRODUCTION PROPOSAL RESULTS CONCLUSIONS 9 Preprocessing - Enhance vessels (Frangi et al. 1998, Zhou et. al., 2012, Zheng et al. 2011) - Define thresholds (Lesage et al. 2009, Tessmann et. al. 2011) - Define ROI and estimate artery radius (Carrillo et al. 2007, Zhou et. al. 2012, Xu et. al. 2012) Contributions to the Study of Coronary Arteries in CTA Images
  • Methods Results Proposal Materials 10 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Materials 11 Workshops MICCAI 2008 - Coronary Artery Tracking - 8 training annotated (axis + radius) datasets MICCAI 2012 - Stenoses Detection, Quantification and Lumen Segmentation - 18 training annotated (reference axes + stenoses information) datasets INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Methods 12 -Radius Estimation  Linear regression (MICCAI 2008 radius data) - Axis Extraction (Tek + Dijkstra method) and Correction INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images Preprocessing
  • Methods 13 -Radius Estimation  Linear regression (MICCAI 2008 radius data) - Axis Extraction (Tek + Dijkstra method) and Correction INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images Preprocessing
  • Methods 14 - Validation scores - Classical approaches -Local region growing -Variational Region Growing -Active contours - Classification approaches - Support Vector Machines - K-means clustering INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images Segmentation
  • Methods 15 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images VP:=true positives VN:=true negatives FP :=false positives FN:=false negatives Segmentation Reference FN VP VN FP Validation scores
  • Classical Approaches 16 Local region growing (Kappa – Sigma clipping) ( - k,  + k), k = 2, 2.5, 3 Variational region growing (VRG) + vesselness (Pacureanu et al. 2010) Sphere Axis - Chan & Vese approach (homogeneous regions) Frangi et. al. 1998 Sato et. al. 1998 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Classical Approaches 17 Active contours - Lankton approach (Lankton et. al. 2007) based on: Geodesic active contours Region-based active contours + = INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Classification Approaches 18 Lumen features - Multi-scale analysis based on Gaussian filtering (Deriche et.al. 1993) - Eleven scales according to arteries radius - Hessian matrix eigenvalues - Gradient magnitude - Intensity TOTAL: 55 features by voxel INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Classification Approaches 19 Support Vector Machines - Kernel RBF (Chang et. al. 2011) - C: regularization constant - : kernel parameter Extraction of 3D features Classification strategy Annotated data Supervised learning Binary image White = artery CTA Image http://ccforum.com/content/11/4/R83/figure/F1 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • Classification Approaches 20 K-means clustering - K = 2 classes - Euclidean distance - +1 feature: distance from ostia Extraction of 3D features in spheres Classification strategy Unsupervised learning Binary image White = artery Axis extracted Spheres (Carrillo et. al. 2007) INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 21 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images VP:=true positives VN:=true negatives FP :=false positives FN:=false negatives Segmentation Reference FN VP VN FP Validation scores Results
  • 22 Results Radius Estimation Distance from ostia – RCA (mm) Radius(mm) INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 23 Results Before correction After correction Wrong corrections in bifurcations and plaques Axis correction INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 24 Results Local region growing Acceptable=9/15 Poor=4/15 Bad=2/15 VRG D: Using Frangi in mask B (Dice: 68.1%, Accuracy: 84.0%, Specificity: 85.6%, Sensitivity: 78.5%) E: Using Frangi in mask C -> High increase in FP INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 25 Results Active contours INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • 26 Results Low Dice score (45%) Support Vector Machines K-means clustering Dice score: 66.48% (Thresholding Dice: 65.20%) Reference Mask K-means result XOR INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • • Contributions in axis correction and lumen segmentation using five different techniques. • Additional problems found: - Lumen intensity can increase in a distal zone, specially after a plaque. - It can be higher than calcified plaques intensity. • Axis correction algorithm is sensitive to bifurcations and calcified plaques -> it can be used in detection of bifurcations. • Best results were obtained with region growing, clustering, and active contours. Poor results with SVM. A more detailed analysis of selected features is required. • Explicit modeling of coronary arteries and intensity profiles is still a challenging task. • A complete validation framework for coronary segmentation is required. Conclusions 27 INTRODUCTION PROPOSAL RESULTS CONCLUSIONS Contributions to the Study of Coronary Arteries in CTA Images
  • The end… Questions ?? 28Contributions to the Study of Coronary Arteries in CTA Images