Dr. Richard L. VanMetter Profile

Dr. Richard L. VanMetter

Medical Imaging Physics Consultant

SPIE Involvement:

Author | Editor | Instructor

Area of Expertise:

Radiographic Medical Imaging , Image Processing , Technology Evaluation , Radiographic Imaging Detectors , Imaging System Analysis (MTF,NPS, DQE) , Research & Development Strategy

Websites:

Company Website

Richard VanMetter has worked in radiographic imaging for over 30 years. His primary research interests have been in imaging system analysis and image processing. He currently consultants for clients on research and development strategies in selected areas of radiographic imaging, particularly digital radiographic acquisition, image processing and display applications including: projection radiography, dual-energy, cone-beam tomography and tomosynthesis. He holds 11 patents, has contributed to or edited 8 books and written more than 70 research papers. Recognition for his work includes the Eastman Innovation Award, the SPIE Outstanding Achievement Award, two RSNA Scientific Exhibit Awards, an SPIE Medical Imaging Poster Award and the C.E.K. Mees Award for Scientific Excellence. He earned a Ph.D. in Physics at the University of Rochester. Dr. VanMetter is an emeritus member of the American Association of Physicists in Medicine.

Proceedings Article | 20 March 2007 Paper

Development and implementation of a high-performance cardiac-gated dual-energy imaging system

N. Shkumat, J. Siewerdsen, A. Dhanantwari, D. Williams, S. Richard, D. Tward, N. Paul, J. Yorkston, R. Van Metter

Proceedings Volume 6510, 651006 (2007) https://doi.org/10.1117/12.713680

KEYWORDS: Imaging systems, X-rays, Radiography, Lung, Heart, Diagnostics, Oximeters, Image filtering, Image processing, Sensors

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Proceedings Article | 16 March 2007 Paper

Configuration of AEC kVp dependence for digital radiography systems

Weidong Huang, Richard Van Metter, Chang-Ying Yang, John Yorkston

Proceedings Volume 6510, 651017 (2007) https://doi.org/10.1117/12.714377

KEYWORDS: Sensors, Signal detection, Signal to noise ratio, Receptors, X-rays, Calibration, Radiography, X-ray detectors, Interference (communication), Absorption

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Proceedings Article | 13 March 2007 Paper

The variability of software scoring of the CDMAM phantom associated with a limited number of images

Chang-Ying Yang, Richard Van Metter

Proceedings Volume 6510, 65100C (2007) https://doi.org/10.1117/12.713655

KEYWORDS: Error analysis, Data modeling, Statistical modeling, Statistical analysis, Visualization, Digital mammography, Data acquisition, Image quality, Visibility, Solids

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Proceedings Article | 2 March 2006 Paper

Applying a proposed definition for receptor dose to digital projection images

Richard Van Metter, John Yorkston

Proceedings Volume 6142, 614219 (2006) https://doi.org/10.1117/12.650136

KEYWORDS: Receptors, Image segmentation, Calibration, Sensors, Radiography, X-rays, Image processing, Standards development, Chromium, Chest

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Digital radiographs are currently characterized in terms of a variety of incompatible, vendor-specific dose metrics, which make it difficult for users to monitor receptor dose. AAPM Task Group #116 has been formed to "Standardize an Image Receptor Dose Index for Digital Radiography," prompting the publication of a proposed definition for receptor dose that can be readily implemented on any system that acquires a projection x-ray image and produces a display-ready image.¹ This paper carries that work forward by demonstrating the applicability of that proposal to a range of digital detector types and to a new set of clinical images. Digital receptor dose can be usefully defined for the four ISO beam qualities, in terms of the exposure needed to produce a specified display response in a displayed image, analogous to the ISO speed definition for screen-film images. It requires that the system produce an original image (calibrated in terms of the relationship between system response and exposure for the standard set of x-ray beam qualities defined by ISO-9236-1) and a display-ready image (represented as DICOM GSDF p-values). The receptor dose is computed in terms of the median of pixels in the original image that corresponds to near midrange pixels in the display-ready image. The exposure responses of Gd₂O₂S-, CsI(Tl)-, a-Se-, and BaFBrI-based digital radiography acquisition systems, as well as a commonly used Gd₂O₂S screen-film combination, have been measured for the four ISO beam qualities. The proposed receptor dose metric was computed for a sample of 602 clinical images for which body-part thickness technique factors (kV, mAs, and SID) were known. Analysis of this data demonstrates that the proposed receptor dose can be a useful predictor of exposure adequacy over a wide range of body parts and thickness. In conclusion, the proposed vendor-independent receptor dose metric has been shown to produce consistent results across a representative range of digital receptor technologies for a wide range of clinical images. It has also been shown to produce results that are consistent with existing standards for screen-film technology and thereby provides a measurement capable of bridging the transition to digital imaging.

Proceedings Article | 2 March 2006 Paper

High-performance dual-energy imaging with a flat-panel detector: imaging physics from blackboard to benchtop to bedside

J. Siewerdsen, N. Shkumat, A. Dhanantwari, D. Williams, S. Richard, M. Daly, N. Paul, D. Moseley, D. Jaffray, J. Yorkston, R. Van Metter

Proceedings Volume 6142, 61421E (2006) https://doi.org/10.1117/12.658080

KEYWORDS: Imaging systems, Sensors, Image acquisition, Oximeters, Dual energy imaging, Lung, Radiography, Diagnostics, Silver, X-rays

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The application of high-performance flat-panel detectors (FPDs) to dual-energy (DE) imaging offers the potential for dramatically improved detection and characterization of subtle lesions through reduction of "anatomical noise," with applications ranging from thoracic imaging to image-guided interventions. In this work, we investigate DE imaging performance from first principles of image science to preclinical implementation, including: 1.) generalized task-based formulation of NEQ and detectability as a guide to system optimization; 2.) measurements of imaging performance on a DE imaging benchtop; and 3.) a preclinical system developed in our laboratory for cardiac-gated DE chest imaging in a research cohort of 160 patients. Theoretical and benchtop studies directly guide clinical implementation, including the advantages of double-shot versus single-shot DE imaging, the value of differential added filtration between low- and high-kVp projections, and optimal selection of kVp pairs, filtration, and dose allocation. Evaluation of task-based NEQ indicates that the detectability of subtle lung nodules in double-shot DE imaging can exceed that of single-shot DE imaging by a factor of 4 or greater. Filter materials are investigated that not only harden the high-kVp beam (e.g., Cu or Ag) but also soften the low-kVp beam (e.g., Ce or Gd), leading to significantly increased contrast in DE images. A preclinical imaging system suitable for human studies has been constructed based upon insights gained from these theoretical and experimental studies. An important component of the system is a simple and robust means of cardiac-gated DE image acquisition, implemented here using a fingertip pulse oximeter. Timing schemes that provide cardiac-gated image acquisition on the same or successive heartbeats is described. Preclinical DE images to be acquired under research protocol will afford valuable testing of optimal deployment, facilitate the development of DE CAD, and support comparison of DE diagnostic imaging performance to low-dose CT and radiography.

Proceedings Article | 2 March 2006 Paper

Applying the European protocol for the quality control of the physical and technical aspects of mammography screening threshold contrast visibility assessment to digital systems

Richard Van Metter, Michael Heath, Lynn Fletcher-Heath

Proceedings Volume 6142, 614205 (2006) https://doi.org/10.1117/12.650141

KEYWORDS: Failure analysis, Digital mammography, Visualization, Gold, Target detection, Visibility, Statistical analysis, Error analysis, Image quality, Mammography

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The need to assure the image quality of digital systems for mammography screening applications is now widely recognized. One approach is embodied in Part B of the European Protocol for the Quality Control of the Physical and Technical Aspects of Mammography Screening (EPQCM), which prescribes criteria for several interconnected image quality metrics. The focus of this study is on the "threshold contrast visibility" (TCV) protocol (section 2.4.1 of the EPQCM), in which human observers score images of a CDMAM or similar 4-AFC phantom. This section of the EPQCM currently omits many critical experimental details, which must be gleaned from ancillary documents. Given these, the purpose of this study is to quantify the effects of several remaining experimental variables, including phantom design, and the methods used for scoring and analysis, on the measured results. Preliminary studies of two CDMAM version 3.4 (CDMAM 3.4) phantoms have revealed a 17% difference in TCV when averaged over all target diameters from 0.1 to 2.0 mm. This indicates phantom variability may affect results at some sites. More importantly, we have shown that the current CDMAM phantom design, methods for scoring, and analysis, substantially limit the ability to measure system performance accurately and precisely. An improved phantom design has been shown to avoid these limitations. Viewing environment and presentation context affect the performance and efficiency of visual scoring of phantom images. An automated display tool has been developed that isolates individual 4-AFC targets of CDMAM phantom images, automatically optimizes window/level, and automatically records observers' scores. While not substantially changing TCV, the tool has increased scoring efficiency while mitigating several of the limitations associated with unassisted visual scoring. For example, learning bias and navigational issues are completely avoided. Ultimately, software-based ideal observer scoring will likely prove to be a better approach. Statistical-decision-theory-based (SDT) analysis has been shown to mitigate limitations associated with the current CDMAM phantom and the ad hoc nearest-neighbor correcting (NNC) scoring method. NNC analysis is sensitive to the degree of incomplete scoring (stopping criteria). However, SDT substantially mitigates this problem, using all of the available data to derive thresholds that are more interpretable. Bootstrap sampling was used to provide an estimate of the standard error for SDT analysis. In conclusion, the current EPQCM section 2.4.1 protocol fails to measure TCV accurately and precisely enough to qualify digital mammography systems. This paper presents a series of recommendations that supplement section 2.4.1 of the EPQCM and that provide a stable and accurate measure of TCV.

Proceedings Article | 20 April 2005 Paper

Toward a universal definition of speed for digitally acquired projection images

Richard Van Metter, John Yorkston

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.595606

KEYWORDS: Image processing, Radiography, X-rays, Sensors, Calibration, Imaging systems, Standards development, Chromium, X-ray imaging, Collimation

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Proceedings Article | 20 April 2005 Paper

Quantifying the performance of human and software CDMAM phantom image observers for the qualification of digital mammography systems

Lynn Fletcher-Heath, Richard Van Metter

Proceedings Volume 5745, (2005) https://doi.org/10.1117/12.595510

KEYWORDS: Visualization, Statistical analysis, Electronic design automation, Visual analytics, Digital mammography, Error analysis, Image quality, Data modeling, Digital imaging, Contrast sensitivity

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Proceedings Article | 5 June 2003 Paper

Standardization of NPS measurement: interim report of AAPM TG16

Andrew Maidment, Michael Albert, Phillip Bunch, Ian Cunningham, James Dobbins, Robert Gagne, Robert Nishikawa, Richard Van Metter, Robert Wagner

Proceedings Volume 5030, (2003) https://doi.org/10.1117/12.480451

KEYWORDS: Sensors, X-rays, Standards development, Diagnostics, Imaging systems, Imaging devices, Calibration, Signal detection, Medical imaging, Spatial frequencies

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Proceedings Article | 28 June 2001 Paper

Comprehensive and automated image quality performance measurement of computed radiography systems

Xiaohui Wang, Richard Van Metter, David Foos, David Steklenski

Proceedings Volume 4320, (2001) https://doi.org/10.1117/12.430889

KEYWORDS: Image quality, Chromium, Modulation transfer functions, X-rays, Copper, Tolerancing, Radiography, Scanners, Computing systems, Image processing

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Proceedings Article | 28 June 2001 Paper

Factors influencing image quality in digital radiographic systems

Richard Van Metter, John Yorkston

Proceedings Volume 4320, (2001) https://doi.org/10.1117/12.430923

KEYWORDS: Modulation transfer functions, Sensors, Imaging systems, Spatial frequencies, Image processing, Radiography, X-rays, Systems modeling, Image quality, Stochastic processes

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Proceedings Article | 26 June 2001 Paper

Influence of enhanced visual processing (EVP) of chest images on workflow

Elizabeth Krupinski, Martin Radvany, Alan Levy, Daniel Ballenger, Jonathan Tucker, Anna Chacko, Richard Van Metter

Proceedings Volume 4324, (2001) https://doi.org/10.1117/12.431175

KEYWORDS: Image processing, Chest, Chromium, Diagnostics, Visualization, Picture Archiving and Communication System, Cameras, Zoom lenses, Information visualization, Image enhancement

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Proceedings Article | 28 May 2001 Paper

Visual CRT sharpness estimation using a fiducial marker set

Kevin Kohm, Andrew Cameron, Richard Van Metter

Proceedings Volume 4319, (2001) https://doi.org/10.1117/12.428067

KEYWORDS: CRTs, Visualization, Modulation transfer functions, Video, Cameras, Calibration, Modulation, Statistical analysis, CCD cameras, Manufacturing

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SPIE Press Book | 16 February 2000

Handbook of Medical Imaging, Volume 1. Physics and Psychophysics

KEYWORDS: X-rays, Sensors, Signal detection, Visualization, Radiology, Medical imaging, Ultrasonography, X-ray imaging

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Handbook of Medical Imaging, Volume 1. Physics and Psychophysics

Proceedings Article | 26 May 1999 Paper

Sensitivity of visual targets for display quality assessment

Richard Van Metter, Binsheng Zhao, Kevin Kohm

Proceedings Volume 3658, (1999) https://doi.org/10.1117/12.349437

KEYWORDS: Modulation transfer functions, Visualization, Target detection, Image quality, Calibration, CRTs, Image display, Medical imaging, Printing, Image visualization

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Proceedings Article | 26 May 1999 Paper

Enhanced latitude for digital projection radiography

Richard Van Metter, David Foos

Proceedings Volume 3658, (1999) https://doi.org/10.1117/12.349459

KEYWORDS: Image processing, Diagnostics, Radiography, Image enhancement, Image quality, X-rays, Chest, Process control, X-ray imaging, Image visualization

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Proceedings Article | 26 June 1998 Paper

New automatic tone-scale method for computed radiography

Lori Barski, Richard Van Metter, David Foos, Hsien-Che Lee, Xiaohui Wang

Proceedings Volume 3335, (1998) https://doi.org/10.1117/12.312489

KEYWORDS: Image processing, Abdomen, Radiography, Diagnostics, Image segmentation, Chest, Chromium, Image quality, Process control, Statistical analysis

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Proceedings Article | 16 April 1997 Paper

Visual optimization of radiographic tone scale

Hsien-Che Lee, Scott Daly, Richard Van Metter

Proceedings Volume 3036, (1997) https://doi.org/10.1117/12.271284

KEYWORDS: Visualization, X-rays, Radiography, X-ray imaging, Visual process modeling, Image quality, Image transmission, Systems modeling, Visibility, Diagnostics

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Proceedings Article | 16 April 1997 Paper

Visual study of perceptually optimized displays

Richard Van Metter, Thomas Kocher

Proceedings Volume 3036, (1997) https://doi.org/10.1117/12.271307

KEYWORDS: Visualization, Medical imaging, Spine, Nonimpact printing, Radiography, Sensors, Calibration, Standards development, Diagnostics, Visual process modeling

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Proceedings Article | 8 May 1995 Paper

Sensitivity of radiographic screens to scattered radiation

Kwok Yip, Bruce Whiting, Thomas Kocher, David Trauernicht, Richard Van Metter

Proceedings Volume 2432, (1995) https://doi.org/10.1117/12.208360

KEYWORDS: Photons, X-rays, Chromium, Systems modeling, Absorption, Data modeling, Signal detection, Radiography, Computing systems, Sensors

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Proceedings Article | 14 September 1993 Paper

Performance characteristics of a flexible antiscatter grid used in computed radiography

Richard Van Metter, David Trauernicht, David Steklenski

Proceedings Volume 1896, (1993) https://doi.org/10.1117/12.154600

KEYWORDS: Radiography, Transmittance, X-rays, Lead, Signal to noise ratio, Aluminum, Physics, Medical imaging, Ionization, Sensors

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Proceedings Article | 1 June 1992 Paper

Exposure latitude for thoracic radiography

Richard Van Metter, Henri Lemmers, Leo Schultze Kool

Proceedings Volume 1651, (1992) https://doi.org/10.1117/12.59384

KEYWORDS: X-rays, Transmittance, Lung, Abdomen, Radiography, Heart, Chest, Receptors, Medical imaging, Imaging systems

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Proceedings Article | 1 July 1990 Paper

Analysis of the effects of depth dependence of x-ray interactions on the MTF and NPS of radiographic screens

Richard Van Metter, Majid Rabbani

Proceedings Volume 1231, (1990) https://doi.org/10.1117/12.18804

KEYWORDS: Scattering, X-rays, Modulation transfer functions, Light scattering, Stochastic processes, Image processing, Photography, X-ray imaging, Systems modeling, Imaging systems

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Proceedings Article | 1 July 1990 Paper

Conversion noise measurement for front and back x-ray intensifying screens

David Trauernicht, Richard Van Metter

Proceedings Volume 1231, (1990) https://doi.org/10.1117/12.18803

KEYWORDS: X-rays, Photons, Gadolinium, Erbium, Medical imaging, Image acquisition, Contamination, Absorption, Integrating spheres, X-ray detectors

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Proceedings Article | 1 July 1990 Paper

Low-frequency transmission of the chest in an outpatient population: implications for the AMBER imaging system

Henri Lemmers, Leo Schultze Kool, H. van Elburg, Richard Van Metter

Proceedings Volume 1231, (1990) https://doi.org/10.1117/12.18823

KEYWORDS: Chest, Lung, Abdomen, Imaging systems, Receptors, Signal attenuation, Radiology, Radiography, X-rays, Medical imaging

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Showing 5 of 25 publications

SPIE Conference Volume | 2 May 1997

Medical Imaging 1997: Physics of Medical Imaging

SPIE Conference Volume | 11 April 1996

Medical Imaging 1996: Physics of Medical Imaging

SPIE Conference Volume | 8 May 1995

Medical Imaging 1995: Physics of Medical Imaging

Conference Committee Involvement (9)

Physics of Medical Imaging

18 February 2008 | San Diego, California, United States

Physics of Medical Imaging

18 February 2007 | San Diego, CA, United States

Physics of Medical Imaging

12 February 2006 | San Diego, California, United States

Medical Imaging 2002

23 February 2002 | San Diego, United States

Medical Imaging 2001

17 February 2001 | San Diego, United States

Showing 5 of 9 Conference Committees

Course Instructor

SC1094: ImageJ Part 1: The GUI and Macro Programming with Applications to Image Processing and Image Analysis

This course is an introduction to ImageJ, an open-source freely-available Java-based image image processing and analysis application. The course will focus on two key features of ImageJ: the graphical-user interface and the macro programming language. Together these provide a very-wide range of capabilities from simple image viewing to image processing and analysis of entire directories of images. The course will include real-time demonstrations of image processing and image analysis for several medical-imaging modalities. Anyone seeking an easy-to-use, extensible environment for image viewing, manipulation, processing and analysis who is considering ImageJ will benefit from this course.

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SC1095: ImageJ Part 2: Plugin Programming with Applications to Image Processing and Image Analysis

This course is an introduction to Java object-oriented programming with application to ImageJ plugin programming. Plugins extend the capabilities of ImageJ, an open-source freely-available Java-based image processing and analysis application. They enable rapid prototyping of image processing and analysis concepts within the ImageJ wrapper, which does all of the file handling and image display, saving substantial time and effort. These can be readily shared with colleagues and clients. The course will focus on designing, programming and installing plugins for image processing and analysis applications. Real-time demonstrations will illustrate key concepts through examples from several medical-imaging modalities. Anyone seeking to extend their use of ImageJ beyond the user interface, available macros and macro-programming will benefit from this course. (Note: Course is based on the ImageJ 1.46 API)

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SC1028: Introduction to ImageJ with Applications to Image Processing and Image Analysis

This course is an introduction to ImageJ, a open-source, freely-available Java-based image processing and analysis application. ImageJ provides a convenient, easy-to-use wrapper that does all of the file handling and image display, saving substantial time and effort. The course will focus on three key features of ImageJ: the graphical-user interface, the macro programming language, and the Java-based plug-in language. Together these provide a very wide range of capabilities from simple image viewing to rapid prototyping of an image processing concept. Real-time demonstrations will include examples from image processing and image analysis for several radiographic modalities. Anyone seeking an easy-to-use, extensible environment for image viewing, manipulation, processing and analysis who is considering ImageJ will benefit from this course.

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