Dr. Erik L. Ritman Profile

Dr. Erik L. Ritman

Professor at Mayo Clinic

SPIE Involvement:

Author

Publications (60)

SPIE Journal Paper | 6 February 2023

Measurement of enhanced vasa vasorum density in a porcine carotid model using photon counting detector CT

Jeffrey F. Marsh, Andrew J. Vercnocke, Kishore Rajendran, Shengzhen Tao, Jill L. Anderson, Erik L. Ritman, Shuai Leng, Cynthia H. McCollough

JMI, Vol. 10, Issue 01, 016001, (February 2023) https://doi.org/10.1117/12.10.1117/1.JMI.10.1.016001

KEYWORDS: Arteries, Iodine, Animals, Computed tomography, X-ray computed tomography, Image enhancement, Tissues, Attenuation, Animal model studies, Voxels

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SPIE Journal Paper | 1 October 2020

Overcoming calcium blooming and improving the quantification accuracy of percent area luminal stenosis by material decomposition of multi-energy computed tomography datasets

Zhoubo Li, Shuai Leng, Ahmed Halaweish, Zhicong Yu, Lifeng Yu, Erik Ritman, Cynthia McCollough

JMI, Vol. 7, Issue 05, 053501, (October 2020) https://doi.org/10.1117/12.10.1117/1.JMI.7.5.053501

KEYWORDS: Iodine, Calcium, Computed tomography, Image segmentation, Error analysis, Spatial resolution, Sensors, Signal attenuation, Computer simulations, Arteries

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Purpose: Conventional stenosis quantification from single-energy computed tomography (SECT) images relies on segmentation of lumen boundaries, which suffers from partial volume averaging and calcium blooming effects. We present and evaluate a method for quantifying percent area stenosis using multienergy CT (MECT) images. Approach: We utilize material decomposition of MECT images to measure stenosis based on the ratio of iodine mass between vessel locations with and without a stenosis, thereby eliminating the requirement for segmentation of iodinated lumen. The method was first assessed using simulated MECT images created with different spatial resolutions. To experimentally assess this method, four phantoms with different stenosis severity (30% to 51%), vessel diameters (5.5 to 14 mm), and calcification densities (700 to 1100 mgHA / cc) were fabricated. Conventional SECT images were acquired using a commercial CT system and were analyzed with commercial software. MECT images were acquired using a commercial dual-energy CT (DECT) system and also from a research photon-counting detector CT (PCD-CT) system. Three-material-decomposition was performed on MECT data, and iodine density maps were used to quantify stenosis. Clinical radiation doses were used for all data acquisitions. Results: Computer simulation verified that this method reduced partial volume and blooming effects, resulting in consistent stenosis measurements. Phantom experiments showed accurate and reproducible stenosis measurements from MECT images. For DECT and two-threshold PCD-CT images, the estimation errors were 4.0% to 7.0%, 2.0% to 9.0%, 10.0% to 18.0%, and −1.0 % to −5.0 % (ground truth: 51%, 51%, 51%, and 30%). For four-threshold PCD-CT images, the errors were 1.0% to 3.0%, 4.0% to 6.0%, −1.0 % to 9.0%, and 0.0% to 6.0%. Errors using SECT were much larger, ranging from 4.4% to 46%, and were especially worse in the presence of dense calcifications. Conclusions: The proposed approach was shown to be insensitive to acquisition parameters, demonstrating the potential to improve the accuracy and precision of stenosis measurements in clinical practice.

Proceedings Article | 16 March 2020 Paper

A blooming correction technique for improved vasa vasorum detection using an ultra-high-resolution photon-counting detector CT

Jeffrey Marsh, Kishore Rajendran, Shengzhen Tao, Andrew Vercnocke, Jill Anderson, Shuai Leng, Erik Ritman, Cynthia McCollough

Proceedings Volume 11312, 113124R (2020) https://doi.org/10.1117/12.2549348

KEYWORDS: Computed tomography, Arteries, Iodine, Sensors, Data modeling, Animal model studies, X-ray computed tomography, Contamination, Signal attenuation, Image segmentation

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SPIE Journal Paper | 4 December 2018

Evaluation of a photon counting Medipix3RX cadmium zinc telluride spectral x-ray detector

Jeffrey Marsh, Steven Jorgensen, David Rundle, Andrew J. Vercnocke, Shuai Leng, Philip Butler, Cynthia McCollough, Erik Ritman

JMI, Vol. 5, Issue 04, 043503, (December 2018) https://doi.org/10.1117/12.10.1117/1.JMI.5.4.043503

KEYWORDS: Sensors, X-ray detectors, X-rays, Photon counting, Mars, Cadmium, Zinc, X-ray imaging, X-ray sources, Scanners

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SPIE Journal Paper | 8 December 2017

Measuring arterial wall perfusion using photon-counting computed tomography (CT): improving CT number accuracy of artery wall using image deconvolution

Kishore Rajendran, Shuai Leng, Steven Jorgensen, Jill Anderson, Ahmed Halaweish, Dilbar Abdurakhimova, Erik Ritman, Cynthia McCollough

JMI, Vol. 4, Issue 04, 044006, (December 2017) https://doi.org/10.1117/12.10.1117/1.JMI.4.4.044006

KEYWORDS: Computed tomography, Arteries, Image deconvolution, Deconvolution, Optical computing, Point spread functions, 3D modeling, Imaging systems, Scanners, Animal model studies

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Proceedings Article | 9 March 2017 Paper

Detection of increased vasa vasorum in artery walls: improving CT number accuracy using image deconvolution

Kishore Rajendran, Shuai Leng, Steven Jorgensen, Dilbar Abdurakhimova, Erik Ritman, Cynthia McCollough

Proceedings Volume 10132, 101323O (2017) https://doi.org/10.1117/12.2255676

KEYWORDS: Computed tomography, Arteries, Image deconvolution, Point spread functions, Photon counting, X-ray computed tomography, Medicine, Image enhancement

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SPIE Journal Paper | 22 December 2016

Dose-efficient ultrahigh-resolution scan mode using a photon counting detector computed tomography system

Shuai Leng, Zhicong Yu, Ahmed Halaweish, Steffen Kappler, Katharina Hahn, Andre Henning, Zhoubo Li, John Lane, David Levin, Steven Jorgensen, Erik Ritman, Cynthia McCollough

JMI, Vol. 3, Issue 04, 043504, (December 2016) https://doi.org/10.1117/12.10.1117/1.JMI.3.4.043504

KEYWORDS: Sensors, Lung, Spatial resolution, Computed tomography, Photon counting, Scanners, Bone, Modulation transfer functions, Head, Image quality

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Proceedings Article | 4 October 2016 Paper

Arterial wall perfusion measured with photon counting spectral x-ray CT

Steven Jorgensen, Mark Korinek, Andrew Vercnocke, Jill Anderson, Ahmed Halaweish, Shuai Leng, Cynthia McCollough, Erik Ritman

Proceedings Volume 9967, 99670B (2016) https://doi.org/10.1117/12.2238817

KEYWORDS: X-rays, Arteries, X-ray computed tomography, Veins, Computed tomography, Photon counting, Blood, Sensors, Neck, Spatial resolution

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Proceedings Article | 3 October 2016 Paper

Evaluation of a photon counting Medipix3RX CZT spectral x-ray detector

Steven Jorgensen, Andrew Vercnocke, David Rundle, Philip Butler, Cynthia McCollough, Erik Ritman

Proceedings Volume 9969, 99690J (2016) https://doi.org/10.1117/12.2236501

KEYWORDS: X-rays, Sensors, X-ray detectors, X-ray imaging, Photon counting, X-ray sources, Image resolution, Cameras, Tin, Manufacturing

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Proceedings Article | 4 April 2016 Paper

Low-dose performance of a whole-body research photon-counting CT scanner

Zhicong Yu, Shuai Leng, Steffen Kappler, Katharina Hahn, Zhoubo Li, Ahmed Halaweish, Andre Henning, Erik Ritman, Cynthia McCollough

Proceedings Volume 9783, 97835Q (2016) https://doi.org/10.1117/12.2217240

KEYWORDS: Computed tomography, Scanners, Photon counting, Image quality, Data acquisition, Modulation transfer functions, X-ray computed tomography, Medicine, Spatial resolution

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Proceedings Article | 25 March 2016 Paper

A high-resolution imaging technique using a whole-body, research photon counting detector CT system

S. Leng, Z. Yu, A. Halaweish, S. Kappler, K. Hahn, A. Henning, Z. Li, J. Lane, D. Levin, S. Jorgensen, E. Ritman, C. McCollough

Proceedings Volume 9783, 97831I (2016) https://doi.org/10.1117/12.2217180

KEYWORDS: Spatial resolution, Modulation transfer functions, Lung, Bone, Photon counting, Sensors, Imaging systems, Computed tomography, Image quality, Scanners, X-ray computed tomography, Heart

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Proceedings Article | 18 March 2015 Paper

Initial results from a prototype whole-body photon-counting computed tomography system

Z. Yu, S. Leng, S. Jorgensen, Z. Li, R. Gutjahr, B. Chen, X. Duan, A. Halaweish, L. Yu, E. Ritman, C. McCollough

Proceedings Volume 9412, 94120W (2015) https://doi.org/10.1117/12.2082739

KEYWORDS: Prototyping, Iodine, Head, Modulation transfer functions, Spatial resolution, X-ray computed tomography, Sensors, Image quality, X-rays, Computed tomography

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Proceedings Article | 12 September 2014 Paper

CT image-based quantification of sub-pixel diameter microparticle accumulations in tissues using á priori biological information

Andrew Vercnocke, Jill Anderson, Steven Jorgensen, Erik Ritman

Proceedings Volume 9212, 92121C (2014) https://doi.org/10.1117/12.2062314

KEYWORDS: Particles, Sensors, Signal attenuation, X-rays, X-ray detectors, Tissues, Opacity, X-ray imaging, X-ray computed tomography, Nanoparticles

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Proceedings Article | 15 September 2011 Open Access

Biomedical spectral x-ray imaging: promises and challenges

Steven Jorgensen, Diane Eaker, Erik Ritman

Proceedings Volume 8143, 814302 (2011) https://doi.org/10.1117/12.904615

KEYWORDS: X-rays, X-ray imaging, X-ray computed tomography, Sensors, Photodetectors, Biomedical optics, X-ray sources, Imaging arrays, Photon counting, X-ray detectors

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Proceedings Article | 11 February 2011 Paper

Role of microcomputed tomography in microvascular imaging

Erik Ritman

Proceedings Volume 7898, 78980I (2011) https://doi.org/10.1117/12.881396

KEYWORDS: X-rays, Tissues, X-ray imaging, 3D image processing, Blood vessels, Scanners, Blood, Signal attenuation, Arteries, Tomography

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Proceedings Article | 20 September 2010 Paper

Tomographic imaging of coherent x-ray scatter momentum transfer distribution using spectral x-ray detection and polycapillary optic

Diane Eaker, Steven Jorgensen, Anthony P. Butler, Erik Ritman

Proceedings Volume 7804, 78041O (2010) https://doi.org/10.1117/12.861508

KEYWORDS: X-rays, X-ray imaging, Signal attenuation, Sensors, Coherence imaging, Fluctuations and noise, X-ray detectors, X-ray optics, X-ray sources, Tomography

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Proceedings Article | 23 March 2010 Paper

A preliminary study of few-view image reconstruction of sparse objects in cone-beam micro-CT

Xiao Han, Junguo Bian, Diane Eaker, Emil Sidky, Erik Ritman, Xiaochuan Pan

Proceedings Volume 7622, 76222P (2010) https://doi.org/10.1117/12.845320

KEYWORDS: Image restoration, Reconstruction algorithms, Medical imaging, Imaging systems, Image processing, Physics, Current controlled current source, Visual analytics, Visualization, Quantitative analysis

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Proceedings Article | 22 March 2010 Paper

A super resolution technique for clinical multislice CT

Xin Liu, Lifeng Yu, Armando Manduca, Erik Ritman, Cynthia McCollough

Proceedings Volume 7622, 76221Q (2010) https://doi.org/10.1117/12.844831

KEYWORDS: Image resolution, Super resolution, Spatial resolution, Sensors, Image quality, Data processing, X-rays, Computed tomography, X-ray computed tomography, Detection and tracking algorithms

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Proceedings Article | 9 March 2010 Paper

Erode/dilate analysis of micro-CT images of porcine myocardial microvasculature

Timothy Kline, Yue Dong, Mair Zamir, Erik Ritman

Proceedings Volume 7626, 762620 (2010) https://doi.org/10.1117/12.845611

KEYWORDS: Biopsy, Image segmentation, Image analysis, Biological research, 3D image processing, Binary data, Wave propagation, Arteries, Medicine, Visualization

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Proceedings Article | 28 February 2009 Paper

Micro-CT analysis of sea sponge pore architecture as a model of a cell-populated synthetic tissue scaffold

Amber Plath, Timothy Kline, Diane Eaker, Patricia Beighley, Andrew Vercnocke, Erik Ritman

Proceedings Volume 7262, 72622K (2009) https://doi.org/10.1117/12.813581

KEYWORDS: Throat, Tissues, Image segmentation, Image analysis, Natural surfaces, X-ray imaging, X-rays, 3D image processing, Diffusion, Scanners

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Sponges consist of a tissue skeleton that provides structure for its elaborate pore system of canals and chambers. Sponges have been noted for their remarkable ability to support cellular life within these pores. For that reason, their structure is of great interest to us since our goal is to create a scaffold that supports cell vitality beyond diffusion depth from the scaffold surface. In the sponge this is achieved by convective transport of nutrients through the pore system. Hence, understanding of the architecture of sea sponges has the potential to aid in the production of better design of porous, cell-populated, synthetic tissue scaffolds. Pore geometry affects depth and distribution of the solute transport needed to sustain the cells lining the pores. To explore this aspect we need accurate 3D measurements of pore architecture and interconnectivity. Three-dimensional micro-CT imaging can be used to characterize the desired microarchitecture labyrinthine pore structure of a sea sponge. The sea sponge was collected, dried, and then rotated in small angular measurements inside the scanner as an x-ray image was obtained at each angle of view. Reconstructed cross-sectional images of the sponge consisted of up to 10⁷ cubic voxels, 20μm on a side. After reconstruction, Analyze 8.1 was used to display and generate measurements of the sponge's pores. The pores were subjected to a sequence of morphological erosion and dilation operations, each of which either removed or added one layer of voxels from the outer surface of the segmented pore. Hence, each erosion removed 40μm from the diameter of a pore. Progressive erosions were used to calculate pore volume and to disconnect pores from adjacent pores, thereby identifying connecting throats(s) as well as their diameter. Along with diameter, individual pore volume and surface area were also computed. Results show that the throats were predominately 264±129μm in diameter. Preliminary data show complex pore structures can be analyzed with morphological erosion and dilation image analysis techniques to provide significant quantitative data. Such data has provided information about throat identification and diameter, as well as pore volume and surface area. Ground work has also been laid for computing flow path of least resistance through the pore labyrinth from any point in the labyrinth.

Proceedings Article | 28 February 2009 Paper

Micro-CT analysis of myocardial blood supply in young and adult rats

Heather Schaefer, Patricia Beighley, Diane Eaker, Andrew Vercnocke, Erik Ritman

Proceedings Volume 7262, 726225 (2009) https://doi.org/10.1117/12.812125

KEYWORDS: Heart, Blood, Image segmentation, Image analysis, Arteries, 3D image processing, Binary data, 3D scanning, Fractal analysis, X-ray sources

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Proceedings Article | 18 September 2008 Paper

Coherent x-ray scattering for discriminating bio-compatible materials in tissue scaffolds

Congwu Cui, Steven Jorgensen, Diane Eaker, Erik Ritman

Proceedings Volume 7078, 70781S (2008) https://doi.org/10.1117/12.793321

KEYWORDS: X-rays, Tissues, X-ray sources, Polymers, Molybdenum, X-ray imaging, Signal attenuation, Scattering, Epoxies, Scatter measurement

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Proceedings Article | 15 September 2008 Paper

Whole-body imaging of whole-organ, subresolution, basic functional unit (BFU) perfusion characteristics

Yue Dong, Erik Ritman

Proceedings Volume 7078, 707806 (2008) https://doi.org/10.1117/12.793169

KEYWORDS: Blood, Computed tomography, Scanners, Statistical analysis, Data modeling, Heart, Image analysis, Arteries, Fractal analysis, Whole body imaging

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Proceedings Article | 3 April 2008 Paper

High resolution x-ray imaging of dynamic solute transport in cyclically deformed porous tissue scaffolds

Jorn Op Den Buijs, Kee-Won Lee, Steven Jorgensen, Shanfeng Wang, Michael Yaszemski, Erik Ritman

Proceedings Volume 6916, 69161A (2008) https://doi.org/10.1117/12.772057

KEYWORDS: X-rays, Image compression, X-ray imaging, Tissues, Polymers, Signal attenuation, 3D printing, Image resolution, Fabrication, Computer aided design

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Proceedings Article | 12 March 2008 Paper

Intramyocardial capillary blood volume estimated by whole-body CT: validation by micro-CT

Yue Dong, Patricia Beighley, Diane Eaker, Mair Zamir, Erik Ritman

Proceedings Volume 6916, 691624 (2008) https://doi.org/10.1117/12.772713

KEYWORDS: Blood, Computed tomography, Capillaries, Arteries, Heart, Image segmentation, Image resolution, Veins, Electron beams, Scanners

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Proceedings Article | 31 August 2006 Paper

Micro-CT as a guide for clinical CT development

Erik Ritman, Diane Eaker, Steven Jorgensen

Proceedings Volume 6318, 631801 (2006) https://doi.org/10.1117/12.679490

KEYWORDS: X-rays, X-ray computed tomography, Heart, Tissues, Computed tomography, Arteries, Blood, 3D image processing, X-ray imaging, Scanners

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Proceedings Article | 13 March 2006 Paper

Reproducibility of 3D micro-CT gray-scale and structural dimension data in longitudinal studies

Steven Jorgensen, Diane Eaker, Andrew Vercnocke, Erik Ritman

Proceedings Volume 6143, 61433H (2006) https://doi.org/10.1117/12.654436

KEYWORDS: Bone, X-rays, X-ray imaging, Computed tomography, Biopsy, 3D image processing, Scanners, Charge-coupled devices, Modulation transfer functions, Signal attenuation

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Proceedings Article | 16 November 2005 Paper

System for 3D visualization and data mining of large vascular trees

Kun-Chang Yu, Erik Ritman, William Higgins

Proceedings Volume 6016, 60160B (2005) https://doi.org/10.1117/12.629899

KEYWORDS: 3D image processing, Visualization, Image segmentation, Data mining, Visual analytics, Surgery, 3D visualizations, Computing systems, Image processing, 3D scanning

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Proceedings Article | 20 April 2005 Paper

Micro gamma camera optics with high sensitivity and resolution

C. MacDonald, Noor Mail, W. Gibson, S. Jorgenson, E. Ritman

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.597193

KEYWORDS: Collimators, Sensors, Image resolution, Radio optics, Capillaries, Cameras, X-ray optics, Glasses, Signal to noise ratio, X-rays

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Proceedings Article | 14 April 2005 Paper

Characterization of sub-resolution microcirculatory status using whole-body CT imaging

Yue Dong, Nasser Malyar, Patricia Beighley, Erik Ritman

Proceedings Volume 5746, (2005) https://doi.org/10.1117/12.595986

KEYWORDS: Scanners, Blood, Computed tomography, Arteries, Fractal analysis, Statistical analysis, Image analysis, Heart, 3D image processing, Francium

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Myocardial microcirculation disturbances often precede angiographically visible of narrowing large epicardial coronary arteries and associated symptoms. Clinical tomographic imaging cannot resolve the microcirculation, hence an indirect method of quantitating microvascular disturbances in those images must be developed. We propose that such an indirect method can be based on the characterization of the spatial heterogeneity of myocardial intravascular blood volume. We evaluated the relationship of multi-resolution, nested multi Region-of-Interest (ROI) analysis of EBCT images to the actual intravascular volume of microvascular branches as measured directly with micro-CT images in the same myocardial regions. We selectively altered the intravascular volume of vessels by injecting 30, 100, 200 or 300μm diameter microspheres into anesthetized pigs’ LAD coronary arteries prior to EBCT scanning during contrast injection. The heart was then harvested and the LAD coronary artery was infused with Microfil polymer. An approximately 2cm³ transmural “biopsy” of the same ROI within the myocardium analyzed in the EBCT images was scanned by micro-CT resulting in a 3D image of 20μm cubic voxels. Myocardial opacification was measured in both the EBCT and micro-CT images. The EBCT and micro-CT images were analyzed with the nested multi ROI method which provides an index of spatial heterogeneity of intramyocardial blood volume in terms of the linear relationship between the logarithms of the coefficient of variation within the data obtained at any one size of the ROI, and the logarithm of the volume of that selected ROI. The minimum ROI volume in the EBCT analysis was 8.96 mm³ and for the micro-CT it was 0.07 mm³. There is linear correlation when EBCT and micro-CT image CT gray-scale numbers are plotted as Log (standard deviation/mean) against Log (Volume of ROI). The results show that the slopes and offsets of the EBCT-based and micro-CT-based regression lines were indistinguishable. Moreover, when a fraction of microvessels of selected diameter was embolized, the change in the resulting regression line was characteristic for that diameter. In summary, the EBCT-based analysis spatial heterogeneity of myocardial blood volume can be extrapolated to describe the spatial distribution of the microcirculatory branching geometry in terms of intra segmental lumen volume.

Proceedings Article | 26 October 2004 Paper

A polycapillary x-ray optics-based integrated micro-SPECT/CT scanner

Steven Jorgensen, Michael Chmelik, Diane Eaker, Carolyn MacDonald, Erik Ritman

Proceedings Volume 5535, (2004) https://doi.org/10.1117/12.560991

KEYWORDS: X-ray optics, X-rays, Single photon emission computed tomography, Scanners, Photons, X-ray computed tomography, Capillaries, X-ray imaging, Radio optics, Imaging systems

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Proceedings Article | 30 April 2004 Paper

Graphical tools for improved definition of 3D arterial trees

Kun-Chang Yu, Erik Ritman, William Higgins

Proceedings Volume 5369, (2004) https://doi.org/10.1117/12.533816

KEYWORDS: 3D image processing, 3D vision, 3D displays, Image processing, Image segmentation, Feature extraction, Laser scanners, 3D scanning, Visualization, Zoom lenses

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Proceedings Article | 5 June 2003 Paper

Point spread function deconvolution in 3D micro-CT angiography for multiscale vascular tree separation

Suzanne Witt, Christian Riedel, Mario Goessl, Michael Chmelik, Erik Ritman

Proceedings Volume 5030, (2003) https://doi.org/10.1117/12.480232

KEYWORDS: Point spread functions, Deconvolution, Image segmentation, Modulation transfer functions, Angiography, Arteries, Signal to noise ratio, Visualization, Imaging systems, 3D image processing

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Proceedings Article | 2 May 2003 Paper

Toward reliable multigenerational analysis of anatomical trees in 3D high-resolution CT images

Kun-Chang Yu, Erik Ritman, Atilla Kiraly, Shu-Yen Wan, Mair Zamir, William Higgins

Proceedings Volume 5031, (2003) https://doi.org/10.1117/12.480299

KEYWORDS: 3D image processing, Image segmentation, Visualization, Computed tomography, Field emission displays, Error analysis, Data mining, Human-machine interfaces, Laser scanners, 3D scanning

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Proceedings Article | 24 April 2002 Paper

Accurate segmentation for quantitative analysis of vascular trees in 3D micro-CT images

Christian Riedel, Siang Chuah, Mair Zamir, Erik Ritman

Proceedings Volume 4683, (2002) https://doi.org/10.1117/12.463590

KEYWORDS: Image segmentation, Binary data, 3D image processing, Quantitative analysis, Data modeling, 3D modeling, Image processing algorithms and systems, Error analysis, Statistical modeling, Arteries

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Quantitative analysis of the branching geometry of multiple branching-order vascular trees from 3D micro-CT data requires an efficient segmentation algorithm that leads to a consistent, accurate representation of the tree structure. To explore different segmentation techniques, we use isotropic micro-CT-images of intact rat coronary, pulmonary and hepatic opacified arterial trees with cubic voxel-side length of 5-20 micrometer. We implemented an active topology adaptive surface model for segmentation and compared the results from this algorithm with segmentations of the same image data using conventional segmentation methods. Because of the modulation transfer function of the micro-CT scanner, thresholding and region growing techniques usually underestimate small, or overestimate large, vessel diameters depending on the chosen grayscale thresholds. Furthermore, these approaches lack the robustness needed to overcome the effects of typical imaging artifacts, such as image noise at the vessel surfaces, which tend to propagate errors in the analysis of the tree due to its hierarchical nature. Our adaptable surface models include local gray- scale statistics, object boundary and object size information into the segmentation algorithm, thus leading to a higher stability and accuracy of the segmentation process. 5-20 micrometer. We implemented an active topology adaptive surface model for segmentation and compared the results from this algorithm with segmentations of the same image data using conventional segmentation methods. Because of the modulation transfer function of the micro-CT scanner, thresholding and region growing techniques usually underestimate small, or overestimate large, vessel diameters depending on the chosen grayscale thresholds. Furthermore, these approaches lack the robustness needed to overcome the e*ects of typical imaging artifacts, such as image noise at the vessel surfaces, which tend to propagate errors in the analysis of the tree due to its hierarchical nature. Our adaptable surface models include local gray-scale statistics, object boundary and object size information into the segmentation algorithm, thus leading to a higher stability and accuracy of the segmentation process.

Proceedings Article | 24 April 2002 Paper

3D visualization of endocardial peak velocities during systole and diastole

Christian Eusemann, Erik Ritman, Richard Robb

Proceedings Volume 4683, (2002) https://doi.org/10.1117/12.463579

KEYWORDS: Heart, Image segmentation, Solid modeling, Visualization, 3D modeling, Motion models, 3D image processing, Reconstruction algorithms, 3D visualizations, Medical imaging

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Proceedings Article | 7 January 2002 Paper

Cryostatic micro-CT imaging of transient processes

Steven Jorgensen, Basil Blank, Erik Ritman

Proceedings Volume 4503, (2002) https://doi.org/10.1117/12.452837

KEYWORDS: X-rays, Nitrogen, X-ray imaging, Beryllium, Tissues, Cryogenics, Scanners, Copper, Liquids, Lung

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Proceedings Article | 3 July 2001 Paper

Multigenerational analysis and visualization of large 3D vascular images

Shu-Yen Wan, Erik Ritman, William Higgins

Proceedings Volume 4322, (2001) https://doi.org/10.1117/12.431155

KEYWORDS: 3D image processing, Image analysis, Visualization, Image processing, Statistical analysis, Visual analytics, Image visualization, 3D visualizations, Medical imaging, Lithium

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Proceedings Article | 21 May 2001 Paper

3D quantitative visualization of altered LV wall thickening dynamics caused by coronary microembolization

Christian Eusemann, Stefan Mohlenkamp, Erik Ritman, Richard Robb

Proceedings Volume 4321, (2001) https://doi.org/10.1117/12.428125

KEYWORDS: Heart, Image segmentation, Visualization, 3D image processing, 3D modeling, Arteries, Computer programming, Magnetic resonance imaging, 3D visualizations, Ischemia

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Proceedings Article | 20 April 2000 Paper

Heterogeneity of coronary arterial branching geometry

Shu-Yen Wan, Denise Reyes, William Higgins, Erik Ritman

Proceedings Volume 3978, (2000) https://doi.org/10.1117/12.383435

KEYWORDS: Arteries, 3D image processing, Heart, X-rays, Veins, Charge-coupled devices, Fractal analysis, X-ray sources, Image segmentation, X-ray imaging

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Past measurements of arterial branching geometry have indicated that the branching geometry is somewhat consistent with an optimal trade-off between the work needed to build and maintain the arterial tree and the work needed to operate the tree as a transport system. The branching geometry is also consistent with the mechanism that acutely adjusts the lumen diameter by way of maintaining a constant shear stress by dilating (or constricting) the arteries via the nitric oxide mechanism. However, those observations also indicate that there is considerable variation about the predicted optimization, both within any one individual and between individuals. Possible causes for this variation include: (1) measurement noise -- both due to the imprecision of the method but also the preparation of the specimen for applying the measurement technique, (2) the fact that the measurement task presents a major logistic problem, which increases as the vessel size decreases (but the number of branches correspondingly doubles at each branching) and results in progressive under-sampling as the vessel size decreases, (3) because of the logistic task involved the number of arterial trees analyzed is also greatly limited, and (4) there may indeed be actual heterogeneity in the geometry which is due to slight variation in implementation of the 'rules' used to construct a vascular tree. Indeed, it is this latter possibility that is of considerable physiological interest as it could result in the observed heterogeneity of organ perfusion and also provide some insight into the relative importance of 'initial ' conditions (i.e., how the vascular tree initially develops during embryogenesis) and the adaptive mechanisms operative in the maturing individual. The use of micro-CT imaging to provide 3D images of the intact vascular tree within the intact organ overcomes or minimizes the logistic problems listed above. It is the purpose of this study to examine whether variability in the branching geometry is constant over the length of an artery or whether this progressively amplifies along the length of the artery.

Proceedings Article | 20 April 2000 Paper

Quantification of single-kidney glomerular filtration rate with electron-beam computed tomography

Lilach Lerman, Erik Ritman, Laura Pelaez, Patrick Sheedy, James Krier

Proceedings Volume 3978, (2000) https://doi.org/10.1117/12.383439

KEYWORDS: Kidney, Arteries, Computed tomography, Plasma, Tissues, Blood circulation, Hemodynamics, Statistical analysis, Blood, Control systems

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Proceedings Article | 20 April 2000 Paper

Volume of myocardium perfused by coronary artery branches as estimated from 3D micro-CT images of rat hearts

Patricia Lund, Lauren Naessens, Catherine Seaman, Denise Reyes, Erik Ritman

Proceedings Volume 3978, (2000) https://doi.org/10.1117/12.383412

KEYWORDS: Arteries, Heart, 3D image processing, Blood circulation, Image segmentation, X-rays, Charge-coupled devices, Polymers, Scanners, 3D metrology

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Proceedings Article | 22 September 1999 Paper

Micro-CT scanner with a focusing polycapillary x-ray optic

Steven Jorgensen, Denise Reyes, Carolyn MacDonald, Erik Ritman

Proceedings Volume 3772, (1999) https://doi.org/10.1117/12.363717

KEYWORDS: X-ray optics, X-rays, X-ray sources, Scanners, X-ray imaging, Capillaries, Crystals, Glasses, Charge-coupled devices, Geometrical optics

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Proceedings Article | 21 May 1999 Paper

Noise reduction in x-ray microtomographic images by anisotropic diffusion filtration of the scanner projection images

Omer Demirkaya, Erik Ritman

Proceedings Volume 3661, (1999) https://doi.org/10.1117/12.348625

KEYWORDS: Image filtering, Tomography, Anisotropic filtering, 3D image processing, Anisotropic diffusion, 3D image reconstruction, X-rays, Optical filters, Image resolution, X-ray imaging

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Proceedings Article | 20 May 1999 Paper

Extraction and analysis of large vascular networks in 3D micro-CT images

Shu-Yen Wan, Erik Ritman, William Higgins

Proceedings Volume 3660, (1999) https://doi.org/10.1117/12.349602

KEYWORDS: 3D image processing, Image segmentation, Image processing, 3D metrology, 3D scanning, Liver, Image filtering, X-ray computed tomography, Computed tomography, Laser scanners

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Proceedings Article | 24 October 1997 Paper

Synchrotron-based micro-CT of in-situ biological basic functional units and their integration

Erik Ritman, Steven Jorgensen, Patricia Beighley, Paul Thomas, John Dunsmuir, J. Romero, Russell Turner, Mark Bolander

Proceedings Volume 3149, (1997) https://doi.org/10.1117/12.279356

KEYWORDS: X-rays, 3D image processing, Synchrotrons, X-ray imaging, Scanners, Tomography, Reconstruction algorithms, Spatial resolution, Heart, X-ray computed tomography

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Proceedings Article | 9 May 1997 Paper

Heterogeneity of myocardial fatty acid tracer uptake in the porcine heart wall

Erik Ritman, Patricia Beighley

Proceedings Volume 3033, (1997) https://doi.org/10.1117/12.274043

KEYWORDS: Blood, Heart, Cameras, Mode conditioning cables, Computed tomography, Image analysis, Tomography, Arteries, Scanners, Oxidation

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Proceedings Article | 8 April 1996 Paper

Acute effects of delayed reperfusion following myocardial infarction: a 3D x-ray imaging analysis

Robert Simari, M. Bell, Y. Pao, B. Gersh, Erik Ritman

Proceedings Volume 2709, (1996) https://doi.org/10.1117/12.237880

KEYWORDS: Blood, Arteries, Heart, 3D image processing, Blood circulation, Animal model studies, X-ray imaging, Hemodynamics, Image analysis, Computed tomography

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Proceedings Article | 8 April 1996 Paper

Three-dimensional x-ray imaging of the anatomy and function of the lungs and pulmonary arteries in dogs following single lung transplant

Qing-Hua Wu, Christopher McGregor, Xue-Si Wu, Mauro Rinaldi, Folke Nilsson, Henry Tazelaar, Erik Ritman

Proceedings Volume 2709, (1996) https://doi.org/10.1117/12.237897

KEYWORDS: Lung, Arteries, Transplantation, Computed tomography, Scanners, Heart, X-ray computed tomography, 3D image processing, Video, X-ray imaging

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Proceedings Article | 8 April 1996 Paper

Dynamics of intramyocardial blood volume in the intact animal: evaluation with SPECT

Thomas Behrenbeck, Michael O'Connor, David Foley, Erik Ritman

Proceedings Volume 2709, (1996) https://doi.org/10.1117/12.237876

KEYWORDS: Blood, Single photon emission computed tomography, Heart, Signal attenuation, Electrocardiography, Scanners, Tomography, In vivo imaging, Magnesium, Echocardiography

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Proceedings Article | 8 April 1996 Paper

Noninvasive coronary artery angiography using electron beam computed tomography

John Rumberger, Benno Rensing, Judd Reed, Erik Ritman, Patrick Sheedy

Proceedings Volume 2709, (1996) https://doi.org/10.1117/12.237853

KEYWORDS: Angiography, Arteries, Tomography, Image segmentation, Heart, 3D image processing, Electron beams, Computed tomography, Databases, Spatial resolution

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Proceedings Article | 24 May 1995 Paper

Splanchnic microcirculation-evaluation with whole body computed tomography

Erik Ritman, Denise Pagel, Patricia Beighley

Proceedings Volume 2433, (1995) https://doi.org/10.1117/12.209723

KEYWORDS: Computed tomography, Tissues, Liver, Heart, Blood, Image analysis, Spleen, Lung, Kidney, Abdomen

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Proceedings Article | 24 May 1995 Paper

Coronary artery stenosis detection with holographic display of 3D angiograms

Erik Ritman, Todd Schwanke, Robert Simari, Robert Schwartz, Paul Thomas

Proceedings Volume 2433, (1995) https://doi.org/10.1117/12.209725

KEYWORDS: 3D image processing, Arteries, Angiography, Holography, 3D displays, Heart, Holograms, Image processing, 3D vision, Computed tomography

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Proceedings Article | 24 May 1995 Paper

In-vivo assessment of perfusion: methods and pitfalls

Erik Ritman

Proceedings Volume 2433, (1995) https://doi.org/10.1117/12.209720

KEYWORDS: Image analysis, In vivo imaging, Image processing, Statistical analysis, Mathematical modeling, Tissues, Image resolution, Positron emission tomography, Single photon emission computed tomography, Ultrasonography

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Proceedings Article | 1 May 1994 Paper

Scan timing considerations in indicator dilution analysis of dynamic CT image sequences

Erik Ritman

Proceedings Volume 2168, (1994) https://doi.org/10.1117/12.174395

KEYWORDS: Computed tomography, Heart, Scanners, X-ray computed tomography, Signal to noise ratio, Physiology, Superposition, Image processing, Signal attenuation, Tissues

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Proceedings Article | 1 May 1994 Paper

Multidimensional cardiac imaging in retrospect

Erik Ritman

Proceedings Volume 2168, (1994) https://doi.org/10.1117/12.174387

KEYWORDS: Heart, Cardiac imaging, 3D image processing, 3D displays, Image intensifiers, Tomography, Image quality, 3D metrology, Image processing, Video

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Proceedings Article | 29 July 1993 Paper

Three-dimensional reconstruction of the coronary arterial tree geometry--rationale and recent progress

Erik Ritman

Proceedings Volume 1905, (1993) https://doi.org/10.1117/12.148643

KEYWORDS: Arteries, Scanners, Angiography, 3D image processing, Image segmentation, X-rays, X-ray computed tomography, 3D scanning, Heart, Image resolution

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Proceedings Article | 1 June 1991 Paper

Automatic analysis system for three-dimensional angiograms

William Higgins, Wolfgang Spyra, Ronald Karwoski, Erik Ritman

Proceedings Volume 1445, (1991) https://doi.org/10.1117/12.45225

KEYWORDS: Arteries, Angiography, 3D image processing, Image segmentation, Visualization, Image processing, Human-machine interfaces, 3D scanning, Image filtering, Error analysis

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Proceedings Article | 1 January 1991 Paper

Dynamic spatial reconstructor: a high-speed, stop-action, 3-D, digital radiographic imager of moving internal organs and blood

Steven Jorgensen, S. Whitlock, Paul Thomas, R. Roessler, Erik Ritman

Proceedings Volume 1346, (1991) https://doi.org/10.1117/12.23346

KEYWORDS: X-rays, Imaging systems, Cameras, X-ray imaging, Video, Charge-coupled devices, High speed photography, Velocimetry, Heart, 3D image reconstruction

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Proceedings Article | 1 May 1990 Paper

3-D image-enhancement technique for volumetric cardiac images

William Higgins, Erik Ritman

Proceedings Volume 1245, (1990) https://doi.org/10.1117/12.19551

KEYWORDS: Digital filtering, 3D image processing, Image filtering, Nonlinear filtering, Image processing, Image enhancement, 3D image enhancement, X-ray imaging, X-rays, Biomedical optics

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Showing 5 of 60 publications

Conference Committee Involvement (19)

Developments in X-Ray Tomography X

29 August 2016 | San Diego, California, United States

Developments in X-Ray Tomography IX

19 August 2014 | San Diego, California, United States