Dr. Felix W. Wehrli Profile

Dr. Felix W. Wehrli

Professor at Univ of Pennsylvania Health System

SPIE Involvement:

Author

Proceedings Article | 28 February 2009 Paper

Fast 3D registration of multimodality tibial images with significant structural mismatch

C. Rajapakse, M. Wald, J. Magland, X. Zhang, X. Liu, X. Guo, F. Wehrli

Proceedings Volume 7262, 72620O (2009) https://doi.org/10.1117/12.811753

KEYWORDS: Bone, Image registration, 3D image processing, Image segmentation, Image resolution, Signal to noise ratio, In vivo imaging, Spatial resolution, 3D modeling, Image processing algorithms and systems

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Proceedings Article | 18 March 2008 Paper

Statistical properties of spin noise in MRI

Tianhu Lei, Hee Kwon Song, Felix Wehrli, Timothy P. Roberts

Proceedings Volume 6913, 69130H (2008) https://doi.org/10.1117/12.772145

KEYWORDS: Signal to noise ratio, Magnetic resonance imaging, Magnetism, Molybdenum, Interference (communication), Spatial resolution, Statistical analysis, Microscopy, Radiology, Receivers

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Proceedings Article | 12 March 2008 Paper

Improved 3D skeletonization of trabecular bone images derived from in vivo MRI

Jeremy Magland, Felix Wehrli

Proceedings Volume 6916, 691618 (2008) https://doi.org/10.1117/12.771002

KEYWORDS: Bone, 3D image processing, Magnetic resonance imaging, In vivo imaging, Image processing, Binary data, 3D metrology, Signal to noise ratio, 3D modeling, Data acquisition

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Proceedings Article | 11 March 2008 Paper

Efficient 3D rigid-body registration of micro-MR and micro-CT trabecular bone images

C. Rajapakse, J. Magland, S. Wehrli, X. Zhang, X. Liu, X. Guo, F. Wehrli

Proceedings Volume 6914, 69142Z (2008) https://doi.org/10.1117/12.770931

KEYWORDS: Image registration, 3D image processing, Bone, Image segmentation, Image resolution, In vivo imaging, Tomography, 3D modeling, Magnetism, Matrices

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Proceedings Article | 13 March 2006 Paper

Micro-MRI-based image acquisition and processing system for assessing the response to therapeutic intervention

B. Vasilić, G. Ladinsky, P. Saha, F. Wehrli

Proceedings Volume 6143, 61430W (2006) https://doi.org/10.1117/12.656650

KEYWORDS: Signal to noise ratio, Bone, Image registration, Image segmentation, Image processing, Image quality, Magnetic resonance imaging, Motion measurement, Error analysis, Data acquisition

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Proceedings Article | 29 April 2005 Paper

Cerebrovascular plaque segmentation using object class uncertainty snake in MR images

Bipul Das, Punam Saha, Ronald Wolf, Hee Kwon Song, Alexander Wright, Felix Wehrli

Proceedings Volume 5747, (2005) https://doi.org/10.1117/12.596150

KEYWORDS: Image segmentation, Arteries, Magnetic resonance imaging, In vivo imaging, Data modeling, Fuzzy logic, Radiology, Blood, Neck, Image processing algorithms and systems

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Atherosclerotic cerebrovascular disease leads to formation of lipid-laden plaques that can form emboli when ruptured causing blockage to cerebral vessels. The clinical manifestation of this event sequence is stroke; a leading cause of disability and death. In vivo MR imaging provides detailed image of vascular architecture for the carotid artery making it suitable for analysis of morphological features. Assessing the status of carotid arteries that supplies blood to the brain is of primary interest to such investigations. Reproducible quantification of carotid artery dimensions in MR images is essential for plaque analysis. Manual segmentation being the only method presently makes it time consuming and sensitive to inter and intra observer variability. This paper presents a deformable model for lumen and vessel wall segmentation of carotid artery from MR images. The major challenges of carotid artery segmentation are (a) low signal-to-noise ratio, (b) background intensity inhomogeneity and (c) indistinct inner and/or outer vessel wall. We propose a new, effective object-class uncertainty based deformable model with additional features tailored toward this specific application. Object-class uncertainty optimally utilizes MR intensity characteristics of various anatomic entities that enable the snake to avert leakage through fuzzy boundaries. To strengthen the deformable model for this application, some other properties are attributed to it in the form of (1) fully arc-based deformation using a Gaussian model to maximally exploit vessel wall smoothness, (2) construction of a forbidden region for outer-wall segmentation to reduce interferences by prominent lumen features and (3) arc-based landmark for efficient user interaction. The algorithm has been tested upon T1- and PD-weighted images. Measures of lumen area and vessel wall area are computed from segmented data of 10 patient MR images and their accuracy and reproducibility are examined. These results correspond exceptionally well with manual segmentation completed by radiology experts. Reproducibility of the proposed method is estimated for both intra- and inter-operator studies.

Proceedings Article | 14 April 2005 Paper

Predicting mechanical competence of trabecular bone using 3D tensor-scale-based parameters

Punam Saha, Michael Wald, Alex Radin, Felix Wehrli

Proceedings Volume 5746, (2005) https://doi.org/10.1117/12.596161

KEYWORDS: Bone, Anisotropy, 3D image processing, In vivo imaging, Signal to noise ratio, Statistical analysis, Image processing, Spatial resolution, Machine vision, Computer vision technology

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Proceedings Article | 14 April 2005 Paper

Study of trabecular bone microstructure using spatial autocorrelation analysis

Michael Wald, Branimir Vasilic, Punam Saha, Felix Wehrli

Proceedings Volume 5746, (2005) https://doi.org/10.1117/12.596133

KEYWORDS: Bone, Anisotropy, In vivo imaging, 3D image processing, Image resolution, 3D metrology, Image segmentation, Magnetic resonance imaging, Signal to noise ratio, Fourier transforms

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Proceedings Article | 12 May 2004 Paper

Object class uncertainty induced snake with applications to medical image segmentation

Bipul Das, Punam Saha, Felix Wehrli

Proceedings Volume 5370, (2004) https://doi.org/10.1117/12.535547

KEYWORDS: Image segmentation, Medical imaging, Brain, Visualization, Medical imaging applications, Magnetic resonance imaging, 3D modeling, Fuzzy logic, Image processing, Binary data

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Proceedings Article | 30 April 2004 Paper

In vivo assessment of trabecular bone architecture via three-dimensional tensor scale

Punam Saha, Felix Wehrli

Proceedings Volume 5369, (2004) https://doi.org/10.1117/12.535352

KEYWORDS: Bone, 3D image processing, In vivo imaging, Image segmentation, Anisotropy, Image processing, Medical imaging, Image classification, Binary data, Magnetic resonance imaging

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Proceedings Article | 15 May 2003 Paper

Quantification of trabecular bone anisotropy by means of tensor scale

Punam Saha, Felix Wehrli

Proceedings Volume 5032, (2003) https://doi.org/10.1117/12.481884

KEYWORDS: Anisotropy, Bone, In vivo imaging, Image resolution, Image segmentation, Image processing, Magnetic resonance imaging, 3D image processing, Tissues, Image compression

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Proceedings Article | 9 May 2002 Paper

Method for quantitative assessment of atherosclerotic lesion burden on the basis of high-resolution black-blood MRI

Jeffrey Duda, Hee Song, Ronald Wolf, Alex Wright, James Gee, Felix Wehrli

Proceedings Volume 4684, (2002) https://doi.org/10.1117/12.467154

KEYWORDS: Arteries, Magnetic resonance imaging, Signal to noise ratio, Image processing, Scanning electron microscopy, Tissues, Image segmentation, Binary data, Algorithm development, Error analysis

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Proceedings Article | 9 May 2002 Paper

Novel theory and algorithm for fuzzy distance transform and its applications

Punam Saha, Bryon Gomberg, Felix Wehrli

Proceedings Volume 4684, (2002) https://doi.org/10.1117/12.467094

KEYWORDS: Fuzzy logic, Bone, Image segmentation, 3D image processing, Algorithms, Digital imaging, Binary data, Image resolution, Raster graphics, Medical imaging

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Proceedings Article | 1 July 1991 Paper

Signa Tutor: results and future directions

Debra Rundle, Carolyn Watson, Sridhar Seshadri, Felix Wehrli

Proceedings Volume 1446, (1991) https://doi.org/10.1117/12.45294

KEYWORDS: Image display, Magnetic resonance imaging, Medical imaging, Picture Archiving and Communication System, Image acquisition, Scanners, Databases, Surgery, Data acquisition, Control systems

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Proceedings Article | 1 August 1990 Paper

MRI simulator: a teaching tool for radiology

Debra Rundle, Sheel Kishore, Sridhar Seshadri, Felix Wehrli

Proceedings Volume 1234, (1990) https://doi.org/10.1117/12.18943

KEYWORDS: Magnetic resonance imaging, Radiology, Scanners, Image acquisition, Databases, Imaging systems, Medical imaging, Tissues, Image restoration, Standards development

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Showing 5 of 15 publications

Conference Committee Involvement (5)

Biomedical Applications in Molecular, Structural, and Functional Imaging

8 February 2009 | Lake Buena Vista (Orlando Area), Florida, United States

Physiology, Function, and Structure from Medical Images

17 February 2008 | San Diego, California, United States

Physiology, Function, and Structure from Medical Images

18 February 2007 | San Diego, CA, United States

Physiology, Function, and Structure from Medical Images

12 February 2006 | San Diego, California, United States

Physiology, Function, and Structure from Medical Images

13 February 2005 | San Diego, California, United States

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