ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019
Field-emission x-ray source arrays have been studied for both tomosynthesis and CT applications, however these arrays tend to have limited output. We propose the use of multi-source x-ray arrays using thermionic cathodes, contained within a single vacuum h ...
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Journal ArticleRadiology · January 2017
Purpose To conduct a multi-institutional, multireader study to compare the performance of digital tomosynthesis, dual-energy (DE) imaging, and conventional chest radiography for pulmonary nodule detection and management. Materials and Methods In this binat ...
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Journal ArticleMed Phys · January 2016
PURPOSE: To create a database of highly realistic and anatomically variable 3D virtual breast phantoms based on dedicated breast computed tomography (bCT) data. METHODS: A tissue classification and segmentation algorithm was used to create realistic and de ...
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Chapter · October 1, 2014
Attention to matters of safety is important in any imaging facility. In the context of the developing world, limited resources may complicate the attempt to set up and operate an imaging facility with the highest standards of safety, but it is nonetheless ...
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Journal ArticleIEEE Trans Med Imaging · July 2014
Featured Publication
Mammography is currently the most widely utilized tool for detection and diagnosis of breast cancer. However, in women with dense breast tissue, tissue overlap may obscure lesions. Digital breast tomosynthesis can reduce tissue overlap. Furthermore, imagin ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014
Featured Publication
Breast imaging is an important area of research with many new Techniques being investigated To further reduce The morbidity and mortality of breast cancer Through early detection. Computerized phantoms can provide an essential Tool To quantitatively compar ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014
Featured Publication
Correlated-polarity noise reduction (CPNR) is a novel noise reduction technique that uses a statistical approach to reducing noise while maintaining excellent spatial resolution and a traditional noise appearance. It was demonstrated in application to CT i ...
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Journal ArticleMed Phys · September 2013
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PURPOSE: The most common metrics for resolution analysis in medical imaging are valid only for (approximately) linear systems. While analogues to these metrics have been used in attempts to describe resolution performance in nonlinear systems, the analysis ...
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Journal ArticleMed Phys · April 2013
PURPOSE: The authors previously reported on a three-dimensional computer-generated breast phantom, based on empirical human image data, including a realistic finite-element based compression model that was capable of simulating multimodality imaging data. ...
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Journal ArticleMed Phys · February 2013
PURPOSE: Matrix inversion tomosynthesis (MITS) uses linear systems theory and knowledge of the imaging geometry to remove tomographic blur that is present in conventional backprojection tomosynthesis reconstructions, leaving in-plane detail rendered clearl ...
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ConferenceMedical Physics · January 1, 2013
Purpose: This work improves the accuracy and realism of automated breast computed tomography (bCT) tissue segmentation by refining the detection of low‐contrast fibroglandular structures to produce high‐resolution realistic computer‐generated (XCAT) breast ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Correlated-polarity noise reduction (CPNR) is a novel noise reduction technique that uses a statistical approach to reduce noise while maintaining excellent resolution and a "normal" noise appearance. It is applicable to any type of medical imaging, and we ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Physical phantoms are essential for the development, optimization, and clinical evaluation of x-ray systems. These phantoms are used for various tests such as quality assurance testing, system characterization, reconstruction evaluation, and dosimetry. The ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Assessment of the resolution properties of nonlinear imaging systems is a useful but challenging task. While the modulation transfer function (MTF) fully describes contrast resolution as a function of spatial frequency for linear systems, an equivalent met ...
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Journal ArticleMed Phys · November 2012
Featured Publication
PURPOSE: Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system modulation transfer function, noise power spectrum, detective quantum efficiency, and the expos ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2019
Field-emission x-ray source arrays have been studied for both tomosynthesis and CT applications, however these arrays tend to have limited output. We propose the use of multi-source x-ray arrays using thermionic cathodes, contained within a single vacuum h ...
Full textCite
Journal ArticleRadiology · January 2017
Purpose To conduct a multi-institutional, multireader study to compare the performance of digital tomosynthesis, dual-energy (DE) imaging, and conventional chest radiography for pulmonary nodule detection and management. Materials and Methods In this binat ...
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Journal ArticleMed Phys · January 2016
PURPOSE: To create a database of highly realistic and anatomically variable 3D virtual breast phantoms based on dedicated breast computed tomography (bCT) data. METHODS: A tissue classification and segmentation algorithm was used to create realistic and de ...
Full textLink to itemCite
Chapter · October 1, 2014
Attention to matters of safety is important in any imaging facility. In the context of the developing world, limited resources may complicate the attempt to set up and operate an imaging facility with the highest standards of safety, but it is nonetheless ...
Full textCite
Journal ArticleIEEE Trans Med Imaging · July 2014
Featured Publication
Mammography is currently the most widely utilized tool for detection and diagnosis of breast cancer. However, in women with dense breast tissue, tissue overlap may obscure lesions. Digital breast tomosynthesis can reduce tissue overlap. Furthermore, imagin ...
Full textLink to itemCite
ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014
Featured Publication
Breast imaging is an important area of research with many new Techniques being investigated To further reduce The morbidity and mortality of breast cancer Through early detection. Computerized phantoms can provide an essential Tool To quantitatively compar ...
Full textCite
Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · January 1, 2014
Featured Publication
Correlated-polarity noise reduction (CPNR) is a novel noise reduction technique that uses a statistical approach to reducing noise while maintaining excellent spatial resolution and a traditional noise appearance. It was demonstrated in application to CT i ...
Full textCite
Journal ArticleMed Phys · September 2013
Featured Publication
PURPOSE: The most common metrics for resolution analysis in medical imaging are valid only for (approximately) linear systems. While analogues to these metrics have been used in attempts to describe resolution performance in nonlinear systems, the analysis ...
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Journal ArticleMed Phys · April 2013
PURPOSE: The authors previously reported on a three-dimensional computer-generated breast phantom, based on empirical human image data, including a realistic finite-element based compression model that was capable of simulating multimodality imaging data. ...
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Journal ArticleMed Phys · February 2013
PURPOSE: Matrix inversion tomosynthesis (MITS) uses linear systems theory and knowledge of the imaging geometry to remove tomographic blur that is present in conventional backprojection tomosynthesis reconstructions, leaving in-plane detail rendered clearl ...
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ConferenceMedical Physics · January 1, 2013
Purpose: This work improves the accuracy and realism of automated breast computed tomography (bCT) tissue segmentation by refining the detection of low‐contrast fibroglandular structures to produce high‐resolution realistic computer‐generated (XCAT) breast ...
Full textCite
Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Correlated-polarity noise reduction (CPNR) is a novel noise reduction technique that uses a statistical approach to reduce noise while maintaining excellent resolution and a "normal" noise appearance. It is applicable to any type of medical imaging, and we ...
Full textCite
ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Physical phantoms are essential for the development, optimization, and clinical evaluation of x-ray systems. These phantoms are used for various tests such as quality assurance testing, system characterization, reconstruction evaluation, and dosimetry. The ...
Full textCite
Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2013
Featured Publication
Assessment of the resolution properties of nonlinear imaging systems is a useful but challenging task. While the modulation transfer function (MTF) fully describes contrast resolution as a function of spatial frequency for linear systems, an equivalent met ...
Full textCite
Journal ArticleMed Phys · November 2012
Featured Publication
PURPOSE: Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system modulation transfer function, noise power spectrum, detective quantum efficiency, and the expos ...
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Journal ArticleMed Phys · October 2012
PURPOSE: The modulation transfer function (MTF) of medical imaging devices is commonly reported in the form of orthogonal one-dimensional (1D) measurements made near the vertical and horizontal axes with a slit or edge test device. A more complete descript ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · May 4, 2012
Mammography is currently the most widely accepted tool for detection and diagnosis of breast cancer. However, the sensitivity of mammography is reduced in women with dense breast tissue due to tissue overlap, which may obscure lesions. Digital breast tomos ...
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Journal ArticleMed Phys · March 2012
PURPOSE: The purpose of this work is to improve the noise power spectrum (NPS), and thus the detective quantum efficiency (DQE), of computed radiography (CR) images by correcting for spatial gain variations specific to individual imaging plates. CR devices ...
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Journal ArticleJ Digit Imaging · February 2012
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The objective of this study was to implement and evaluate the performance of a biplane correlation imaging (BCI) technique aimed to reduce the effect of anatomic noise and improve the detection of lung nodules in chest radiographs. Seventy-one low-dose pos ...
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Journal ArticleMed Phys · February 2012
PURPOSE: The purpose of this study was to develop an automated lung segmentation method for computerized detection of lung nodules in digital chest tomosynthesis. METHODS: The authors collected 45 digital tomosynthesis scans and manually segmented referenc ...
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ConferenceMedical Physics · January 1, 2012
Digital breast tomosynthesis is a form of limited angle tomography, in which section (slice) images are produced from a series of discrete projection images acquired at different angles. Tomosynthesis can be useful in breast imaging by providing potentiall ...
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ConferenceMedical Physics · January 1, 2012
Purpose: In this work, we report on the novel application of an opaque edge test device for practical estimation of the 2‐D modulation transfer function (MTF) of a digital flat panel (DFP) detector. Methods: We estimated the 2‐ D MTF of a prototype GE Revo ...
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ConferenceMedical Physics · January 1, 2012
Digital tomosynthesis is a form of limited angle tomography, in which section (slice) images are produced from a series of discrete projection images acquired at different angles. The simplest form of tomosynthesis reconstruction is the shift‐and‐add techn ...
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Journal ArticleMed Phys · October 2011
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PURPOSE: The authors previously introduced a methodology to generate a realistic three-dimensional (3D), high-resolution, computer-simulated breast phantom based on empirical data. One of the key components of such a phantom is that it provides a means to ...
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Journal ArticlePhys Med Biol · August 21, 2011
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The detective quantum efficiency (DQE) and the effective DQE (eDQE) are relevant metrics of image quality for digital radiography detectors and systems, respectively. The current study further extends the eDQE methodology to technique optimization using a ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011
Reduction of image noise is an important goal in producing the highest quality medical images. A very important benefit of reducing image noise is the ability to reduce patient exposure while maintaining adequate image quality. Various methods have been de ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011
This paper describes a recently developed post-acquisition motion correction strategy for application to lower-cost computed tomography (LCCT) for under-resourced regions of the world. Increased awareness regarding global health and its challenges has enco ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · May 13, 2011
Current clinical image quality assessment techniques mainly analyze image quality for the imaging system in terms of factors such as the capture system DQE and MTF, the exposure technique, and the particular image processing method and processing parameter ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · December 1, 2010
This paper describes an initial investigation into means for producing lower-cost CT scanners for resource limited regions of the world. In regions such as sub-Saharan Africa, intermediate level medical facilities serving millions have no CT machines, and ...
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ConferenceMedical Physics · January 1, 2010
Purpose: To improve the NPS, and thus DQE, of CR images by correcting for pixel‐to‐pixel gain variations specific to each plate. Method and Materials: Ten high‐exposure, open field images were taken with an RQA5 spectrum, with a sixth generation CR plate s ...
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Journal ArticleEur J Radiol · November 2009
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Digital tomosynthesis is a radiographic technique that can produce an arbitrary number of section images of a patient from a single pass of the X-ray tube. It utilizes a conventional X-ray tube, a flat-panel detector, a computer-controlled tube mover, and ...
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Journal ArticleMed Phys · August 2009
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Prior studies on performance evaluation of digital radiographic systems have primarily focused on the assessment of the detector performance alone. However, the clinical performance of such systems is also substantially impacted by magnification, focal spo ...
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Journal ArticleMed Phys · July 2009
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The initial process for creating a flexible three-dimensional computer-generated breast phantom based on empirical data is described. Dedicated breast computed-tomography data were processed to suppress noise and scatter artifacts in the reconstructed imag ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009
In digital radiography, conventional DQE evaluations are performed under idealized conditions that do not reflect typical clinical operating conditions. For this reason, we have developed and evaluated an experimental methodology for measuring the effectiv ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 15, 2009
We previously proposed a three-dimensional computerized breast phantom that combines empirical data with the flexibility of mathematical models1. The goal of this project is to enhance the breast phantom to include a more detailed anatomy than currently vi ...
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Journal ArticleMed Phys · June 2009
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Tomosynthesis is a decades-old technique for section imaging that has seen a recent upsurge in interest due to its promise to provide three-dimensional information at lower dose and potentially lower cost than CT in certain clinical imaging situations. Thi ...
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Journal ArticleMed Phys · May 2009
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Matrix inversion tomosynthesis (MITS) uses known imaging geometry and linear systems theory to deterministically separate in-plane detail from residual tomographic blur in a set of conventional tomosynthesis ("shift-and-add") planes. A previous investigati ...
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ConferenceMedical Physics · January 1, 2009
Every medical physicist is a teacher, either formally in the classroom or informally in the clinic. Some physicists skillfully fulfill their educational obligations, while others struggle with their teaching responsibilities. However, everyone can be a goo ...
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Journal ArticleRadiology · December 2008
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PURPOSE: To develop an experimental method for measuring the effective detective quantum efficiency (eDQE) of digital radiographic imaging systems and evaluate its use in select imaging systems. MATERIALS AND METHODS: A geometric phantom emulating the atte ...
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Journal ArticleMed Phys · June 2008
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The authors report interim clinical results from an ongoing NIH-sponsored trial to evaluate digital chest tomosynthesis for improving detectability of small lung nodules. Twenty-one patients undergoing computed tomography (CT) to follow up lung nodules wer ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · May 14, 2008
The goal of this work is to create a detailed three-dimensional (3D) digital breast phantom based on empirical data and to incorporate it into the four-dimensional (4D) NCAT phantom, a computerized model of the human anatomy widely used in imaging research ...
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Journal ArticleJ Thorac Imaging · May 2008
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Digital tomosynthesis is a technique that generates an arbitrary number of section images of a patient from a single pass of the x-ray tube. It is under investigation for application to a number of clinical detection tasks, and has recently been implemente ...
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Journal ArticleInt J Funct Inform Personal Med · 2008
Breast cancer is second only to lung cancer as the leading cause of non-preventable cancer death in women. Digital Breast Tomosynthesis (DBT) is a promising technique to improve early breast cancer detection. In this paper, we present the impulse response ...
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Journal ArticleProceedings of the 7th IEEE International Conference on Bioinformatics and Bioengineering, BIBE · December 1, 2007
Digital breast tomosynthesis (DBT) is a three-dimensional imaging technique providing an arbitrary set of reconstruction planes in the breast with limited series of projection images. This paper describes a comparison between traditional shift-and-add (SAA ...
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ConferenceProgress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007
As a new three-dimensional imaging technique, digital breast tomosynthesis allows the reconstruction of an arbitrary set of planes in the breast from a limited-angle series of projection images. Though several tomosynthesis algorithms have been proposed, n ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · October 15, 2007
Digital tomosynthesis is an imaging technique that reconstructs tomographic planes in an object from a set of projection images taken over a fixed angle1. Preliminary results show that this technique increases the detectability of lung nodules 2. Current s ...
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Journal ArticleMed Phys · October 2007
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Digital breast tomosynthesis is a three-dimensional imaging technique that provides an arbitrary set of reconstruction planes in the breast from a limited-angle series of projection images acquired while the x-ray tube moves. Traditional shift-and-add (SAA ...
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Journal ArticleRadiology · June 2007
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PURPOSE: To prospectively evaluate the recently introduced international standard method for measurement of the detective quantum efficiency (DQE) of digital radiography systems, in comparison with representative prior methods. MATERIALS AND METHODS: A rec ...
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Journal ArticleAJR Am J Roentgenol · May 2007
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OBJECTIVE: The purpose of this study was the development and preliminary evaluation of multiprojection correlation imaging with 3D computer-aided detection (CAD) on chest radiographs for cost- and dose-effective improvement of early detection of pulmonary ...
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Journal ArticleMedical Physics · January 1, 2007
Purpose: To develop and evaluate an experimental methodology for measuring the effective detective quantum efficiency (eDQE) of digital radiographic systems which reflects the actual signal‐to‐noise performance of the system per unit exposure. Method and M ...
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ConferenceMedical Physics · January 1, 2007
Digital tomosynthesis is one of the most exciting recent developments in breast imaging. By modifying existing full field digital mammography systems, one can achieve this type of limited‐angle cone‐beam CT imaging which produces 3D slice images of the bre ...
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Journal ArticleRadiology · December 2006
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There have been many remarkable advances in conventional thoracic imaging over the past decade. Perhaps the most remarkable is the rapid conversion from film-based to digital radiographic systems. Computed radiography is now the preferred imaging modality ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006
Digital breast tomosynthesis is a three-dimensional imaging technique that allows the reconstruction of an arbitrary set of planes in the breast from limited-angle series of projection images. Though several tomosynthesis algorithms have been proposed, no ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006
Breast cancer is a major problem and the most common cancer among women. The nature of conventional mammography makes it very difficult to distinguish a cancer from overlying breast tissues. Digital Tomosynthesis refers to a three-dimensional imaging techn ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 30, 2006
Digital tomosynthesis is an imaging technique which reconstructs tomographic planes in an object from a set of projection images taken over a fixed angle [1]. Results from our initial pilot study show that tomosynthesis increases the detectability of lung ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · June 22, 2006
In this paper, we present performance of biplane correlation imaging (BCI) on set of chest x-ray projections of human data. BCI significantly minimizes the number of false positives (FPs) when used in conjunction with computer aided detection (CAD) by elim ...
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Journal ArticleMed Phys · May 2006
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Second in a two-part series comparing measurement techniques for the assessment of basic image quality metrics in digital radiography, in this paper we focus on the measurement of the image noise power spectrum (NPS). Three methods were considered: (1) a m ...
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Journal ArticleMed Phys · May 2006
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The modulation transfer function (MTF) and the noise power spectrum (NPS) are widely recognized as the most relevant metrics of resolution and noise performance in radiographic imaging. These quantities have commonly been measured using various techniques, ...
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Journal ArticleMed Phys · March 2006
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Matrix inversion tomosynthesis (MITS) uses linear systems theory, along with a priori knowledge of the imaging geometry, to deterministically distinguish between true structure and overlying tomographic blur in a set of conventional tomosynthesis planes. I ...
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ConferenceMedical Physics · January 1, 2006
Purpose: To investigate a two‐dimensional Shift‐And‐Add algorithm for three‐dimensional digital breast tomosynthsis reconstruction to correct for defects existing in the traditional Shift‐And‐Add algorithm that calculates only one‐dimensional shift amount ...
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ConferenceMedical Physics · January 1, 2006
Purpose: To evaluate a new international standard method for the measurement of detective quantum efficiency (DQE) of digital radiography systems in comparison with representative prior methods. Methods and Materials: Three DQE evaluation methods were cons ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · August 25, 2005
Digital tomosynthesis mammography algorithms allow reconstructions of arbitrary planes in the breast from limited-angle series of projection images as the x-ray source moves along an arc above the breast. Though several tomosynthesis algorithms have been p ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · August 25, 2005
We present preliminary investigations that examine the feasibility of incorporating digital tomosynthesis into radiation oncology practice with the use of kilovoltage on-board imagers (OBI). Modern radiation oncology linear accelerators now include hardwar ...
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Journal ArticleMed Phys · July 2005
As part of a larger evaluation we attempted to measure the detective quantum efficiency (DQE) of an amorphous silicon flat-panel detector using the method described in the International Electrotechnical Commission standard 62220-1 published in October 2003 ...
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Journal ArticleRadiology · June 2005
PURPOSE: To evaluate the scatter, dose, and effective detective quantum efficiency (DQE) performance of a slot-scan digital chest radiography system compared with that of a full-field digital radiography system. MATERIALS AND METHODS: Scatter fraction of a ...
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Journal ArticleMedical Physics · January 1, 2005
Tomosynthesis is a method for reconstructing 3‐dimensional (3‐D) image data from a series of x‐ray projection radiographs, acquired with limited motion of the x‐ray source (typically no more than 40 degrees). Digital tomosynthesis (DTS) is implemented with ...
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Journal ArticleProgress in Biomedical Optics and Imaging - Proceedings of SPIE · 2005
A prototype breast tomosynthesis system* has been developed, allowing a total angular view of ±25°. The detector used in this system is an amorphous selenium direct-conversion digital flat-panel detector suitable for digital tomosynthesis. The s ...
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Journal ArticleRadiat Prot Dosimetry · 2005
The transition to digital radiology has provided new opportunities for improved image quality, made possible by the superior detective quantum efficiency and post-processing capabilities of new imaging systems, and advanced imaging applications, made possi ...
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ConferenceMedical Physics · January 1, 2005
Purpose: This study introduces a new radiation therapy target localization technique using online digital tomosynthesis (DTS), a method for reconstructing 3‐D slices from 2‐D projection data acquired with limited source motion. By separating the visualizat ...
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Journal ArticleMed Phys · September 2004
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Our purpose in this study was to evaluate the fundamental image quality characteristics of a new slot-scan digital chest radiography system (ThoraScan, Delft Imaging Systems/Nucletron, Veenendaal, The Netherlands). The linearity of the system was measured ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · July 5, 2004
Purpose: Rheumatoid arthritis (RA) of the hand is a significant healthcare problem. Techniques to accurately quantity the structural changes from RA are crucial for the development and prescription of therapies. Analysis of radiographic joint space width ( ...
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Journal ArticlePhys Med Biol · October 7, 2003
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Digital x-ray tomosynthesis is a technique for producing slice images using conventional x-ray systems. It is a refinement of conventional geometric tomography, which has been known since the 1930s. In conventional geometric tomography, the x-ray tube and ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · September 15, 2003
Digital tomosynthesis is a method that enables the retroactive reconstruction of arbitrary tomographic planes in an object from a finite series of digital projection radiographs, acquired with limited angle tube movement. Conventional tomosynthesis suffers ...
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Journal ArticleMed Phys · March 2003
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The two principal forms of hand arthritis, rheumatoid arthritis (RA) and osteoarthritis (OA) have large clinical and economic costs. Radiography has been shown to be a useful tool to assess the condition of the disease. A hand radiograph, however, is a two ...
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Journal ArticleMed Phys · February 2003
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In this paper we describe a quantitative evaluation of the performance of three dual-energy noise reduction algorithms: Kalender's correlated noise reduction (KCNR), noise clipping (NOC), and edge-predictive adaptive smoothing (EPAS). These algorithms were ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · January 1, 2003
This article reviews the state of the Noise Power Standard being drafted by Task Group No. 16 for the American Association of Physicists in Medicine. The Standard is intended to represent a consensus on acceptable practices in the measurement and reporting ...
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Journal ArticleRadiology · January 2003
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PURPOSE: To ascertain the optimum x-ray spectrum for chest radiography with a cesium iodide-amorphous silicon flat-panel detector. MATERIALS AND METHODS: End points for optimization included the ratio of tissue contrast to bone contrast and a figure of mer ...
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Journal ArticleRadiology · March 2001
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PURPOSE: To evaluate the imaging characteristics of an amorphous silicon flat-panel detector (FPD) for digital chest radiography. MATERIALS AND METHODS: The 41 x 41-cm digital FPD is constructed on a single monolithic glass substrate with a structured cesi ...
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Journal ArticleProceedings of SPIE- The International Society for Optical Engineering · January 1, 2001
Joint space width (JSW) is an important arthritis outcome measure, However, a single radiographic image is a 2D projection of a 3D structure and diseased areas can be obscured. To quantify the JSW in three dimensions, a tomosynthesis algorithm was modified ...
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Journal ArticleProceedings of SPIE- The International Society for Optical Engineering · January 1, 2001
Current flat-panel detectors either directly convert x-ray energy to electronic charge or use indirect conversion with an intermediate optical process. The purpose of this work was to compare direct and indirect detectors in terms of their modulation trans ...
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Journal ArticleProceedings of SPIE- The International Society for Optical Engineering · January 1, 2001
Dual-energy subtraction imaging increases the sensitivity and specificity of pulmonary nodule detection in chest radiography by reducing the contrast of overlying bone structures. A prototype dual-energy system which enables rapid, dual-exposure imaging of ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · January 1, 2001
Digital tomosynthesis is a method for reconstructing arbitrary planes in an object from a series of projection radiographs, acquired with limited angle tube movement. Conventional 'shift and add' tomosynthesis suffers from the presence of blurring artifact ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · January 1, 2000
The improved image quality and characteristics of new flat-panel x-ray detectors have renewed interest in advanced algorithms such as tomosynthesis. Digital tomosynthesis is a method of acquiring and reconstructing a three-dimensional data set with limited ...
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Journal ArticleMed Phys · January 1999
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The performance characteristics of a photostimulable phosphor based computed radiographic (CR) system were studied. The modulation transfer function (MTF), noise power spectra (NPS), and detective quantum efficiency (DQE) of the Kodak Digital Science compu ...
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Journal ArticleIEEE Trans Med Imaging · June 1997
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A number of digital imaging techniques in medicine require the combination of multiple images. Using these techniques, it is essential that the images be adequately aligned and registered prior to addition, subtraction, or any other combination of the imag ...
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Journal ArticleMed Phys · June 1996
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We have developed a method for correcting for the scatter produced by the computed radiography plates in single-shot dual-energy imaging. In our technique, which uses a series of four computed radiography plates (the middle two plates act as a filter), the ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · December 1, 1995
We report on several new techniques which we are developing for scatter correction and noise suppression in single-shot dual-energy chest radiography. For scatter, we use a deconvolution technique to correct for the scatter produced within the dual-energy ...
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Journal ArticleMed Phys · October 1995
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Measurements were made of the MTF(f), NPS(f), and DQE(f) of four generations of computed radiography (CR) imaging plates and three generations of CR image readers. The MTF generally showed only a minor change between generations of plates and readers, but ...
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Journal ArticleMed Phys · February 1995
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The proper understanding of modulation transfer function (MTF), noise power spectra (NPS), and noise equivalent quanta (NEQ) in digital systems is significantly hampered when the systems are undersampled. Undersampling leads to three significant complicati ...
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ConferenceProceedings of SPIE - The International Society for Optical Engineering · May 11, 1994
We have reported on a single-exposure dual-energy system based on computed radiography (CR) technology. In a clinical study conducted over a two year period, the dual-energy system proved to be highly successful in improving the detection (p=0.0005) and ch ...
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Journal ArticleRadiology · April 1993
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The authors describe a variable compensation (VC) technique in which an x-ray equalizer and a computed radiography system are used. The VC technique allows retrospective alteration of equalized chest appearance with maintenance of improved signal-to-noise ...
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Journal ArticleRadiology · February 1993
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A photostimulable storage phosphor (PSP) digital radiography system was evaluated regarding the signal-to-noise ratio (S/N) on chest images acquired at differing peak kilovoltage settings but with matched risk from radiation exposure. Images of two chest p ...
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Journal ArticleRadiology · April 1992
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Images of a phantom obtained with computed radiography and standard screen-film imaging were compared to evaluate observer threshold perception performance with a modified contrast-detail technique. Optimum exposure necessary for performance with the imagi ...
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Journal ArticleMed Phys · 1992
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The authors describe a method for directly digitizing optical images with a photostimulable phosphor (PSP) system. A PSP plate is initially charged with an exposure to a uniform x-ray field, and is then exposed to an optical image which discharges the plat ...
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Journal ArticleInvest Radiol · May 1991
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A technique for simultaneously acquiring a conventional film-screen radiographic image and a digital computed radiography (CR) image with a single x-ray exposure is described. Measurements of image contrast, spatial resolution, and signal-to-noise ratios d ...
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Journal ArticleRadiology · December 1990
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Images of two phantoms were obtained with use of an advanced multiple-beam equalization radiography system, and scatter fractions were estimated with use of a photostimulable phosphor imaging system. Scatter fractions in the equalized images were lower in ...
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Journal ArticleMed Phys · 1990
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We have evaluated a photostimulable phosphor x-ray imaging system [Philips Computed Radiography (PCR) system] for use in quantification of x-ray exposure in diagnostic radiography. An exponential function was fitted to data yielding quantitative x-ray expo ...
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Journal ArticleRadiology · November 1989
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The authors describe a new technique, variable compensation (VC) radiography, for digital radiography of the chest. It permits retrospective adjustment of image display while maintaining improved mediastinal signal-to-noise ratio (S/N) from aggressive x-ra ...
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Journal ArticleMed Phys · 1987
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A digital beam attenuator system has been developed to automatically generate patient-specific compensating filters for chest radiography. An initial low-dose test image is used to generate the attenuator, which is fabricated by overprinting multiple layer ...
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Journal ArticleRadiology · May 1986
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The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, wh ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · September 19, 1985
We have used a prototype digital beam attenuator (DBA) system to generate patient-specific digitally-prepared compensating filters for chest radiography of a human subject. The compensated radiographs demonstrate substantially more information in areas suc ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · June 11, 1985
We have been testing a digital beam attenuator (DBA) system for fabricating patient- specific compensating filters to improve image quality in chest radiography. At present, the technique is limited by a 2 hour attenuator fabrication time and a 20 mR expos ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · June 11, 1985
Digital Subtraction Angiography (DSA) is commonly used in conjunction with intravenous contrast injection for detection of atherosclerotic disease in arteries outside of the heart. Images of coronary arteries obtained with intravenous DSA have been limited ...
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Journal Article · December 1, 1984
During the past year our group has investigated an extension of the concept of beam compensating filters. Our approach involves the acquisition of a low dose patient positioning image which is digitized and used to drive a mechanism which places attenuatin ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · August 28, 1984
Although image quality in chest radiography can be improved dramatically with compensat-ing attenuators, it is difficult to match attenuator geometry to that of the patient and to properly position the filter in the x-ray beam. We are developing a system w ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · June 15, 1984
The concept of selective exposure radiography encompasses those techniques which spatially modulate the incident x-ray field to produce a more uniform exit field arising from the patient. The resulting reduction in the dynamic range of the exposure field o ...
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Journal ArticleMed Phys · 1984
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An x-ray videoabsorptiometric technique was developed for measurement of bone mineral content (BMC) in vivo. The principle utility of this technique is the precise measurement of commonly fractured bones, such as the femoral neck, that are difficult to mea ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · December 13, 1983
A circuit has been constructed to perform spatial frequency filtration on DSA images at real-time video rates. The 10-bit device performs low-pass or high-pass filtering, and with external memory can perform bandpass and more sophisticated filtering. Pixel ...
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Journal ArticleJ Surg Res · June 1983
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Standard angiography demonstrates the anatomy of arterial occlusive disease but does not define its physiological significance. However, measurement of flow in a compromised vessel at rest and following peripheral dilatation provides important physiologica ...
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Journal ArticleRadiology · June 1983
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Initial clinical results using a digital fluoroscopic implementation of the combined time-energy ("hybrid") subtraction technique are described, with emphasis on carotid and renal imaging. Where patient motion artifacts are due to soft-tissue motion alone, ...
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Journal ArticleProceedings of SPIE - The International Society for Optical Engineering · December 29, 1982
In digital fluorographic techniques the video camera must accommodate a wide dynamic range due to the large variation in the infject thickness within the field of view. Typically exposure factors and the optical aperture are selected such that the maximum ...
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