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https://www.readbyqxmd.com/read/28458443/renal-stone-characterization-using-high-resolution-imaging-mode-on-a-photon-counting-detector-ct-system
#1
A Ferrero, R Gutjahr, A Henning, S Kappler, A Halaweish, D Abdurakhimova, Z Peterson, J Montoya, S Leng, C McCollough
In addition to the standard-resolution (SR) acquisition mode, a high-resolution (HR) mode is available on a research photon-counting-detector (PCD) whole-body CT system. In the HR mode each detector consists of a 2x2 array of 0.225 mm × 0.225 mm subpixel elements. This is in contrast to the SR mode that consists of a 4x4 array of the same sub-elements, and results in 0.25 mm isotropic resolution at iso-center for the HR mode. In this study, we quantified ex vivo the capabilities of the HR mode to characterize renal stones in terms of morphology and mineral composition...
March 9, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736474/phenotype-analysis-of-early-risk-factors-from-electronic-medical-records-improves-image-derived-diagnostic-classifiers-for-optic-nerve-pathology
#2
Shikha Chaganti, Kunal P Nabar, Katrina M Nelson, Louise A Mawn, Bennett A Landman
We examine imaging and electronic medical records (EMR) of 588 subjects over five major disease groups that affect optic nerve function. An objective evaluation of the role of imaging and EMR data in diagnosis of these conditions would improve understanding of these diseases and help in early intervention. We developed an automated image-processing pipeline that identifies the orbital structures within the human eyes from computed tomography (CT) scans, calculates structural size, and performs volume measurements...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736473/theoretical-and-empirical-comparison-of-big-data-image-processing-with-apache-hadoop-and-sun-grid-engine
#3
Shunxing Bao, Frederick D Weitendorf, Andrew J Plassard, Yuankai Huo, Aniruddha Gokhale, Bennett A Landman
The field of big data is generally concerned with the scale of processing at which traditional computational paradigms break down. In medical imaging, traditional large scale processing uses a cluster computer that combines a group of workstation nodes into a functional unit that is controlled by a job scheduler. Typically, a shared-storage network file system (NFS) is used to host imaging data. However, data transfer from storage to processing nodes can saturate network bandwidth when data is frequently uploaded/retrieved from the NFS, e...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736472/a-radiative-transfer-equation-based-image-reconstruction-method-incorporating-boundary-conditions-for-diffuse-optical-imaging
#4
Abhinav K Jha, Yansong Zhu, Dean F Wong, Arman Rahmim
Developing reconstruction methods for diffuse optical imaging requires accurate modeling of photon propagation, including boundary conditions arising due to refractive index mismatch as photons propagate from the tissue to air. For this purpose, we developed an analytical Neumann-series radiative transport equation (RTE)-based approach. Each Neumann series term models different scattering, absorption, and boundary-reflection events. The reflection is modeled using the Fresnel equation. We use this approach to design a gradient-descent-based analytical reconstruction algorithm for a three-dimensional (3D) setup of a diffuse optical imaging (DOI) system...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736471/comparison-of-multi-fiber-reproducibility-of-pas-mri-and-q-ball-with-empirical-multiple-b-value-hardi
#5
Vishwesh Nath, Kurt G Schilling, Justin A Blaber, Zhaohua Ding, Adam W Anderson, Bennett A Landman
Crossing fibers are prevalent in human brains and a subject of intense interest for neuroscience. Diffusion tensor imaging (DTI) can resolve tissue orientation but is blind to crossing fibers. Many advanced diffusion-weighted magnetic resolution imaging (MRI) approaches have been presented to extract crossing-fibers from high angular resolution diffusion imaging (HARDI), but the relative sensitivity and specificity of approaches remains unclear. Here, we examine two leading approaches (PAS and q-ball) in the context of a large-scale, single subject reproducibility study...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736470/structural-functional-relationships-between-eye-orbital-imaging-biomarkers-and-clinical-visual-assessments
#6
Xiuya Yao, Shikha Chaganti, Kunal P Nabar, Katrina Nelson, Andrew Plassard, Rob L Harrigan, Louise A Mawn, Bennett A Landman
Eye diseases and visual impairment affect millions of Americans and induce billions of dollars in annual economic burdens. Expounding upon existing knowledge of eye diseases could lead to improved treatment and disease prevention. This research investigated the relationship between structural metrics of the eye orbit and visual function measurements in a cohort of 470 patients from a retrospective study of ophthalmology records for patients (with thyroid eye disease, orbital inflammation, optic nerve edema, glaucoma, intrinsic optic nerve disease), clinical imaging, and visual function assessments...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736469/improved-automatic-optic-nerve-radius-estimation-from-high-resolution-mri
#7
Robert L Harrigan, Alex K Smith, Louise A Mawn, Seth A Smith, Bennett A Landman
The optic nerve (ON) is a vital structure in the human visual system and transports all visual information from the retina to the cortex for higher order processing. Due to the lack of redundancy in the visual pathway, measures of ON damage have been shown to correlate well with visual deficits. These measures are typically taken at an arbitrary anatomically defined point along the nerve and do not characterize changes along the length of the ON. We propose a fully automated, three-dimensionally consistent technique building upon a previous independent slice-wise technique to estimate the radius of the ON and surrounding cerebrospinal fluid (CSF) on high-resolution heavily T2-weighted isotropic MRI...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736468/multi-atlas-spleen-segmentation-on-ct-using-adaptive-context-learning
#8
Jiaqi Liu, Yuankai Huo, Zhoubing Xu, Albert Assad, Richard G Abramson, Bennett A Landman
Automatic spleen segmentation on CT is challenging due to the complexity of abdominal structures. Multi-atlas segmentation (MAS) has shown to be a promising approach to conduct spleen segmentation. To deal with the substantial registration errors between the heterogeneous abdominal CT images, the context learning method for performance level estimation (CLSIMPLE) method was previously proposed. The context learning method generates a probability map for a target image using a Gaussian mixture model (GMM) as the prior in a Bayesian framework...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28736467/stability-of-gradient-field-corrections-for-quantitative-diffusion-mri
#9
Baxter P Rogers, Justin Blaber, E Brian Welch, Zhaohua Ding, Adam W Anderson, Bennett A Landman
In magnetic resonance diffusion imaging, gradient nonlinearity causes significant bias in the estimation of quantitative diffusion parameters such as diffusivity, anisotropy, and diffusion direction in areas away from the magnet isocenter. This bias can be substantially reduced if the scanner- and coil-specific gradient field nonlinearities are known. Using a set of field map calibration scans on a large (29 cm diameter) phantom combined with a solid harmonic approximation of the gradient fields, we predicted the obtained b-values and applied gradient directions throughout a typical field of view for brain imaging for a typical 32-direction diffusion imaging sequence...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28690357/federating-heterogeneous-datasets-to-enhance-data-sharing-and-experiment-reproducibility
#10
Juan C Prieto, Beatriz Paniagua, Marilia S Yatabe, Antonio C O Ruellas, Liana Fattori, Luciana Muniz, Martin Styner, Lucia Cevidanes
Recent studies have demonstrated the difficulties to replicate scientific findings and/or experiments published in past.(1) The effects seen in the replicated experiments were smaller than previously reported. Some of the explanations for these findings include the complexity of the experimental design and the pressure on researches to report positive findings. The International Committee of Medical Journal Editors (ICMJE) suggests that every study considered for publication must submit a plan to share the de-identified patient data no later than 6 months after publication...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28690356/diagnostic-index-an-open-source-tool-to-classify-tmj-oa-condyles
#11
Beatriz Paniagua, Laura Pascal, Juan Prieto, Jean Baptiste Vimort, Liliane Gomes, Marilia Yatabe, Antonio Carlos Ruellas, Francois Budin, Steve Pieper, Martin Styner, Erika Benavides, Lucia Cevidanes
Osteoarthritis (OA) of temporomandibular joints (TMJ) occurs in about 40% of the patients who present TMJ disorders. Despite its prevalence, OA diagnosis and treatment remain controversial since there are no clear symptoms of the disease, especially in early stages. Quantitative tools based on 3D imaging of the TMJ condyle have the potential to help characterize TMJ OA changes. The goals of the tools proposed in this study are to ultimately develop robust imaging markers for diagnosis and assessment of treatment efficacy...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28690355/evaluation-of-lung-tumor-motion-management-in-radiation-therapy-with-dynamic-mri
#12
Seyoun Park, Rana Farah, Steven M Shea, Erik Tryggestad, Russell Hales, Junghoon Lee
Surrogate-based tumor motion estimation and tracing methods are commonly used in radiotherapy despite the lack of continuous real time 3D tumor and surrogate data. In this study, we propose a method to simultaneously track the tumor and external surrogates with dynamic MRI, which allows us to evaluate their reproducible correlation. Four MRI-compatible fiducials are placed on the patient's chest and upper abdomen, and multi-slice 2D cine MRIs are acquired to capture the lung and whole tumor, followed by two-slice 2D cine MRIs to simultaneously track the tumor and fiducials, all in sagittal orientation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28663663/design-optimization-for-accurate-flow-simulations-in-3d-printed-vascular-phantoms-derived-from-computed-tomography-angiography
#13
Kelsey Sommer, Richard L Izzo, Lauren Shepard, Alexander R Podgorsak, Stephen Rudin, Adnan H Siddiqui, Michael F Wilson, Erin Angel, Zaid Said, Michael Springer, Ciprian N Ionita
3D printing has been used to create complex arterial phantoms to advance device testing and physiological condition evaluation. Stereolithographic (STL) files of patient-specific cardiovascular anatomy are acquired to build cardiac vasculature through advanced mesh-manipulation techniques. Management of distal branches in the arterial tree is important to make such phantoms practicable. We investigated methods to manage the distal arterial flow resistance and pressure thus creating physiologically and geometrically accurate phantoms that can be used for simulations of image-guided interventional procedures with new devices...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28659654/real-time-implementation-of-anti-scatter-grid-artifact-elimination-method-for-high-resolution-x-ray-imaging-cmos-detectors-using-graphics-processing-units-gpus
#14
R Rana, S V Setlur Nagesh, D R Bednarek, S Rudin
Scatter is one of the most important factors effecting image quality in radiography. One of the best scatter reduction methods in dynamic imaging is an anti-scatter grid. However, when used with high resolution imaging detectors these grids may leave grid-line artifacts with increasing severity as detector resolution improves. The presence of such artifacts can mask important details in the image and degrade image quality. We have previously demonstrated that, in order to remove these artifacts, one must first subtract the residual scatter that penetrates through the grid followed by dividing out a reference grid image; however, this correction must be done fast so that corrected images can be provided in real-time to clinicians...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649159/initial-simulated-ffr-investigation-using-flow-measurements-in-patient-specific-3d-printed-coronary-phantoms
#15
Lauren Shepard, Kelsey Sommer, Richard Izzo, Alexander Podgorsak, Michael Wilson, Zaid Said, Frank J Rybicki, Dimitrios Mitsouras, Stephen Rudin, Erin Angel, Ciprian N Ionita
PURPOSE: Accurate patient-specific phantoms for device testing or endovascular treatment planning can be 3D printed. We expand the applicability of this approach for cardiovascular disease, in particular, for CT-geometry derived benchtop measurements of Fractional Flow Reserve, the reference standard for determination of significant individual coronary artery atherosclerotic lesions. MATERIALS AND METHODS: Coronary CT Angiography (CTA) images during a single heartbeat were acquired with a 320×0...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649158/implementation-of-material-decomposition-using-an-emccd-and-cmos-based-micro-ct-system
#16
Alexander R Podgorsak, Sv Setlur Nagesh, Daniel R Bednarek, Stephen Rudin, Ciprian N Ionita
This project assessed the effectiveness of using two different detectors to obtain dual-energy (DE) micro-CT data for the carrying out of material decomposition. A micro-CT coupled to either a complementary metal-oxide semiconductor (CMOS) or an electron multiplying CCD (EMCCD) detector was used to acquire image data of a 3D-printed phantom with channels filled with different materials. At any instance, materials such as iohexol contrast agent, water, and platinum were selected to make up the scanned object...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649157/use-of-patient-specific-3d-printed-neurovascular-phantoms-to-evaluate-the-clinical-utility-of-a-high-resolution-x-ray-imager
#17
S V Setlur Nagesh, M Russ, C N Ionita, D Bednarek, S Rudin
Modern 3D printing technology can fabricate vascular phantoms based on an actual human patient with a high degree of precision facilitating a realistic simulation environment for an intervention. We present two experimental setups using 3D printed patient-specific neurovasculature to simulate different disease anatomies. To simulate the human neurovasculature in the Circle of Willis, patient-based phantoms with aneurysms were 3D printed using a Objet Eden 260V printer. Anthropomorphic head phantoms and a human skull combined with acrylic plates simulated human head bone anatomy and x-ray attenuation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649156/multi-atlas-segmentation-enables-robust-multi-contrast-mri-spleen-segmentation-for-splenomegaly
#18
Yuankai Huo, Jiaqi Liu, Zhoubing Xu, Robert L Harrigan, Albert Assad, Richard G Abramson, Bennett A Landman
Non-invasive spleen volume estimation is essential in detecting splenomegaly. Magnetic resonance imaging (MRI) has been used to facilitate splenomegaly diagnosis in vivo. However, achieving accurate spleen volume estimation from MR images is challenging given the great inter-subject variance of human abdomens and wide variety of clinical images/modalities. Multi-atlas segmentation has been shown to be a promising approach to handle heterogeneous data and difficult anatomical scenarios. In this paper, we propose to use multi-atlas segmentation frameworks for MRI spleen segmentation for splenomegaly...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649155/evaluation-of-methods-to-produce-an-image-library-for-automatic-patient-model-localization-for-dose-mapping-during-fluoroscopically-guided-procedures
#19
Josh Kilian-Meneghin, Z Xiong, A Oines, S Rudin, D R Bednarek
The purpose of this work is to evaluate methods for producing a library of 2D-radiographic images to be correlated to clinical images obtained during a fluoroscopically-guided procedure for automated patient-model localization. The localization algorithm will be used to improve the accuracy of the skin-dose map superimposed on the 3D patient-model of the real-time Dose-Tracking-System (DTS). For the library, 2D images were generated from CT datasets of the SK-150 anthropomorphic phantom using two methods: Schmid's 3D-visualization tool and Plastimatch's digitally-reconstructed-radiograph (DRR) code...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649154/skin-dose-mapping-for-non-uniform-x-ray-fields-using-a-backscatter-point-spread-function
#20
Sarath Vijayan, Zhenyu Xiong, Alok Shankar, Stephen Rudin, Daniel R Bednarek
Beam shaping devices like ROI attenuators and compensation filters modulate the intensity distribution of the x-ray beam incident on the patient. This results in a spatial variation of skin dose due to the variation of primary radiation and also a variation in backscattered radiation from the patient. To determine the backscatter component, backscatter point spread functions (PSF) are generated using EGS Monte-Carlo software. For this study, PSF's were determined by simulating a 1 mm beam incident on the lateral surface of an anthropomorphic head phantom and a 20 cm thick PMMA block phantom...
February 11, 2017: Proceedings of SPIE
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