keyword
MENU ▼
Read by QxMD icon Read
search

iterative model reconstruction

keyword
https://www.readbyqxmd.com/read/28214228/coronary-artery-stent-evaluation-with-model-based-iterative-reconstruction-at-coronary-ct-angiography
#1
Fuminari Tatsugami, Toru Higaki, Hiroaki Sakane, Wataru Fukumoto, Yoko Kaichi, Makoto Iida, Yasutaka Baba, Masao Kiguchi, Yasuki Kihara, So Tsushima, Kazuo Awai
RATIONALE AND OBJECTIVES: This study aims to compare the image quality of coronary artery stent scans on computed tomography images reconstructed with forward projected model-based iterative reconstruction solution (FIRST) and adaptive iterative dose reduction 3D (AIDR 3D). MATERIALS AND METHODS: Coronary computed tomography angiography scans of 23 patients with 32 coronary stents were used. The images were reconstructed with AIDR 3D and FIRST. We generated computed tomography attenuation profiles across the stents and measured the width of the edge rise distance and the edge rise slope (ERS)...
February 14, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28207398/acoustic-classification-and-optimization-for-multi-modal-rendering-of-real-world-scenes
#2
Carl Schissler, Christian Loftin, Dinesh Manocha
We present a novel algorithm to generate virtual acoustic effects in captured 3D models of real-world scenes for multimodal augmented reality. We leverage recent advances in 3D scene reconstruction in order to automatically compute acoustic material properties. Our technique consists of a two-step procedure that first applies a convolutional neural network (CNN) to estimate the acoustic material properties, including frequency-dependent absorption coefficients, that are used for interactive sound propagation...
February 9, 2017: IEEE Transactions on Visualization and Computer Graphics
https://www.readbyqxmd.com/read/28205113/cardiac-pet-ct-with-rb-82-optimization-of-image-acquisition-and-reconstruction-parameters
#3
P Chilra, S Gnesin, G Allenbach, M Monteiro, J O Prior, L Vieira, J A Pires Jorge
BACKGROUND: Our aim was to characterize the influence of time-of-flight (TOF) and point spread function (PSF) recovery corrections, as well as ordered subset expectation maximization (OSEM) reconstruction parameters, in (82)Rb PET/CT quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR). Rest and stress list-mode dynamic (82)Rb PET acquisition data from 10 patients without myocardial flow defects and 10 patients with myocardial blood flow defects were reconstructed retrospectively...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28204857/low-dose-ct-imaging-of-a-total-hip-arthroplasty-phantom-using-model-based-iterative-reconstruction-and-orthopedic-metal-artifact-reduction
#4
R H H Wellenberg, M F Boomsma, J A C van Osch, A Vlassenbroek, J Milles, M A Edens, G J Streekstra, C H Slump, M Maas
OBJECTIVE: To compare quantitative measures of image quality, in terms of CT number accuracy, noise, signal-to-noise-ratios (SNRs), and contrast-to-noise ratios (CNRs), at different dose levels with filtered-back-projection (FBP), iterative reconstruction (IR), and model-based iterative reconstruction (MBIR) alone and in combination with orthopedic metal artifact reduction (O-MAR) in a total hip arthroplasty (THA) phantom. MATERIALS AND METHODS: Scans were acquired from high- to low-dose (CTDIvol: 40...
February 15, 2017: Skeletal Radiology
https://www.readbyqxmd.com/read/28200212/head-to-head-comparison-of-adaptive-statistical-and-model-based-iterative-reconstruction-algorithms-for-submillisievert-coronary-ct-angiography
#5
Dominik C Benz, Tobias A Fuchs, Christoph Gräni, Annina A Studer Bruengger, Olivier F Clerc, Fran Mikulicic, Michael Messerli, Julia Stehli, Mathias Possner, Aju P Pazhenkottil, Oliver Gaemperli, Philipp A Kaufmann, Ronny R Buechel
No abstract text is available yet for this article.
February 15, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28195833/a-generalized-framework-unifying-image-registration-and-respiratory-motion-models-and-incorporating-image-reconstruction-for-partial-image-data-or-full-images
#6
Jamie R McClelland, Marc Modat, Simon Arridge, Helen Grimes, Derek D'Souza, David Thomas, Dylan O'Connell, Daniel Low, Evangelia Kaza, David Collins, Martin Leach, David Hawkes
Surrogate-driven respiratory motion models relate the motion of the internal anatomy to easily acquired respiratory surrogate signals, such as the motion of the skin surface. They are usually built by first using image registration to determine the motion from a number of dynamic images, and then fitting a correspondence model relating the motion to the surrogate signals. In this paper we present a generalized framework that unifies the image registration and correspondence model fitting into a single optimization...
February 14, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28185433/model-based-iterative-reconstruction-for-single-shot-epi-at-7t
#7
Uten Yarach, Myung-Ho In, Itthi Chatnuntawech, Berkin Bilgic, Frank Godenschweger, Hendrik Mattern, Alessandro Sciarra, Oliver Speck
PURPOSE: To describe a model-based reconstruction strategy for single-shot echo planar imaging (EPI) that intrinsically accounts for k-space nonuniformity, Nyquist ghosting, and geometric distortions during rather than before or after image reconstruction. METHODS: Ramp sampling and inhomogeneous B0 field-induced distortion cause the EPI samples to lie on a non-Cartesian grid, thus requiring the nonuniform fast Fourier transform. Additionally, a 2D Nyquist ghost phase correction without the need for extra navigator acquisition is included in the proposed reconstruction...
February 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28183974/on-the-deep-mantle-origin-of-the-deccan-traps
#8
Petar Glišović, Alessandro M Forte
The Deccan Traps in west-central India constitute one of Earth's largest continental flood basalt provinces, whose eruption played a role in the Cretaceous-Paleogene extinction event. The unknown mantle structure under the Indian Ocean at the start of the Cenozoic presents a challenge for connecting the event to a deep mantle origin. We used a back-and-forth iterative method for time-reversed convection modeling, which incorporates tomography-based, present-day mantle heterogeneity to reconstruct mantle structure at the start of the Cenozoic...
February 10, 2017: Science
https://www.readbyqxmd.com/read/28177655/iterative-image-reconstruction-improves-the-accuracy-of-automated-plaque-burden-assessment-in-coronary-ct-angiography-a-comparison-with-intravascular-ultrasound
#9
Stefan B Puchner, Maros Ferencik, Akiko Maehara, Paul Stolzmann, Shixin Ma, Synho Do, Hans-Ulrich Kauczor, Gary S Mintz, Udo Hoffmann, Christopher L Schlett
OBJECTIVE: The purpose of this study was to determine whether use of iterative image reconstruction algorithms improves the accuracy of coronary CT angiography (CCTA) compared with intravascular ultrasound (IVUS) in semiautomated plaque burden assessment. MATERIALS AND METHODS: CCTA and IVUS images of seven coronary arteries were acquired ex vivo. CT images were reconstructed with filtered back projection (FBP) and adaptive statistical (ASIR) and model-based (MBIR) iterative reconstruction algorithms...
February 8, 2017: AJR. American Journal of Roentgenology
https://www.readbyqxmd.com/read/28170300/effect-of-radiation-dose-reduction-and-reconstruction-algorithm-on-image-noise-contrast-resolution-and-detectability-of-subtle-hypoattenuating-liver-lesions-at-multidetector-ct-filtered-back-projection-versus-a-commercial-model-based-iterative-reconstruction
#10
Justin Solomon, Daniele Marin, Kingshuk Roy Choudhury, Bhavik Patel, Ehsan Samei
Purpose To determine the effect of radiation dose and iterative reconstruction (IR) on noise, contrast, resolution, and observer-based detectability of subtle hypoattenuating liver lesions and to estimate the dose reduction potential of the IR algorithm in question. Materials and Methods This prospective, single-center, HIPAA-compliant study was approved by the institutional review board. A dual-source computed tomography (CT) system was used to reconstruct CT projection data from 21 patients into six radiation dose levels (12...
February 7, 2017: Radiology
https://www.readbyqxmd.com/read/28156203/feasibility-of-iterative-model-reconstruction-for-unenhancedlumbar-ct
#11
Yuji Iyama, Takeshi Nakaura, Ayumi Iyama, Masafumi Kidoh, Kazuhiro Katahira, Seitaro Oda, Daisuke Utsunomiya, Yasuyuki Yamashita
Purpose To evaluate the image quality and interobserver reproducibility of unenhanced lumbar spinal computed tomography (CT) images reconstructed with iterative model reconstruction (IMR). Materials and Methods This prospective study was approved by the local ethics committee, and written informed consent was obtained from all patients. The study included 34 patients scanned with unenhanced CT and magnetic resonance (MR) imaging for lumbar canal spinal stenosis. The CT images were reconstructed with filtered back projection (FBP), hybrid iterative reconstruction (HIR), and IMR...
February 2, 2017: Radiology
https://www.readbyqxmd.com/read/28113890/speckle-reduction-in-3d-optical-coherence-tomography-of-retina-by-a-scan-reconstruction
#12
Jun Cheng, Dacheng Tao, Ying Quan, Damon Wing Kee Wong, Gemmy Chui Ming Cheung, Masahiro Akiba, Jiang Liu
Optical coherence tomography (OCT) is a micrometer-scale, cross-sectional imaging modality for biological tissue. It has been widely used for retinal imaging in ophthalmology. Speckle noise is problematic in OCT. A raw OCT image/volume usually has very poor image quality due to speckle noise, which often obscures the retinal structures. Overlapping scan is often used for speckle reduction in a 2D line-scan. However, it leads to an increase of the data acquisition time. Therefore, it is unpractical in 3D scan as it requires a much longer data acquisition time...
April 20, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28113807/a-kernel-density-estimator-based-maximum-a-posteriori-image-reconstruction-method-for-dynamic-emission-tomography-imaging
#13
Alvin Ihsani, Troy Farncombe
A novel maximum a posteriori (MAP) method for dynamic SPECT image reconstruction is proposed. The prior probability is modelled as a multivariate kernel density estimator (KDE), effectively modelling the prior probability nonparametrically, with the aim of reducing the effects of artifacts arising from inconsistencies in projection measurements in lowcount regimes where projections are dominated by noise. The proposed prior spatially and temporally limits the variation of time-activity functions (TAF) and "attracts" similar TAFs together...
March 25, 2016: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28113359/modeling-and-pre-treatment-of-photon-starved-ct-data-for-iterative-reconstruction
#14
Zhiqian Chang, Ruoqiao Zhang, Jean-Baptiste Thibault, Debashish Pal, Lin Fu, Ken Sauer, Charles Bouman
An increasing number of X-ray CT procedures are being conducted with drastically reduced dosage, due at least in part to advances in statistical reconstruction methods that can deal more effectively with noise than can traditional techniques. As data become photon-limited, more detailed models are necessary to deal with count rates that drop to the levels of system electronic noise. We present two options for sinogram pre-treatment that can improve the performance of photonstarved measurements, with the intent of following with modelbased image reconstruction...
September 7, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28103283/orthogonal-procrustes-analysis-for-dictionary-learning-in-sparse-linear-representation
#15
Giuliano Grossi, Raffaella Lanzarotti, Jianyi Lin
In the sparse representation model, the design of overcomplete dictionaries plays a key role for the effectiveness and applicability in different domains. Recent research has produced several dictionary learning approaches, being proven that dictionaries learnt by data examples significantly outperform structured ones, e.g. wavelet transforms. In this context, learning consists in adapting the dictionary atoms to a set of training signals in order to promote a sparse representation that minimizes the reconstruction error...
2017: PloS One
https://www.readbyqxmd.com/read/28099224/comparison-of-model-based-iterative-reconstruction-adaptive-statistical-iterative-reconstruction-and-filtered-back-projection-for-detecting-hepatic-metastases-on-submillisievert-low-dose-computed-tomography
#16
Jung Hee Son, Seung Ho Kim, Jung-Hee Yoon, Yedaun Lee, Yun-Jung Lim, Seon-Jeong Kim
OBJECTIVE: The aim of the study was to compare the diagnostic performance of model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP) on submillisievert low-dose computed tomography (LDCT) for detecting hepatic metastases. METHODS: Thirty-eight patients having hepatic metastases underwent abdomen CT. Computed tomography protocol consisted of routine standard-dose portal venous phase scan (120 kVp) and 90-second delayed low-dose scan (80 kVp)...
January 18, 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28086901/gpu-accelerated-voxel-driven-forward-projection-for-iterative-reconstruction-of-cone-beam-ct
#17
Yi Du, Gongyi Yu, Xincheng Xiang, Xiangang Wang
BACKGROUND: For cone-beam computed tomography (CBCT), which has been playing an important role in clinical applications, iterative reconstruction algorithms are able to provide advantageous image qualities over the classical FDK. However, the computational speed of iterative reconstruction is a notable issue for CBCT, of which the forward projection calculation is one of the most time-consuming components. METHOD AND RESULTS: In this study, the cone-beam forward projection problem using the voxel-driven model is analysed, and a GPU-based acceleration method for CBCT forward projection is proposed with the method rationale and implementation workflow detailed as well...
January 5, 2017: Biomedical Engineering Online
https://www.readbyqxmd.com/read/28081011/spectrum-reconstruction-method-based-on-the-detector-response-model-calibrated-by-x-ray-fluorescence
#18
Ruizhe Li, Liang Li, Zhiqiang Chen
Accurate estimation of distortion-free spectra is important but difficult in various applications, especially for spectral computed tomography. Two key problems must be solved to reconstruct the incident spectrum. One is the acquisition of the detector energy response. It can be calculated by Monte Carlo simulation, which requires detailed modeling of the detector system and a high computational power. It can also be acquired by establishing a parametric response model and be calibrated using monochromatic x-ray sources, such as synchrotron sources or radioactive isotopes...
February 7, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28066840/task-based-design-of-fluence-field-modulation-in-ct-for-model-based-iterative-reconstruction
#19
Grace J Gang, Jeffrey H Siewerdsen, J Webster Stayman
A task-driven imaging framework for prospective fluence field modulation (FFM) is developed in this paper. The design approach uses a system model that includes a parameterized FFM acquisition and model-based iterative reconstruction (MBIR) for image formation. Using prior anatomical knowledge (e.g. from a low-dose 3D scout image), accurate predictions of spatial resolution and noise as a function of FFM are integrated into a task-based objective function. Specifically, detectability index (d'), a common metric for task-based image quality assessment, is computed for a specific formulation of the imaging task...
July 2016: Conference Proceedings of International Conference on Image Formation in X-Ray Computed Tomography
https://www.readbyqxmd.com/read/28065380/iterative-model-reconstruction-reduces-calcified-plaque-volume-in-coronary-ct-angiography
#20
Mihály Károlyi, Bálint Szilveszter, Márton Kolossváry, Richard A P Takx, Csilla Celeng, Andrea Bartykowszki, Ádám L Jermendy, Alexisz Panajotu, Júlia Karády, Rolf Raaijmakers, Walter Giepmans, Béla Merkely, Pál Maurovich-Horvat
OBJECTIVE: To assess the impact of iterative model reconstruction (IMR) on calcified plaque quantification as compared to filtered back projection reconstruction (FBP) and hybrid iterative reconstruction (HIR) in coronary computed tomography angiography (CTA). METHODS: Raw image data of 52 patients who underwent 256-slice CTA were reconstructed with IMR, HIR and FBP. We evaluated qualitative, quantitative image quality parameters and quantified calcified and partially calcified plaque volumes using automated software...
February 2017: European Journal of Radiology
keyword
keyword
109395
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"