Pew-Thian Yap, Ph.D.

Assistant Professor of Radiology, UNC-CH

 

Research

My major research interest lies in diffusion-weighted MRI (DW-MRI) and its application to the characterization of brain white matter connectivity. I have made vital technical contributions to human brain mapping by developing novel algorithms for spatial normalization of DW-MRI data, ranging from the popular Diffusion Tensor Imaging (DTI) to the high-precision High Angular Resolution Diffusion Imaging (HARDI). My current research focuses on the clinical application of these technical innovations, as well as the development of cutting-edge neuroimaging technologies. In particular, I have employed a fiber-based approach to characterize brain white-matter connectivity of pediatric subjects, giving fundamentally important neuropsychological insights into human brain development in the first years of life. Current efforts are being directed at extending this framework to incorporate information from different imaging modalities (structural MRI + functional MRI + DW-MRI), and applying this novel analysis paradigm to a number of important clinical studies, including Alzheimer's disease, schizophrenia, and multiple sclerosis, for both prognosis and diagnosis purposes.

Job Opportunities

EducationFrom The NIH Catalyst, Volume 3, page 23.

Post-Doctoral Research Associate
University of North Carolina at Chapel Hill, U.S.A.

Research Fellow
Nanyang Technological University, Singapore

Ph.D.
University of Malaya, Malaysia

 

Collaborators

 

Publications

Journal Articles

  1. Manhua Liu, P.-T. Yap, "Invariant Representation of Orientation Fields for Fingerprint Indexing," Pattern Recognition, accepted, 2012.

  2. Q. Wang, P.-T. Yap, G. Wu, D. Shen, "Application of Neuroanatomical Features to Tractography Clustering," Human Brain Mapping, accepted, 2012.

  3. J. Nie, L. Guo, K. Li, Y. Wang, G. Chen, L. Li, H. Chen, F. Deng, X. Jiang, T. Zhang, L. Huang, C. Faraco, D. Zhang, C. Guo, P.-T. Yap, X. Hu, G. Li, J. Lv, Y. Yuan, D. Zhu, J. Han, D. Sabatinelli, Q. Zhao, L. S. Miller, B. Xu, P. Shen, S. Platt, D. Shen, X. Hu, T. Liu, "Axonal Fiber Terminations Concentrate on Gyri," Cerebral Cortex, accepted, 2011.

  4. C.-Y. Wee, P.-T. Yap, D. Zhang, K. Denny, J. N. Browndyke, G.G. Potter, K.A. Welsh-Bohmer, L. Wang, D. Shen, "Identification of MCI Individuals Using Structural and Functional Connectivity Networks," NeuroImage, vol. 59, no. 3, pp. 2045-2056, 2012.

  5. M. Kim, G. Wu, P.-T. Yap, D. Shen, "A General Fast Registration Framework by Learning Deformation-Appearance Correlation," IEEE Transactions on Image Processing, accepted, 2011.

  6. L. Wang, F. Shi, P.-T. Yap, W. Lin, J. H. Gilmore, D. Shen, "Longitudinally Guided Level Sets for Consistent Tissue Segmentation of Neonates," Human Brain Mapping, accepted, 2011.

  7. P.-T. Yap, Y. Fan, Y. Chen, J. Gilmore, W. Lin, D. Shen, "Development Trends of White Matter Connectivity in the First Years of Life," PLoS ONE, vol. 6, no. 9, pp. e24678, 2011.

  8. H. Jia, P.-T. Yap, D. Shen, "Iterative Multi-Atlas-Based Multi-Image Segmentation with Tree-Based Registration," NeuroImage, vol. 59, no. 1, pp. 422-430, 2011.

  9. L. Zhou, Y. Wang, Y. Li, P.-T. Yap, D. Shen, "Hierarchical Anatomical Brain Networks for MCI Prediction: Revisiting Volumetric Measures," PLoS ONE, vol. 6, no. 7, pp. e21935, 2011.

  10. P.-T. Yap, J.H. Gilmore, W. Lin, D. Shen, "PopTract: Population-Based Tractography," IEEE Transactions on Medical Imaging, vol. 30, no. 10, pp. 1829 - 1840, 2011.

  11. F. Shi, P.-T. Yap, G.Wu, H. Jia, J.H. Gilmore, W. Lin, D. Shen, "Infant Brain Atlases from Neonates to 1- and 2-Year-Olds," PLoS ONE, vol. 6, no. 4, pp. e18746, 2011.

  12. P.-T. Yap, Y. Chen, H. An, Y. Yang, J. H. Gilmore, W. Lin, and D. Shen, "SPHERE: SPherical Harmonic Elastic REgistration of HARDI data," NeuroImage, vol. 55, no. 2, pp. 545-556, 2011.

  13. C.-Y. Wee*, P.-T. Yap*, W. Li, K. Denny, J.N. Brownyke, G.G. Potter, K.A. Welsh-Bohmer, L. Wang, D. Shen, "Enriched White-Matter Connectivity Networks for Accurate Identification of MCI Patients," NeuroImage, vol. 54, no. 3, pp. 1812-1822, 2011.

  14. H. Jia, P.-T. Yap, G.Wu, Q.Wang, D. Shen, "Intermediate Templates Guided Groupwise Registration of Diffusion Tensor Images," NeuroImage, vol. 54, no. 2, pp. 928-939, 2011.

  15. P.-T. Yap, G. Wu, D. Shen, "Human Brain Connectomics: Networks, Techniques and Applications," IEEE Signal Processing Magazine, vol. 27, no. 4, 131-134, 2010. (Invited Paper)

  16. P.-T. Yap, G. Wu, H. Zhu, W. Lin, D. Shen, "F-TIMER: Fast Tensor Image Morphing for Elastic Registration," IEEE Transactions on Medical Imaging, vol. 29, no. 5, pp. 1192-1203, 2010.

  17. P.-T. Yap, X. Jiang and A. C. Kot, "Two Dimensional Polar Harmonic Transforms for Invariant Image Representation," IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 32, no. 7, pp. 1259-1270, 2010.

  18. Q. Wang, G. Wu, P.-T. Yap, D. Shen, "Attribute Vector Guided Groupwise Registration," NeuroImage, vol. 50, no. 4, pp. 1485-1496, 2010.

  19. F. Shi, D. Shen, P.-T. Yap, Y. Fan, J.-Z. Cheng, H. An, L. L. Wald, G. Gerig, J. H. Gilmore, and W. Lin "CENTS: Cortical Enhanced Neonatal Tissue Segmentation," Human Brain Mapping, vol. 32, pp. 382-396, 2010.

  20. F. Shi, P.-T. Yap, Y. Fan, J. H Gilmore, W. Lin, D. Shen, "Construction of Multi-Region-Multi-Reference Atlases for Neonatal Brain MRI Segmentation," NeuroImage, vol. 51, no. 2, pp. 684-693, 2010.

  21. Q. Wang, L. Chen, P.-T. Yap, G. Wu, D. Shen, "Groupwise Registration Based on Hierarchical Image Clustering and Atlas Synthesis," Human Brain Mapping, vol. 31, no. 8, pp. 1128-1140, Jan. 2010.

  22. G. Wu, P.-T. Yap, D. Shen "TPS:HAMMER: Improving HAMMER Registration Algorithm by Soft Correspondence Matching and Thin-Plate Splines based Deformation Interpolation," NeuroImage, vol. 49, no. 3, pp. 2225-2233, February 2010.

  23. P.-T. Yap, G. Wu, H. Zhu, W. Lin, D. Shen, "TIMER: Tensor Image Morphing for Elastic Registration," NeuroImage, vol. 47, no. 2, pp. 549-563, 2009.

  24. P.-T. Yap, R. Paramesran, S.-H. Ong, "Image Analysis Using Hahn Moments," IEEE Transactions on Pattern Analysis and Machine Intelligence1, vol. 29, no. 11, pp. 2057-2062, November 2007.

  25. P.-T. Yap, R. Paramesran, "Eigenmoments," Pattern Recognition, vol. 40, no. 4, pp. 1234 - 1244, April 2007.

  26. P.-T. Yap, R. Paramesran, "Content-Based Image Retrieval Using Legendre Chromaticity Distribution Moments," IEE Proceedings on Vision, Image and Signal Processing, vol. 153, no. 1, pp. 17 - 24, February 2006.

  27. P.-T. Yap, R. Paramesran, "An Efficient Method for the Computation of Legendre Moments," IEEE Transactions of Pattern Analysis and Machine Intelligence, vol. 27, no. 12, pp. 1996-2002, December 2005.

  28. P.-T. Yap, R. Paramesran, "Image Focus Measure Based on Chebyshev Moments," IEE Proceedings on Vision, Image and Signal Processing, vol. 151, no. 2, pp. 128 - 136, April 2004.

  29. P.-T. Yap, R. Paramesran, "Image Analysis by Krawtchouk moments," IEEE Transactions on Image Processing, vol. 12, no. 11, pp. 1367-1377, November 2003.

* denotes equal contributions

 

Book Chapters

  1. M. Liu, X. Jiang, A. C. Kot, P.-T. Yap, "Application of Polar Harmonic Transforms to Fingerprint Classification," Emerging Topics in Computer Vision and its Applications, World Scientific Publishing, 2011.

  2. C.-Y. Wee, D. Zhang, L. Zhou, P.-T. Yap, D. Shen, "Machine Learning Techniques for AD/MCI Diagnosis and Prognosis," Machine Learning in Healthcare Informatics, Springer, 2011.

  3. G. Wu, H. Jia, Q. Wang, F. Shi, P.-T. Yap and D. Shen, "Emergence of Groupwise Registration in MR Brain Study," The Biomedical Engineering Handbook, Fourth Edition, 2010.

 

Full-Length Conference Papers

  1. L. Wang, F. Shi, P.-T. Yap, J. H. Gilmore, W. Lin, and D. Shen, "Accurate and Consistent 4D Segmentation of Serial Infant Brain MR Images," Multimodal Brain Image Analysis (MBIA 2011), MICCAI 2011, Toronto, Canada, Sep. 18, 2011.

  2. Q. Wang, P.-T. Yap, G. Wu, D. Shen, "Diffusion Tensor Image Registration with Combined Tract and Tensor Features," MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011. (MICCAI Student Travel Award)

  3. Q. Wang, P.-T. Yap, G. Wu, D. Shen, "Fiber Modeling and Clustering Based on Neuroanatomical Features." MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011.

  4. P.-T. Yap, J. H. Gilmore, W. Lin, D. Shen, "Reconstruction of Fiber Trajectories via Population-Based Estimation of Local Orientations," MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011. (Oral; Acceptance Rate: 4.2%) [poster] [slides]

  5. P.-T. Yap, J. H. Gilmore, W. Lin, D. Shen, "Longitudinal Tractography with Application to Neuronal Fiber Trajectory Reconstruction in Neonates," MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011.

  6. Y. Wang, J. Nie, P.-T. Yap, F. Shi, L. Guo, D. Shen, "Robust Deformable-Surface-Based Skull-Stripping for Large-Scale Studies," MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011. (MICCAI Student Travel Award; turned down due to conflicting travel plans)

  7. C.-Y. Wee, P.-T. Yap, D. Zhang, K. Denny, L. Wang, D. Shen, "Identification of Individuals with MCI via Multimodality Connectivity Networks," MICCAI 2011, Toronto, Canada, Sep. 18-22, 2011.

  8. L. Zhou, Y. Wang, Y. Li, P.-T. Yap, D. Shen, "Hierarchical Anatomical Brain Networks for MCI Prediction by Partial Least Square Analysis," CVPR 2011, Colorado Springs, U.S.A, Jun 21-23, 2011.

  9. Y. Wang, P. Chastain, P.-T. Yap, J.-Z. Cheng, D. Kaufman, L. Guo, D. Shen, "Automated DNA Fiber Tracking and Measurement," ISBI 2011, Chicago, Illinois, U.S.A, Mar 30-Apr 2, 2011.

  10. M. Kim, G. Wu, P.-T. Yap, D. Shen, "A Generalized Learning Based for Fast Brain Image Registration," MICCAI 2010, Beijing, China, Sep. 20-24, 2010.

  11. C.-Y. Wee, P.-T. Yap, J.N. Brownyke, G.G. Potter, D.C. Steffens, K. Welsh-Bohmer, L. Wang, D. Shen, "Accurate Identification of MCI Patients via Enriched White-Matter Connectivity Network," MLMI, MICCAI 2010, Beijing, China, Sept. 20-24, pp. 140-147, 2010.

  12. P.-T. Yap, Y. Chen, H. An, J.H. Gilmore, W. Lin, D. Shen, "Hierachical Spherical Harmonics Based Deformable HARDI Registration," MIAR 2010, Beijing, China, Sep. 19-20, 2010.

  13. F. Shi, P.-T. Yap, J.H. Gilmore, W.i Lin, D. Shen, "Spatial-Temporal Constraint for Segmentation of Serial Infant Brain MR Images," MIAR 2010, Beijing, China, Sep. 19-20, 2010.

  14. Q. Wang, P.-T. Yap, H. Jia, G. Wu, D. Shen, "Hierarchical Fiber Clustering Based on Multi-Scale Neuroanatomical Features," MIAR 2010, Beijing, China, Sep. 19-20, 2010.

  15. F. Shi, P.-T. Yap, Y. Fan, J. H. Gilmore, W. Lin, and D. Shen, "Neonatal Brain MRI Segmentation by Building Multi-Region-Multi-Reference Atlases," ISBI 2010, Rotterdam, The Netherlands, Apr. 14-17, 2010. (Oral)

  16. G. Wu, P.-T. Yap, Q. Wang, and D. Shen, "Groupwise Registration from Exemplar to Group Mean: Extending HAMMER to Groupwise Registration," ISBI 2010, Rotterdam, The Netherlands, Apr. 14-17, 2010.

  17. Q. Wang, P.-T. Yap, G. Wu, D. Shen, "Attribute Vector Guided Groupwise Registration," MICCAI 2009, London, UK, Sept. 20 to 24, 2009.

  18. P.-T. Yap, G. Wu, H. Zhu, W. Lin, D. Shen, "F-TIMER: Fast Tensor Morphing for Elastic Registration," MICCAI 2009, London, UK, Sept. 20 to 24, 2009.

  19. F. Shi, P.-T. Yap, Y. Fan, J. Cheng, L. L. Wald, G. Gerig, W. Lin, D. Shen, "Cortical Enhanced Tissue Segmentation of Neonatal Brain MR Images Acquired by a Dedicated Phased Array Coil," MMBIA 2009, Miami Beach, Florida, June 20th, 2009.

  20. S. Tang, Y. Fan, H. Zhu, P.-T. Yap, W. Gao, W. Lin, D. Shen, "Regularization of Diffusion Tensor Field Using Coupled Robust Anisotropic Diffusion," MMBIA 2009, Miami Beach, Florida, June 20th, 2009.

  21. P.-T. Yap, G. Wu, H. Zhu, W. Lin, D. Shen, "TIMER: Tensor Image Morphing for Elastic Registration," MMBIA 2009, Miami Beach, Florida, June 20th, 2009. (Oral)

  22. P.-T. Yap, X. Jiang, A. C. Kot, "Boosted Complex Moments for Discriminant Rotation Invariant Object Recognition," in Proceedings of ICPR, December 8-11, 2008. pp. 1-4. (Oral)

  23. P.-T. Yap, X. Jiang, A. C. Kot, "LDA Enhanced Moments," in Proceedings of ICICS, December 2007. (Oral)

  24. P.-T. Yap and R. Paramesran, "An Image Watermarking Scheme Based on Orthogonal Moments," in Proceedings of TENCON, November 2005, pp. 1-4.

  25. P.-T. Yap and R. Paramesran, "Image Watermarking Using Tchebichef Moments," in Proceedings of TECHPOS, December 2004.

  26. P.-T. Yap and R. Paramesran, "Jacobi Moments as Image Features," in Proceedings of TENCON, November 2004, pp. 594-597.

  27. P.-T. Yap and R. Paramesran, "Local Watermarks Based on Krawtchouk moments," in Proceedings of TENCON, November 2004, pp. 73-76. (Oral, Awarded Travel Grant)

  28. P.-T. Yap and R. Paramesran, "Chebyshev Polynomials Based Moment Invariants With High Noise Tolerance," in Proceedings of M2USIC, 2003, pp. 123-126.

  29. P.-T. Yap and R. Paramesran, "Image Compression Using Discrete Tchebichef Transform With Zonal Coding," in Proceedings of AIAI, June 2003.

  30. P.-T. Yap and R. Paramesran, "Adaptive Feature Extraction Using Dual Hahn Moments," in Proceedings of AIAI, June 2003.

  31. P.-T. Yap and R. Paramesran, "Racah Moments as Image Features," in Proceedings of Integrating Technology in the Mathematical Sciences, 2003.

  32. P.-T. Yap and R. Paramesran, "A New Framework for Image Representation Using Discrete Orthogonal Moments," in Proceedings of TECHPOS, 2002, pp. 309-313.

  33. P.-T. Yap and R. Paramesran, "Image Restoration of Noisy Images Using Tchebichef moments," in Proceedings of Asia-Paci c Conference on Circuits and Systems, APCCAS, 2002, vol. 2, pp. 525 -528.

  34. P.-T. Yap, R. Paramesran, and S.-H. Ong, "Krawtchouk Moments as a New Set of Moments for Image Reconstruction," in Proceedings of IJCNN, 2002, vol. 1, pp. 908 -912.

  35. P.-T. Yap, R. Paramesran, and S.-H. Ong, "Chebyshev Moments as a New Set of Moments for Image Reconstruction," in Proceedings of IJCNN, 2001, vol. 4, pp. 2856 -2860. (Awarded Travel Grant)

 

Meeting Abstracts

  1. F. Shi, G. Wu, P.-T. Yap, H. Jia, J. H. Gilmore, W. Lin, D. Shen, "Infant 0-1-2 Brain Atlases for MRI Segmentation and Normalization," ISMRM'11, Montreal, Quebec, Canada, May 7-13, 2011. (Best Poster Award; Human Brain Disorders - Neuro 1)

  2. F. Shi, P.-T. Yap, J. K. Smith, K. S. Giovanello, C. Goerger, W. Lin, K. M. Guskiewicz, D. Shen, "Disrupted Anatomical Brain Connectivity in Retired Professional Football Players," ISMRM'11, Montreal, Quebec, Canada, May 7-13, 2011. (Oral)

  3. C.-Y. Wee, P.-T. Yap, L. Wang, D. Shen, "Classification of MCI Patients via Functional Connectivity Networks," ISMRM'11, Montreal, Quebec, Canada, May 7-13, 2011.

  4. P.-T. Yap, J. H. Gilmore, W. Lin, D. Shen, "Accurate Estimation of Local Fiber Orientations for Groupwise Tractography," ISMRM'11, Montreal, Quebec, Canada, May 7-13, 2011.

  5. C.-Y. Wee, P.-T. Yap, J.N. Browndyke, G.G. Potter, D.C. Steffens, K.A. Welsh-Bohmer, L. Wang and D. Shen, "Accurate Identification of MCI Patients Using Multivariate White-Matter Connectomics," 96th RSNA Scientific Assembly and Annual Meeting, Chicago, Nov. 28-Dec. 3, 2010.

  6. P.-T. Yap, Y. Fan, Y. Chen, J. Gilmore, W. Lin, D. Shen, "Exploring Developmental Structural Connectivity Patterns by In Vivo Diffusion Tensor Imaging Tractography on Longitudinal Pediatric Data," ISMRM2010, Stockholm, Sweden, 1-7 May, 2010.

  7. P.-T. Yap, Y. Chen, H. An, J. Gilmore, W. Lin, D. Shen, "Non-Parametric Deformable Registration of High Angular Resolution Diffusion Data Using Diffusion Profile Statistics," ISMRM2010, Stockholm, Sweden, 1-7 May, 2010.

  8. P.-T. Yap, Y. Chen, H. An, J. Gilmore, W. Lin, D. Shen, "Fast Feature-Based Multi-Scale Registration of HARDI Data Using Fourth Order Tensors," ISMRM2010, Stockholm, Sweden, 1-7 May, 2010.

  9. F. Shi, Y. Fan, P.-T. Yap, W. Lin, J. Gilmore, D. Shen, "Altered small-world properties in newborns at high risk for schizophrenia," ISMRM2010, Stockholm, Sweden, 1-7 May, 2010.

  10. W. Gao, P.-T. Yap, H. Zhu, K. Giovanello, K. Smith, J. Gilmore, and W. Lin, "The Functional-Structural Interplay During First Two Years' Brain Development," ISMRM2010, Stockholm, Sweden, 1-7 May, 2010. (Oral)

  11. F. Shi, P.-T. Yap, Y. Fan, J. Gilmore, W. Lin, D. Shen, "Construction of Probabilistic Atlases for Neonates and One-year-olds," RNSA09, November 29-December 4, Chicago, 2009.

  12. P.-T. Yap, G. Wu, H. Zhu, W. Lin, D. Shen, "F-TIMER: Fast Tensor Image Morphing for Elastic Registration," RNSA09, November 29-December 4, Chicago, 2009. (Oral)

  13. P.-T. Yap, H. Zhu, W. Lin, D. Shen, "Hierarchical Di usion Tensor Image Registration Based on Tensor Regional Distributions," ISMRM09, Hawaii, April 18-24, 2009.

IDEA @ UNC-CH

ptyap at med dot unc dot edu

Updated: Feb 4, 2011