Dr. Kenneth R. Hoffman Profile

Dr. Kenneth R. Hoffman

Professor at Canon Stroke and Vascular Research Ctr

SPIE Involvement:

Author

Publications (61)

Proceedings Article | 17 March 2011 Paper

Determination of 3D flow velocity distributions from single-plane angiographic sequences

Kenneth Hoffmann, Todd Dorazio, Joseph Lee, Jae-Hun Jung, E. Bruce Pitman, Alan Walczak, Xinjuan Chen

Proceedings Volume 7961, 79613S (2011) https://doi.org/10.1117/12.877792

KEYWORDS: Angiography, 3D acquisition, Signal to noise ratio, 3D imaging standards, Computer simulations, 3D modeling, Data acquisition, Medical imaging, Data conversion, Error analysis

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Proceedings Article | 23 March 2010 Paper

Off-center object of interest (OOI) imaging in filtered region of interest rotational angiography (FROI-RA)

Sebastian Schafer, Peter Noël, Alan Walczak, Andrew Kuhls-Gilcrist, Kenneth Hoffmann

Proceedings Volume 7622, 76223F (2010) https://doi.org/10.1117/12.844011

KEYWORDS: Image filtering, Angiography, X-rays, Image quality, Signal to noise ratio, Signal attenuation, X-ray imaging, Data centers, Data acquisition, Physics

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Proceedings Article | 27 March 2009 Paper

Reconstruction from a flexible number of projections in cone-beam computed tomography via active shape models

Peter Noël, Jason Corso, Jinhui Xu, Kenneth Hoffmann, Sebastian Schafer, Alan Walczak

Proceedings Volume 7259, 725949 (2009) https://doi.org/10.1117/12.811751

KEYWORDS: Reconstruction algorithms, Computed tomography, Image segmentation, Data modeling, Digital mammography, Sensors, Shape analysis, Angiography, X-rays, Bismuth

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Proceedings Article | 14 March 2009 Paper

Modification of the NEMA XR21-2000 cardiac phantom for testing of imaging systems used in endovascular image guided interventions

C. Ionita, A. Dohatcu, A. Jain, C. Keleshis, K. Hoffmann, D. Bednarek, S. Rudin

Proceedings Volume 7258, 72584R (2009) https://doi.org/10.1117/12.813533

KEYWORDS: Iodine, Arteries, X-ray imaging, Aluminum, X-rays, Angiography, Fluoroscopy, Imaging systems, Head, Lead

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Proceedings Article | 14 March 2009 Paper

High-contrast artifact reduction in cone beam computed tomography by using geometric techniques

Peter Noël, Jinhui Xu, Kenneth Hoffmann, Jason Corso, Sebastian Schafer, Alan Walczak

Proceedings Volume 7258, 72583A (2009) https://doi.org/10.1117/12.811679

KEYWORDS: Reconstruction algorithms, Computed tomography, Sensors, Image quality, Metals, Visibility, CT reconstruction, Computer simulations, X-rays, Diagnostics

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Proceedings Article | 14 March 2009 Paper

Real time implementation of distortion corrections for a tiled EMCCD-based solid state x-ray image intensifier (SSXII)

Christos Keleshis, K. Hoffmann, J. Lee, H. Hamwi, W. Wang, C. Ionita, D. Bednarek, A. Verevkin, S. Rudin

Proceedings Volume 7258, 72583B (2009) https://doi.org/10.1117/12.813603

KEYWORDS: Distortion, Sensors, Electron multiplying charge coupled devices, Computer simulations, X-rays, X-ray imaging, Image intensifiers, Fiber optics, Image quality, Image processing

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Proceedings Article | 13 March 2009 Paper

Toward region of interest computer tomography

Sebastian Schafer, Peter Noël, Alan Walczak, Kenneth Hoffmann

Proceedings Volume 7258, 72582N (2009) https://doi.org/10.1117/12.811542

KEYWORDS: Image filtering, X-rays, Signal attenuation, Angiography, Computed tomography, X-ray imaging, Head, X-ray computed tomography, Gadolinium, Tomography

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Computed Tomography (CT) is widely used in the modern clinical settings. In certain procedures, the region of interest (ROI) is often considerably smaller than the imaged field of view (FOV), thereby subjecting the patient to extra dose. For these procedures, we propose a method of filtered region-of-interest (FROI) CT. In this procedure, a predetermined ROI is imaged with standard x-ray intensity, while surrounding areas are imaged using a substantial lower x-ray intensity by interposing an x-ray attenuator in the beam. For the FROI-CT acquisitions in this study, a gadolinium filter with a circular central opening is placed in the x-ray beam of a standard clinical rotational angiography system. The resulting image contains a high intensity ROI, a low intensity region surrounding the ROI, and a transition region between these two. Three-dimensional reconstruction using these images would result in artifacts. Therefore, the intensities in the images are equalized prior to reconstruction. To equalize the intensities, first two images are obtained, one unfiltered and one with a filter in place. The corresponding data in the two images are used in a linear least-squares fit to determine the equalization function. The transition region is equalized using a radial filter technique, based on a comparison of the data on either side of the transition region after intensity equalization. The technique was evaluated using rotational angiographic sequences of a head phantom obtained with and without the filter in place. Differences between conventional (unfiltered) and FROI-equalized images of the head phantom were approximately 5%. Differences in reconstructed images (conventional and FROI) were 7% on average inside the reconstructed ROI. These results are comparable to those obtained for two separate standard acquisitions. A 50% dose reduction was obtained for a 50% FOV radius for the filter. These results indicate that FROI-CT can provide the physician with the image detail comparable to conventional image acquisition while reducing dose to the patient.

Proceedings Article | 28 February 2009 Paper

Angiographic analysis of animal model aneurysms treated with novel polyurethane asymmetric vascular stent (P-AVS): feasibility study

Ciprian Ionita, Andreea Dohatcu, Andrey Sinelnikov, Jason Sherman, Christos Keleshis, Ann Paciorek, K. Hoffmann, D. Bednarek, S. Rudin

Proceedings Volume 7262, 72621H (2009) https://doi.org/10.1117/12.812628

KEYWORDS: Angiography, Neck, Scanning electron microscopy, Arteries, Polyurethane, In vivo imaging, Animal model studies, Electron microscopy, Hemodynamics, Domes

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Proceedings Article | 26 March 2008 Paper

3D-3D alignment using particle swarm optimization

Sebastian Schafer, Kenneth Hoffmann, Peter Noël, Christina Bloebaum

Proceedings Volume 6914, 691431 (2008) https://doi.org/10.1117/12.771685

KEYWORDS: Particle swarm optimization, Particles, Head, Teeth, Data acquisition, Alignment procedures, Data fusion, Optimization (mathematics), X-rays, Tomography

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Proceedings Article | 25 March 2008 Paper

LabVIEW graphical user interface for a new high sensitivity, high resolution micro-angio-fluoroscopic and ROI-CBCT system

C. Keleshis, C. Ionita, G. Yadava, V. Patel, D. Bednarek, K. Hoffmann, A. Verevkin, S. Rudin

Proceedings Volume 6913, 69135A (2008) https://doi.org/10.1117/12.769630

KEYWORDS: Cameras, Sensors, LabVIEW, Human-machine interfaces, Image processing, Digital filtering, Angiography, Fluoroscopy, X-rays, Image resolution

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Proceedings Article | 20 March 2008 Paper

Investigation of new flow modifying endovascular image-guided interventional (EIGI) techniques in patient-specific aneurysm phantoms (PSAPs) using optical imaging

J. Sherman, H. Rangwala, C. Ionita, A. Dohatcu, J. Lee, D. Bednarek, K. Hoffmann, S. Rudin

Proceedings Volume 6918, 69181V (2008) https://doi.org/10.1117/12.772583

KEYWORDS: Arteries, Polyurethane, Optical imaging, 3D modeling, Charge-coupled devices, Blood circulation, Neck, Silicon, CCD cameras, Image segmentation

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Proceedings Article | 20 March 2008 Paper

Endovascular image-guided treatment of in-vivo model aneurysms with asymmetric vascular stents (AVS): evaluation with time-density curve angiographic analysis and histology

A. Dohatcu, C. Ionita, A. Paciorek, D. Bednarek, K. Hoffmann, S. Rudin

Proceedings Volume 6916, 69160P (2008) https://doi.org/10.1117/12.769504

KEYWORDS: Angiography, In vivo imaging, Collagen, X-rays, Neck, Blood circulation, Patents, Animal model studies, Tissues, Blood

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Proceedings Article | 18 March 2008 Paper

Distortion, orientation, and translation corrections of tiled EMCCD detectors for the new solid state x-ray image intensifier (SSXII)

Hidab Hamwi, Joseph Lee, Kenneth Hoffmann, Stephen Rudin, Aleksandr Verevkin

Proceedings Volume 6913, 69133T (2008) https://doi.org/10.1117/12.769633

KEYWORDS: Distortion, Electron multiplying charge coupled devices, Sensors, Fiber optics, Image intensifiers, Image quality, Signal to noise ratio, X-ray imaging, X-rays, Solid state electronics

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Proceedings Article | 17 March 2008 Paper

Implementation of a high-sensitivity micro-angiographic fluoroscope (HS-MAF) for in-vivo endovascular image guided interventions (EIGI) and region-of-interest computed tomography (ROI-CT)

C. Ionita, C. Keleshis, V. Patel, G. Yadava, K. Hoffmann, D. Bednarek, A. Jain, S. Rudin

Proceedings Volume 6918, 69181I (2008) https://doi.org/10.1117/12.770297

KEYWORDS: Sensors, Angiography, Fluoroscopy, Arteries, X-rays, In vivo imaging, X-ray imaging, Data acquisition, Computed tomography, X-ray detectors

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Proceedings Article | 3 April 2007 Paper

Evaluation of the effect of partial asymmetric stent coverage on neurovascular aneurysm hemodynamics using computer fluid dynamics (CFD) calculations

Minsuok Kim, Hussain Rangwala, Ciprian Ionita, Kenneth Hoffmann, Dale Taulbee, Hui Meng, Stephen Rudin

Proceedings Volume 6509, 65092I (2007) https://doi.org/10.1117/12.708752

KEYWORDS: Hemodynamics, Visualization, Angiography, Arteries, 3D modeling, Fluid dynamics, Cerebral aneurysms, Computational fluid dynamics, CT reconstruction, Visual analytics

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Proceedings Article | 29 March 2007 Paper

Linear programming approach to optimize 3D data obtained from multiple view angiograms

Peter Noël, Jinhui Xu, Kenneth Hoffmann, Vikas Singh, Sebastian Schafer, Alan Walczak

Proceedings Volume 6511, 65112F (2007) https://doi.org/10.1117/12.709499

KEYWORDS: Angiography, Calibration, Computer programming, Imaging systems, 3D image processing, Cerebrovascular diseases, Visualization, Error analysis, Scientific programming, Data centers

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Proceedings Article | 22 March 2007 Paper

Planning image-guided endovascular interventions: guidewire simulation using shortest path algorithms

Sebastian Schafer, Vikas Singh, Kenneth Hoffmann, Peter Noël, Jinhui Xu

Proceedings Volume 6509, 65092C (2007) https://doi.org/10.1117/12.709519

KEYWORDS: Computer simulations, Arteries, Angiography, 3D modeling, Surgery, X-rays, Data modeling, Instrument modeling, Data acquisition, Signal attenuation

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Proceedings Article | 13 March 2006 Paper

Flow modification in canine intracranial aneurysm model by an asymmetric stent: studies using digital subtraction angiography (DSA) and image-based computational fluid dynamics (CFD) analyses

Yiemeng Hoi, Ciprian Ionita, Rekha Tranquebar, Kenneth Hoffmann, Scott Woodward, Dale Taulbee, Hui Meng, Stephen Rudin

Proceedings Volume 6143, 61430J (2006) https://doi.org/10.1117/12.650624

KEYWORDS: Neck, Angiography, In vivo imaging, Arteries, Computational fluid dynamics, Hemodynamics, Animal model studies, In vitro testing, CFD analysis, Particles

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Proceedings Article | 13 March 2006 Paper

Evaluation of an asymmetric stent patch design for a patient specific intracranial aneurysm using computational fluid dynamic (CFD) calculations in the computed tomography (CT) derived lumen

Minsuok Kim, Ciprian Ionita, Rekha Tranquebar, Kenneth Hoffmann, Dale Taulbee, Hui Meng, Stephen Rudin

Proceedings Volume 6143, 61432G (2006) https://doi.org/10.1117/12.651773

KEYWORDS: Angiography, Arteries, Hemodynamics, Neck, Computational fluid dynamics, Blood circulation, Visualization, Cerebral aneurysms, Computer aided design, Computed tomography

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Proceedings Article | 10 March 2006 Paper

A linear programming based algorithm for determining corresponding point tuples in multiple vascular images

Vikas Singh, Jinhui Xu, Kenneth Hoffmann, Peter Noël, Alan Walczak

Proceedings Volume 6144, 61442D (2006) https://doi.org/10.1117/12.651707

KEYWORDS: 3D image processing, Computer programming, Reconstruction algorithms, Imaging systems, 3D image reconstruction, Angiography, 3D modeling, Chemical elements, X-ray sources, Computer simulations

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Proceedings Article | 3 March 2006 Paper

New light-amplifier-based detector designs for high spatial resolution and high sensitivity CBCT mammography and fluoroscopy

Stephen Rudin, Andrew Kuhls, Girijesh Yadava, Gaurav Josan, Ye Wu, Ravishankar Chityala, Hussain Rangwala, N. Ciprian Ionita, Kenneth Hoffmann, Daniel Bednarek

Proceedings Volume 6142, 61421R (2006) https://doi.org/10.1117/12.649501

KEYWORDS: Sensors, Electron multiplying charge coupled devices, CCD image sensors, Fluoroscopy, Charge-coupled devices, Mammography, Quantum efficiency, CCD cameras, X-rays, Microchannel plates

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Proceedings Article | 2 March 2006 Paper

Experimental comparison of cone beam CT (CBCT) reconstruction and multiview reconstruction (MVR) for microangiography (MA) detector system

Vikas Patel, Andrew Kuhls, Peter Noël, Alan Walczak, Ciprian Ionita, Ravishankar Chityala, Rekha Tranquebar, Hussain Rangwala, Snehal Kasodekar, Kenneth Hoffmann, Daniel Bednarek, Stephen Rudin

Proceedings Volume 6142, 61422D (2006) https://doi.org/10.1117/12.653845

KEYWORDS: 3D modeling, Sensors, Image segmentation, X-rays, 3D image processing, X-ray imaging, Reconstruction algorithms, 3D imaging standards, Image resolution, X-ray detectors

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Proceedings Article | 2 March 2006 Paper

New microangiography system development providing improved small vessel imaging, increased contrast-to-noise ratios, and multiview 3D reconstructions

Andrew Kuhls, Vikas Patel, Ciprian Ionita, Peter Noël, Alan Walczak, Hussain Rangwala, Kenneth Hoffmann, Stephen Rudin

Proceedings Volume 6142, 61423M (2006) https://doi.org/10.1117/12.653654

KEYWORDS: Sensors, Imaging systems, 3D image processing, 3D modeling, Visualization, X-rays, 3D image reconstruction, Image intensifiers, Angiography, Image resolution

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Proceedings Article | 29 April 2005 Paper

A new algorithm for determining 3D biplane imaging geometry: theory and implementation

Vikas Singh, Jinhui Xu, Kenneth Hoffmann, Guang Xu, Zhenming Chen, Anant Gopal

Proceedings Volume 5747, (2005) https://doi.org/10.1117/12.594378

KEYWORDS: Imaging systems, Algorithms, 3D image processing, Stereoscopy, Medical imaging, Image processing, Visualization

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Proceedings Article | 29 April 2005 Paper

Artifact reduction in truncated CT using sinogram completion

Ravishankar Chityala, Kenneth Hoffmann, Stephen Rudin, Daniel Bednarek

Proceedings Volume 5747, (2005) https://doi.org/10.1117/12.595450

KEYWORDS: Head, Radon transform, Signal attenuation, Data analysis, Data acquisition, Sensors, Computed tomography, Data centers, Image processing, Image acquisition

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Proceedings Article | 20 April 2005 Paper

Region of interest (ROI) computed tomography (CT): comparison with full field of view (FFOV) and truncated CT for a human head phantom

R. Chityala, K. Hoffmann, S. Rudin, D. Bednarek

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.595430

KEYWORDS: Image filtering, Sensors, Head, Computed tomography, Signal attenuation, CT reconstruction, X-ray computed tomography, X-ray sources, Reconstruction algorithms, Data acquisition

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Proceedings Article | 20 April 2005 Paper

Generalized performance evaluation of x-ray image intensifier compared with a microangiographic system

Girijesh Yadava, Iacovos Kyprianou, Stephen Rudin, Daniel Bednarek, Kenneth Hoffmann

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.594593

KEYWORDS: Sensors, Modulation transfer functions, Image intensifiers, Imaging systems, Spatial frequencies, X-ray imaging, X-rays, Silver, Radiation effects, X-ray detectors

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Proceedings Article | 12 April 2005 Paper

Microangiographic image-guided localization of a new asymmetric stent for treatment of cerebral aneurysms

Ciprian Ionita, Stephen Rudin, Kenneth Hoffmann, Daniel Bednarek

Proceedings Volume 5744, (2005) https://doi.org/10.1117/12.594789

KEYWORDS: Sensors, Image intensifiers, X-rays, X-ray detectors, Head, Gold, Cerebral aneurysms, X-ray imaging, Prototyping, Angiography

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Proceedings Article | 12 April 2005 Paper

Configuration-space technique for calculating stent-fitness measures for the planning of neuro-endovascular interventions

Thenkurussi Kesavadas, Rajendra Agrawal, Kenneth Hoffmann

Proceedings Volume 5744, (2005) https://doi.org/10.1117/12.594544

KEYWORDS: Tolerancing, Algorithm development, Reconstruction algorithms, Clouds, Data acquisition, Surgery, Angiography, 3D acquisition, 3D vision, Visibility

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Proceedings Article | 6 May 2004 Paper

Region of interest (ROI) computed tomography

Ravishankar Chityala, Kenneth Hoffmann, Daniel Bednarek, Stephen Rudin

Proceedings Volume 5368, (2004) https://doi.org/10.1117/12.534568

KEYWORDS: Computed tomography, Sensors, Image filtering, Data acquisition, Spatial resolution, X-rays, X-ray computed tomography, Image quality, Medical research, 3D modeling

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Proceedings Article | 6 May 2004 Paper

Study of the generalized MTF and DQE for a new microangiographic system

Iacovos Kyprianou, Stephen Rudin, Daniel Bednarek, Kenneth Hoffmann

Proceedings Volume 5368, (2004) https://doi.org/10.1117/12.533512

KEYWORDS: Sensors, Modulation transfer functions, X-rays, X-ray detectors, Signal detection, Spatial frequencies, Head, Angiography, Scattering, Iodine

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Proceedings Article | 5 May 2004 Paper

A computer-graphic display for real-time operator feedback during interventional x-ray procedures

Kevin Chugh, Petru Dinu, Daniel Bednarek, Darold Wobschall, Stephen Rudin, Kenneth Hoffmann, Ron Peterson, Ming Zeng

Proceedings Volume 5367, (2004) https://doi.org/10.1117/12.537230

KEYWORDS: X-rays, Visualization, Skin, Signal processing, Fluoroscopy, Databases, Beam shaping, Analog electronics, Data modeling, Optical tracking

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Proceedings Article | 30 April 2004 Paper

Angiographic analysis of blood flow modification in cerebral aneurysm models with a new asymmetric stent

Zhou Wang, Ciprian Ionita, Stephen Rudin, Kenneth Hoffmann, Adam Paxton, Daniel Bednarek

Proceedings Volume 5369, (2004) https://doi.org/10.1117/12.535347

KEYWORDS: Blood circulation, Angiography, X-rays, Cerebral aneurysms, Blood, Radio optics, X-ray imaging, Cameras, Imaging systems, Neck

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Proceedings Article | 9 May 2002 Paper

Reconstruction of asymmetric vessel lumen from two views

Anant Gopal, Kenneth Hoffmann, Stephen Rudin, Daniel Bednarek

Proceedings Volume 4684, (2002) https://doi.org/10.1117/12.467165

KEYWORDS: Angiography, 3D modeling, X-rays, Image segmentation, 3D image processing, Reconstruction algorithms, Imaging systems, Data conversion, Sensors, Model-based design

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Proceedings Article | 9 May 2002 Paper

Determination of biplane geometry and centerline curvature in vascular imaging

Daryl Nazareth, Kenneth Hoffmann, Alan Walczak, Jacek Dmochowski, Lee Guterman, Stephen Rudin, Daniel Bednarek

Proceedings Volume 4684, (2002) https://doi.org/10.1117/12.467237

KEYWORDS: 3D image processing, Image segmentation, Imaging systems, Vascular imaging, Information visualization, Calibration, 3D image reconstruction, Visualization, Image analysis, Lithium

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Proceedings Article | 24 April 2002 Paper

Curvature-vector pair and its application in displaying CT colon data

Zhan Zhang, Kenneth Hoffmann, Alan Walczak

Proceedings Volume 4683, (2002) https://doi.org/10.1117/12.463585

KEYWORDS: Colon, Inspection, Virtual colonoscopy, Fiber optics, Visualization, Colorectal cancer, Computed tomography, Image enhancement, Cancer, Sigmoidoscopy

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Proceedings Article | 28 June 2001 Paper

Direct-conversion flat-panel detector for region-of-interest angiography

Arundhuti Ganguly, Stephen Rudin, Daniel Bednarek, Kenneth Hoffmann, Chang-Ying Yang, Zhou Wang

Proceedings Volume 4320, (2001) https://doi.org/10.1117/12.430949

KEYWORDS: CCD cameras, Sensors, Modulation transfer functions, Angiography, Optical transfer functions, X-rays, Imaging systems, Image quality, Charge-coupled devices, CCD image sensors

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Proceedings Article | 25 April 2000 Paper

Region of interest (ROI) microangiography: imager development

Stephen Rudin, Daniel Bednarek, Chang-Ying Yang, Arundhuti Chattopadhyay, Anant Gopal, Ye Wu, Zhou Wang, Daryl Nazareth, Kenneth Hoffmann

Proceedings Volume 3977, (2000) https://doi.org/10.1117/12.384529

KEYWORDS: Sensors, Cameras, X-rays, Imaging systems, Modulation transfer functions, Prototyping, CCD image sensors, Angiography, Charge-coupled devices, Fiber optics

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Proceedings Article | 18 April 2000 Paper

Estimation of catheter orientations from single-plane x-ray images

Jacqueline Esthappan, Kenneth Hoffmann

Proceedings Volume 3976, (2000) https://doi.org/10.1117/12.383047

KEYWORDS: 3D modeling, Data modeling, 3D image processing, Imaging systems, Signal to noise ratio, X-ray imaging, X-rays, Error analysis, In vivo imaging, Systems modeling

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Proceedings Article | 21 May 1999 Paper

Automatic detection of pulmonary nodules in low-dose screening thoracic CT examinations

Martin Fiebich, Christian Wietholt, Bernhard Renger, Samuel Armato, Kenneth Hoffmann, Dag Wormanns, Stefan Diederich

Proceedings Volume 3661, (1999) https://doi.org/10.1117/12.348543

KEYWORDS: Lung, Chest, Computed tomography, Tissues, Lung cancer, Feature extraction, Image segmentation, Collimation, Visualization, Image processing

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Proceedings Article | 20 May 1999 Paper

Determination of 3D vessel motion from biplane cardiac sequences

Kenneth Hoffmann, Li Lan, Julio Esclarin, Jacqueline Esthappan, Anindya Sen, Kok-Gee Chua

Proceedings Volume 3660, (1999) https://doi.org/10.1117/12.349603

KEYWORDS: 3D image processing, Heart, Reliability, Lead, Lanthanum, Automatic tracking, Digital imaging, Medical imaging, 3D acquisition, Angiography

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Proceedings Article | 20 May 1999 Paper

Surface coverage in CT colography studies

Yaseen Samara, Abraham Dachman, Kenneth Hoffmann

Proceedings Volume 3660, (1999) https://doi.org/10.1117/12.349580

KEYWORDS: Colon, Colorectal cancer, Visualization, Natural surfaces, Cancer, Computed tomography, Image segmentation, Fiber optics, Rectum, Optical inspection

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Proceedings Article | 24 June 1998 Paper

Automated centerline tracking of the human colon

Yaseen Samara, Martin Fiebich, Abraham Dachman, Kunio Doi, Kenneth Hoffmann

Proceedings Volume 3338, (1998) https://doi.org/10.1117/12.310953

KEYWORDS: Colon, Colorectal cancer, Rectum, Cancer, Computed tomography, Virtual colonoscopy, Fiber optics, Inspection, Intestine, Lung cancer

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Proceedings Article | 24 June 1998 Paper

Fast semiautomatic techniques for segmentation of cranial vessels in CT angiographic studies

Martin Fiebich, Bernhard Renger, Vivek Sehgal, Christopher Straus, Kenneth Hoffmann

Proceedings Volume 3338, (1998) https://doi.org/10.1117/12.310829

KEYWORDS: Bone, Image segmentation, 3D modeling, Angiography, 3D image processing, Computed tomography, Visualization, Pathology, Skull, Image visualization

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Proceedings Article | 24 June 1998 Paper

Determination and evaluation of 3D biplane imaging geometries without a calibration object

Anindya Sen, Jacqueline Esthappan, Li Lan, Kok-Gee Chua, Kunio Doi, Kenneth Hoffmann

Proceedings Volume 3338, (1998) https://doi.org/10.1117/12.310870

KEYWORDS: 3D image processing, Calibration, Reliability, Copper, Stereoscopy, Angiography, Automatic tracking, 3D image reconstruction, 3D acquisition, 3D metrology

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Proceedings Article | 22 May 1997 Paper

Radiology information system control of a DICOM-based PACS

Fred Behlen, Steven Montner, Kenneth Hoffmann, Heber MacMahon, James Weldy, Richard Sayre

Proceedings Volume 3035, (1997) https://doi.org/10.1117/12.274567

KEYWORDS: Picture Archiving and Communication System, Radiology, Data storage, Control systems, Scanners, Data archive systems, Databases, Computer programming, Magnetism, Computer programming languages

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Proceedings Article | 22 May 1997 Paper

Multiresolution storage in a PACS archive

Fred Behlen, Kenneth Hoffmann, Heber MacMahon, Troy Folkner

Proceedings Volume 3035, (1997) https://doi.org/10.1117/12.274601

KEYWORDS: Image resolution, Picture Archiving and Communication System, Magnetism, Image retrieval, Radiography, Data archive systems, Image compression, Spatial resolution, Image processing, Internet

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Proceedings Article | 25 April 1997 Paper

Computer-assisted diagnosis in CT angiography of abdominal aortic aneurysms

Martin Fiebich, Myrosia Tomiak, Roger Engelmann, James McGill, Kenneth Hoffmann

Proceedings Volume 3034, (1997) https://doi.org/10.1117/12.274087

KEYWORDS: Image segmentation, Bone, Digital filtering, Angiography, 3D vision, 3D modeling, Image filtering, Visualization, Computed tomography, Arteries

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The purpose of this study was to develop methods for automatic 3D-segmentation and automatic quantification of vascular structures in CT angiographic studies, e.g., abdominal aortic aneurysms. Methods for segmentation were developed based on thresholding, maximum gradient, and second derivative techniques. All parameters for the segmentation are generated automatically, i.e. no user interaction is necessary for this process. Median filtering of all images is initially performed to reduce the image noise. The algorithm then automatically identifies the starting point inside the aorta for the volume growing. The segmentation of the vascular tree is achieved in two steps. First, only the aorta and small parts of branch vessels are segmented by using strong restrictions in the parameters for threshold and gradient. A description of the aorta is generated by fitting the detected outer border of the aorta with an ellipse. This description includes centerline, direction, contour, eccentricity, and area. In the second step, segmentation parameters are changed automatically for segmentation of branch vessels. A shaded surface display of the segmented structures is then generated. The segmentation of the aorta appears accurate, is fast, and the 3D display can be manipulated in real time. The quantitative description of the aorta is reliable giving reproducible information. Total CPU time for the segmentation and description is less than five minutes on a standard workstation. Time-consuming manual segmentation and parameterization of vascular structures are obviated, with 3D visualization and quantitative results available in minutes instead of hours. This technique for segmentation and description of the aorta and renal arteries shows the feasibility of computer assisted diagnosis in CT angiographic studies without user interaction. Besides the description, a rapid 3D view of the vessels is generated, often needed by the physician and normally only achievable by time consuming manual segmentation.

Proceedings Article | 25 April 1997 Paper

Analysis of 3D motion of in-vivo pacemaker leads

Kenneth Hoffmann, Benjamin Williams, Jacqueline Esthappan, Shiuh-Yung Chen, Martin Fiebich, John Carroll, Hajime Harauchi, Vince Doerr, G. Neal Kay, Allen Eberhardt, Mary Overland

Proceedings Volume 3034, (1997) https://doi.org/10.1117/12.274145

KEYWORDS: Lead, In vivo imaging, 3D acquisition, 3D image processing, Imaging systems, Motion analysis, Calibration, Electrodes, Failure analysis, Image acquisition

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In vivo analyses of pacemaker lead motion during the cardiac cycle have become important due to incidences of failure of some of the components. For the calculation and evaluation of in vivo stresses in pacemaker leads, the 3D motion of the lead must be determined. To accomplish this, we have developed a technique for calculation of the overall and relative 3D position, and thereby the 3D motion, of in vivo pacemaker leads through the cardiac cycle.Biplane image sequences of patients with pacemakers were acquired for at least two cardiac cycles. After the patient acquisitions, biplane images of a calibration phantom were obtained. The biplane imaging geometries were calculated from the images of the calibration phantom. Points on the electrodes and the lead centerlines were indicated manually in all acquired images. The indicated points along the leads were then fit using a cubic spline. In each projection, the cumulative arclength along the centerlines in two temporally adjacent images was used to identify corresponding points along the centerlines. To overcome the non-synchronicity of the biplane image acquisition, temporal interpolation was performed using these corresponding points based on a linear scheme. For each time point, corresponding points along the lead centerlines in the pairs of biplane images were identified using epipolar lines. The 3D lead centerlines were calculated from the calculated imaging geometries and the corresponding image points along the lead centerlines. From these data, 3D lead motion and the variations of the lead position with time were calculated and evaluated throughout the cardiac cycle. The reproducibility of the indicated lead centerlines was approximately 0.3 mm. The precision of the calculated rotation matrix and translation vector defining image geometry were approximately 2 mm. 3D positions were reproducible to within 2 mm. Relative positional errors were less than 0.3 mm. Lead motion correlated strongly with phases of the cardiac cycle. Our results indicate that complex motions of in vivo pacemaker leads can be precisely determined. Thus, we believe that this technique will provide precise 3D motion and shapes on which to base subsequent stress analysis of pacemaker lead components.

Proceedings Article | 1 May 1996 Paper

Long-term strategies for PACS archive design

Fred Behlen, Kenneth Hoffmann, Heber MacMahon

Proceedings Volume 2711, (1996) https://doi.org/10.1117/12.239233

KEYWORDS: Picture Archiving and Communication System, Magnetism, Data archive systems, Data storage, Radiology, Image storage, Chest imaging, Databases, Optical discs, Computing systems

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Proceedings Article | 16 April 1996 Paper

Image processing approaches for analysis of clinical duplex ultrasonography

Kenneth Hoffmann, Claire Pellot-Barakat, Shiuh-Yung Chen, Charles Pelizzari, Fred Winsberg, David Casalino

Proceedings Volume 2710, (1996) https://doi.org/10.1117/12.237916

KEYWORDS: Image segmentation, Ultrasonography, 3D image processing, Heart, 3D acquisition, Arteries, Transducers, 3D modeling, Image processing, Visualization

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Proceedings Article | 16 April 1996 Paper

Three-dimensional reconstruction of coronary arterial tree based on biplane angiograms

Shiuh-Yung Chen, Kenneth Hoffmann, John Carroll

Proceedings Volume 2710, (1996) https://doi.org/10.1117/12.237914

KEYWORDS: 3D image processing, Imaging systems, Angiography, Arteries, 3D modeling, Image segmentation, 3D metrology, Error analysis, Calibration, Heart

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Proceedings Article | 16 April 1996 Paper

Pincushion correction techniques and their effects on calculated 3D positions and imaging geometries

Kenneth Hoffmann, Yang Chen, Jacqueline Esthappan, Shiuh-Yung Chen, John Carroll

Proceedings Volume 2710, (1996) https://doi.org/10.1117/12.237948

KEYWORDS: 3D image processing, Imaging systems, Calibration, 3D image enhancement, Lead, Stereoscopy, Image intensifiers, Image enhancement, Distance measurement, Quantitative analysis

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Proceedings Article | 11 April 1996 Paper

Simple technique for calibrating imaging geometries

Kenneth Hoffmann, Jacqueline Esthappan, Shidong Li, Charles Pelizzari

Proceedings Volume 2708, (1996) https://doi.org/10.1117/12.237799

KEYWORDS: Imaging systems, Calibration, 3D image processing, Data modeling, Lead, 3D modeling, Systems modeling, 3D acquisition, Computer simulations, X-rays

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Proceedings Article | 12 May 1995 Paper

Image fusion for visualization of hepatic vasculature and tumors

Jin-Shin Chou, Shiuh-Yung Chen, Gary Sudakoff, Kenneth Hoffmann, Chin-Tu Chen, Abraham Dachman

Proceedings Volume 2434, (1995) https://doi.org/10.1117/12.208687

KEYWORDS: Liver, Visualization, 3D displays, Tumors, 3D image processing, Image fusion, Image visualization, Computed tomography, Image segmentation, Veins

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Proceedings Article | 14 September 1993 Paper

Segmentation and display of hepatic vessels and metastases

Kenneth Hoffmann, Shiuh-Yung Chen, Martti Kormano, Richard Coulden

Proceedings Volume 1898, (1993) https://doi.org/10.1117/12.154511

KEYWORDS: Liver, Image segmentation, Visualization, Image processing, Computed tomography, 3D displays, Magnetic resonance imaging, 3D image processing, Tumors, Image analysis

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Proceedings Article | 29 July 1993 Paper

Three-dimensional ventricle reconstruction from serial cross sections

Shiuh-Yung Chen, John Carroll, Chin-Tu Chen, Kenneth Hoffmann, Richard Coulden

Proceedings Volume 1905, (1993) https://doi.org/10.1117/12.148623

KEYWORDS: 3D modeling, Reconstruction algorithms, Heart, 3D image processing, 3D image reconstruction, Ultrafast imaging, Image segmentation, Computed tomography, X-ray computed tomography, Data acquisition

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Proceedings Article | 1 August 1992 Paper

Modeling human heart based on cardiac tomography

Shiuh-Yung Chen, Kenneth Hoffmann, Chin-Tu Chen, John Carroll

Proceedings Volume 1778, (1992) https://doi.org/10.1117/12.130952

KEYWORDS: Heart, Tomography

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Proceedings Article | 1 July 1992 Paper

User interface optimization in a radiography display console

Fred Behlen, Douglas Sluis, Heber MacMahon, Maryellen Giger, Kenneth Hoffmann, Kunio Doi

Proceedings Volume 1654, (1992) https://doi.org/10.1117/12.60297

KEYWORDS: Human-machine interfaces, Radiography, Image display, Image quality, Displays, Zoom lenses

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Proceedings Article | 1 March 1991 Paper

Automated extraction of vascular information from angiographic images using a vessel-tracking algorithm

Noam Alperin, Kenneth Hoffmann, Kunio Doi

Proceedings Volume 1396, (1991) https://doi.org/10.1117/12.47735

KEYWORDS: Image segmentation, Angiography, Optical tracking, Image analysis, Blood circulation, Vascular diseases, Optical engineering, Algorithm development, Detection and tracking algorithms, Radiology

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Proceedings Article | 1 July 1990 Paper

New angiographic technique for measurement of instantaneous blood flow rates using distance-density curves

Kenneth Hoffmann, Kunio Doi

Proceedings Volume 1233, (1990) https://doi.org/10.1117/12.18909

KEYWORDS: Angiography, Blood circulation, Image acquisition, Electromagnetism, Digital imaging, Vascular diseases, Image processing, Image analysis, Distance measurement, Error analysis

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Showing 5 of 61 publications

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