James T. Dobbins III

Journal article IEEE 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 text Link to item Cite

Population of 100 realistic, patient-based computerized breast phantoms for multi-modality imaging research

Conference Progress 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 text Cite

Dose reduction in CT with correlated-polarity noise reduction: Context-dependent spatial resolution and noise properties demonstrating two-fold dose reduction with minimal artifacts

Journal article Progress 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 text Cite

Frequency response and distortion properties of nonlinear image processing algorithms and the importance of imaging context.

Journal article Med 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 ... Full text Link to item Cite

Dose reduction in CT with correlated-polarity noise reduction: Comparable image quality at half the dose with projection space processing

Journal article Progress 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 text Cite

Development of matched virtual and physical breast phantoms based on patient data

Conference Progress 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 text Cite

Preliminary investigation of the frequency response and distortion properties of nonlinear image processing algorithms

Journal article Progress 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 text Cite

An image-based technique to assess the perceptual quality of clinical chest radiographs.

Journal article Med 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 ... Full text Link to item Cite

Biplane correlation imaging: a feasibility study based on phantom and human data.

Journal article J Digit Imaging · February 2012 Featured Publication 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 ... Full text Link to item Cite

An analysis of the mechanical parameters used for finite element compression of a high-resolution 3D breast phantom.

Journal article Med Phys · October 2011 Featured Publication 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 ... Full text Link to item Cite

Effective dose efficiency: an application-specific metric of quality and dose for digital radiography.

Journal article Phys Med Biol · August 21, 2011 Featured Publication 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 ... Full text Link to item Cite

Chest tomosynthesis: technical principles and clinical update.

Journal article Eur J Radiol · November 2009 Featured Publication 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 ... Full text Link to item Cite

Effective DQE (eDQE) and speed of digital radiographic systems: an experimental methodology.

Journal article Med Phys · August 2009 Featured Publication 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 ... Full text Link to item Cite

Methodology for generating a 3D computerized breast phantom from empirical data.

Journal article Med Phys · July 2009 Featured Publication 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 ... Full text Link to item Cite

Tomosynthesis imaging: at a translational crossroads.

Journal article Med Phys · June 2009 Featured Publication 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 ... Full text Link to item Cite

Stochastic noise characteristics in matrix inversion tomosynthesis (MITS).

Journal article Med Phys · May 2009 Featured Publication 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 ... Full text Link to item Cite

Detector or system? Extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems.

Journal article Radiology · December 2008 Featured Publication 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 ... Full text Link to item Cite

Digital tomosynthesis of the chest for lung nodule detection: interim sensitivity results from an ongoing NIH-sponsored trial.

Journal article Med Phys · June 2008 Featured Publication 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 ... Full text Link to item Cite

Digital tomosynthesis of the chest.

Journal article J Thorac Imaging · May 2008 Featured Publication 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 ... Full text Link to item Cite

Importance of point-by-point back projection correction for isocentric motion in digital breast tomosynthesis: relevance to morphology of structures such as microcalcifications.

Journal article Med Phys · October 2007 Featured Publication 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 ... Full text Link to item Cite

Assessment of detective quantum efficiency: intercomparison of a recently introduced international standard with prior methods.

Journal article Radiology · June 2007 Featured Publication 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 ... Full text Link to item Cite

Multiprojection correlation imaging for improved detection of pulmonary nodules.

Journal article AJR Am J Roentgenol · May 2007 Featured Publication 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 ... Full text Link to item Cite

Recent advances in chest radiography.

Journal article Radiology · December 2006 Featured Publication 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 ... Full text Link to item Cite

Intercomparison of methods for image quality characterization. II. Noise power spectrum.

Journal article Med Phys · May 2006 Featured Publication 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 ... Full text Link to item Cite

Intercomparison of methods for image quality characterization. I. Modulation transfer function.

Journal article Med Phys · May 2006 Featured Publication 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, ... Full text Link to item Cite

Optimization of the matrix inversion tomosynthesis (MITS) impulse response and modulation transfer function characteristics for chest imaging.

Journal article Med Phys · March 2006 Featured Publication 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 ... Full text Link to item Cite

Fundamental imaging characteristics of a slot-scan digital chest radiographic system.

Journal article Med Phys · September 2004 Featured Publication 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 ... Full text Link to item Cite

Digital x-ray tomosynthesis: current state of the art and clinical potential.

Journal article Phys Med Biol · October 7, 2003 Featured Publication 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 ... Full text Link to item Cite

Digital tomosynthesis of hand joints for arthritis assessment.

Journal article Med Phys · March 2003 Featured Publication 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 ... Full text Link to item Cite

Quantitative evaluation of noise reduction strategies in dual-energy imaging.

Journal article Med Phys · February 2003 Featured Publication 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 ... Full text Link to item Cite

Chest radiography: optimization of X-ray spectrum for cesium iodide-amorphous silicon flat-panel detector.

Journal article Radiology · January 2003 Featured Publication 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 ... Full text Link to item Cite

Imaging characteristics of an amorphous silicon flat-panel detector for digital chest radiography.

Journal article Radiology · March 2001 Featured Publication 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 ... Full text Link to item Cite

Principles of digital radiography with large-area, electronically readable detectors: a review of the basics.

Journal article Radiology · March 1999 Featured Publication Full text Link to item Cite

Performance characteristics of a Kodak computed radiography system.

Journal article Med Phys · January 1999 Featured Publication 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 ... Full text Link to item Cite

A rapid and automatic image registration algorithm with subpixel accuracy.

Journal article IEEE Trans Med Imaging · June 1997 Featured Publication 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 ... Full text Link to item Cite

Plate scatter correction for improved performance in dual-energy imaging.

Journal article Med Phys · June 1996 Featured Publication 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 ... Full text Link to item Cite

DQE(f) of four generations of computed radiography acquisition devices.

Journal article Med Phys · October 1995 Featured Publication 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 ... Full text Link to item Cite

Effects of undersampling on the proper interpretation of modulation transfer function, noise power spectra, and noise equivalent quanta of digital imaging systems.

Journal article Med Phys · February 1995 Featured Publication 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 ... Full text Link to item Cite

Variable compensation chest radiography performed with a computed radiography system: design considerations and initial clinical experience.

Journal article Radiology · April 1993 Featured Publication 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 ... Full text Link to item Cite

Digital chest radiography with photostimulable storage phosphors: signal-to-noise ratio as a function of kilovoltage with matched exposure risk.

Journal article Radiology · February 1993 Featured Publication 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 ... Full text Link to item Cite

Threshold perception performance with computed and screen-film radiography: implications for chest radiography.

Journal article Radiology · April 1992 Featured Publication 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 ... Full text Link to item Cite

Direct digitization of optical images using a photostimulable phosphor system.

Journal article Med Phys · 1992 Featured Publication 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 ... Full text Link to item Cite

Single-exposure conventional and computed radiography image acquisition.

Journal article Invest Radiol · May 1991 Featured Publication 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 ... Full text Link to item Cite

Scatter fractions in AMBER imaging.

Journal article Radiology · December 1990 Featured Publication 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 ... Full text Link to item Cite

Quantitative radiographic imaging using a photostimulable phosphor system.

Journal article Med Phys · 1990 Featured Publication 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 ... Full text Link to item Cite

Variable compensation technique for digital radiography of the chest.

Journal article Radiology · November 1989 Featured Publication 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 ... Full text Link to item Cite

Geometrical properties of a digital beam attenuator system.

Journal article Med Phys · 1987 Featured Publication 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 ... Full text Link to item Cite

Digital beam attenuator technique for compensated chest radiography.

Journal article Radiology · May 1986 Featured Publication 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 ... Full text Link to item Cite

A scanning-slit x-ray videoabsorptiometric technique for bone mineral measurement.

Journal article Med Phys · 1984 Featured Publication 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 ... Full text Link to item Cite

Videodensitometric quantitation of mean blood flow.

Journal article J Surg Res · June 1983 Featured Publication 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 ... Full text Link to item Cite

Work in progress: hybrid temporal-energy subtraction in digital fluoroscopy.

Journal article Radiology · June 1983 Featured Publication 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, ... Full text Link to item Cite

QUANTITATION TECHNIQUES IN DIGITAL SUBTRACTION VIDEOANGIOGRAPHY.

Journal article Proceedings of SPIE - The International Society for Optical Engineering · 1981 Featured Publication Cite