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iterative model reconstruction

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https://www.readbyqxmd.com/read/28816669/nonlocally-multi-morphological-representation-for-image-reconstruction-from-compressive-measurements
#1
Jiao Wu, Feilong Cao, Juncheng Yin
A novel multi-morphological representation model for solving the nonlocal similarity-based image reconstruction from compressed measurements is introduced in this paper. Under the probabilistic framework, the proposed approach provides the nonlocal similarity clustering for image patches by using the Gaussian mixture models, and endows a multimorphological representation for image patches in each cluster by using the Gaussians that represent the different features to model the morphological components. Using the simple alternating iteration, the developed piecewise morphological diversity estimation (PMDE) algorithm can effectively estimate the MAP of morphological components, thus resulting in the nonlinear estimation for image patches...
August 16, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28809683/low-rank-latent-pattern-approximation-with-applications-to-robust-image-classification
#2
Shuo Chen, Jian Yang, Lei Luo, Yang Wei, Kaihua Zhang, Ying Tai
This paper develops a novel method to address the structural noise in samples for image classification. Recently, regression related classification methods have shown promising results when facing the pixel-wise noise. However, they become weak in coping with the structural noise due to ignoring of relationships between pixels of noise image. Meanwhile, most of them need to implement the iterative process for computing representation coefficients, which leads to the high time consumption. To overcome these problems, we exploit a latent pattern model called Low-Rank Latent Pattern Approximation (LLPA) to reconstruct the test image having structural noise...
August 10, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28806318/computed-tomography-image-quality-evaluation-of-a-new-iterative-reconstruction-algorithm-in-the-abdomen-adaptive-statistical-iterative-reconstruction-v-a-comparison-with-model-based-iterative-reconstruction-adaptive-statistical-iterative-reconstruction-and
#3
Martin H Goodenberger, Nicolaus A Wagner-Bartak, Shiva Gupta, Xinming Liu, Ramon Q Yap, Jia Sun, Eric P Tamm, Corey T Jensen
OBJECTIVE: The purpose of this study was to compare abdominopelvic computed tomography images reconstructed with adaptive statistical iterative reconstruction-V (ASIR-V) with model-based iterative reconstruction (Veo 3.0), ASIR, and filtered back projection (FBP). METHODS AND MATERIALS: Abdominopelvic computed tomography scans for 36 patients (26 males and 10 females) were reconstructed using FBP, ASIR (80%), Veo 3.0, and ASIR-V (30%, 60%, 90%). Mean ± SD patient age was 32 ± 10 years with mean ± SD body mass index of 26...
August 12, 2017: Journal of Computer Assisted Tomography
https://www.readbyqxmd.com/read/28774650/rapid-anatomical-brain-imaging-using-spiral-acquisition-and-an-expanded-signal-model
#4
Lars Kasper, Maria Engel, Christoph Barmet, Maximilian Haeberlin, Bertram J Wilm, Benjamin E Dietrich, Thomas Schmid, Simon Gross, David O Brunner, Klaas E Stephan, Klaas P Pruessmann
We report the deployment of spiral acquisition for high-resolution structural imaging at 7T. Long spiral readouts are rendered manageable by an expanded signal model including static off-resonance and B0 dynamics along with k-space trajectories and coil sensitivity maps. Image reconstruction is accomplished by inversion of the signal model using an extension of the iterative non-Cartesian SENSE algorithm. Spiral readouts up to 25 ms are shown to permit whole-brain 2D imaging at 0.5 mm in-plane resolution in less than a minute...
July 31, 2017: NeuroImage
https://www.readbyqxmd.com/read/28770254/3d-correction-of-ais-in-braces-designed-using-cad-cam-and-fem-a-randomized-controlled-trial
#5
Nikita Cobetto, Carl-Éric Aubin, Stefan Parent, Soraya Barchi, Isabelle Turgeon, Hubert Labelle
BACKGROUND: Recent studies showed that finite element model (FEM) combined to CAD/CAM improves the design of braces for the conservative treatment of adolescent idiopathic scoliosis (AIS), using 2D measurements from in-brace radiographs. We aim to assess the immediate effectiveness on curve correction in all three planes of braces designed using CAD/CAM and numerical simulation compared to braces designed with CAD/CAM only. METHODS: SRS standardized criteria for bracing were followed to recruit 48 AIS patients who were randomized into two groups...
2017: Scoliosis and Spinal Disorders
https://www.readbyqxmd.com/read/28767366/detector-blur-and-correlated-noise-modeling-for-digital-breast-tomosynthesis-reconstruction
#6
Jiabei Zheng, Jeffrey A Fessler, Heang-Ping Chan
This paper describes a new image reconstruction method for digital breast tomosynthesis (DBT). The new method incorporates detector blur into the forward model. The detector blur in DBT causes correlation in the measurement noise. By making a few approximations that are reasonable for breast imaging, we formulated a regularized quadratic optimization problem with a data-fit term that incorporates models for detector blur and correlated noise (DBCN). We derived a computationally efficient separable quadratic surrogate (SQS) algorithm to solve the optimization problem that has a non-diagonal noise covariance matrix...
July 27, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28766981/image-quality-and-radiation-dose-of-ct-venography-with-double-dose-reduction-using-model-based-iterative-reconstruction-comparison-with-conventional-ct-venography-using-filtered-back-projection
#7
Yeo-Jin Jeong, Ki Seok Choo, Kyung Jin Nam, Ji Won Lee, Jin You Kim, Hyuk Jae Jung, Soo Jin Lim
Background Computed tomography venography (CTV) at low kVp using model-based iterative reconstruction (MBIR) can enhance vascular enhancement with noise reduction. Purpose To evaluate image qualities and radiation doses of CTV at 80 kVp using MBIR and a small iodine contrast media (CM) dose and to compare these with those of CTV performed using a conventional protocol. Material and Methods Sixty-five patients (mean age = 58.1 ± 7.2 years) that underwent CTV for the evaluation of deep vein thrombosis (DVT) and varicose veins were enrolled in this study...
January 1, 2017: Acta Radiologica
https://www.readbyqxmd.com/read/28764856/image-quality-of-ct-angiography-in-young-children-with-congenital-heart-disease-a%C3%A2-comparison-between-the-sinogram-affirmed-iterative-reconstruction-safire-and-advanced-modelled-iterative-reconstruction-admire-algorithms
#8
S B Nam, D W Jeong, K S Choo, K J Nam, J-Y Hwang, J W Lee, J Y Kim, S J Lim
AIM: To compare the image quality of computed tomography angiography (CTA) reconstructed by sinogram-affirmed iterative reconstruction (SAFIRE) with that of advanced modelled iterative reconstruction (ADMIRE) in children with congenital heart disease (CHD). MATERIAL AND METHODS: Thirty-one children (8.23±13.92 months) with CHD who underwent CTA were enrolled. Images were reconstructed using SAFIRE (strength 5) and ADMIRE (strength 5). Objective image qualities (attenuation, noise) were measured in the great vessels and heart chambers...
July 29, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28762337/superiorized-algorithm-for-reconstruction-of-ct-images-from-sparse-view-and-limited-angle-polyenergetic-data
#9
T Humphries, J Winn, A Faridani
Recent work in CT image reconstruction has seen increasing interest in the use of total variation (TV) and related penalties to regularize problems involving reconstruction from undersampled or incomplete data. Superiorization is a recently proposed heuristic which provides an automatic procedure to 'superiorize' an iterative image reconstruction algorithm with respect to a chosen objective function, such as TV. Under certain conditions, the superiorized algorithm is guaranteed to find a solution that is as satisfactory as any found by the original algorithm with respect to satisfying the constraints of the problem; this solution is also expected to be superior with respect to the chosen objective...
August 1, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28759633/dictionary-learning-based-noisy-image-super-resolution-via-distance-penalty-weight-model
#10
Yulan Han, Yongping Zhao, Qisong Wang
In this study, we address the problem of noisy image super-resolution. Noisy low resolution (LR) image is always obtained in applications, while most of the existing algorithms assume that the LR image is noise-free. As to this situation, we present an algorithm for noisy image super-resolution which can achieve simultaneously image super-resolution and denoising. And in the training stage of our method, LR example images are noise-free. For different input LR images, even if the noise variance varies, the dictionary pair does not need to be retrained...
2017: PloS One
https://www.readbyqxmd.com/read/28756086/iterative-beam-hardening-correction-with-advanced-modeled-iterative-reconstruction-in-low-voltage-ct-coronary-calcium-scoring-with-tin-filtration-impact-on-coronary-artery-calcium-quantification-and-image-quality
#11
Christian Tesche, Carlo N De Cecco, U Joseph Schoepf, Taylor M Duguay, Moritz H Albrecht, Damiano Caruso, Akos Varga-Szemes, Virginia W Lesslie, Ullrich Ebersberger, Christian Canstein, Christian Thilo, Ellen Hoffmann, Thomas Allmendinger, John W Nance
OBJECTIVE: We investigated the impact of iterative beam-hardening correction (IBHC) with advanced modeled iterative reconstruction (ADMIRE) of ultra-low radiation-dose tin filtered (Sn100 kVp) CACS acquisitions on image quality, calcium quantification, and risk classification. METHODS: CT data of 60 patients (55% male, age 62.3 ± 9.8years) who underwent a 3rd generation dual-source CACS scan using a prospectively ECG-triggered 100 kVp sequential acquisition protocol with tin filtration (Sn100 kVp) were reconstructed using IBHC with filtered back projection (FBP) and ADMIRE with strength levels of three and five...
July 24, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/28729133/hybrid-framework-for-feasible-modeling-of-an-edge-illumination-x-ray-phase-contrast-imaging-system-at-a-human-scale
#12
Bartłomiej Włodarczyk, Jakub Pietrzak
Here, we present a hybrid approach for simulating an edge illumination X-ray phase-contrast imaging (EIXPCi) set-up using graphics processor units (GPU) with a high degree of accuracy. In this study, the applicability of pixel, mesh and non-uniform rational B-splines (NURBS) objects to carry out realistic maps of X-ray phase-contrast distribution at a human scale is accounted for by using numerical anthropomorphic phantoms and a very fast and robust simulation framework which integrates total interaction probabilities along selected X-ray paths...
July 17, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28727616/iterative-reconstruction-may-improve-diagnosis-of-gout-an-ex-vivo-bio-phantom-dual-energy-computed-tomography-study
#13
Torsten Diekhoff, Maximilian Kotlyarov, Jürgen Mews, Bernd Hamm, Kay-Geert Armin Hermann
OBJECTIVES: We hypothesize that, compared with filtered back projection (FBP), iterative reconstruction (IR) increases the detected volume of uric acid, which serves as a measure of the sensitivity of the method, and therefore allows examinations with lower radiation exposure. Thus, the aim of our study was to evaluate the role of IR in dual-energy computed tomography (DECT) for gout assessment and volumetry in an ex vivo gout model using an epoxy phantom and a biophantom. MATERIALS AND METHODS: We prepared specimens with different concentrations of monosodium uric acid in ultrasound gel (30%-50%) and inserted them into an epoxy-based phantom and a porcine foreleg...
July 19, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28715327/joint-statistical-iterative-material-image-reconstruction-for-spectral-computed-tomography-using-a-semi-empirical-forward-model
#14
Korbinian Mechlem, Sebastian Ehn, Thorsten Sellerer, Eva Braig, Daniela Munzel, Franz Pfeiffer, Peter B Noel
By acquiring tomographic measurements with several distinct photon energy spectra, spectral computed tomography (spectral CT) is able to provide additional material-specific information compared to conventional CT. This information enables the generation of material selective images, which have found various applications in medical imaging. However, material decomposition typically leads to noise amplification and a degradation of the signal-to-noise ratio. This is still a fundamental problem of spectral CT, especially for low-dose medical applications...
July 13, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28712714/spinning-slithole-collimation-for-high-sensitivity-small-animal-spect-design-and-assessment-using-gate-simulation
#15
Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
PURPOSE: While traditional collimations are widely used in preclinical SPECT imaging, they usually suffer from possessing a low system sensitivity leading to noisy images. In this study, we are aiming at introducing a novel collimator, the slithole, offering a superior resolution-sensitivity tradeoff for small animal SPECT. METHODS: The collimator was designed for a molecular SPECT scanner, the HiReSPECT. The slithole is a knife-edge narrow long aperture extended across long-axis of the camera's head...
July 13, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28712701/impact-of-advanced-modeled-iterative-reconstruction-on-interreader-agreement-in-coronary-artery-measurements
#16
Tobias Gassenmaier, Isabel Distelmaier, Andreas M Weng, Thorsten A Bley, Thorsten Klink
OBJECTIVES: To evaluate the influence of advanced modeled iterative reconstruction (ADMIRE) on coronary artery computed tomography angiography (cCTA) measurements in comparison to filtered back projection (FBP). MATERIAL AND METHODS: Phantom scans and coronary CTA studies of 27 patients were acquired with a third generation dual-source CT scanner. Images were reconstructed using FBP and ADMIRE. Phantom measurements were used as reference standard. In patient studies, representative axial slices of each coronary artery segment without (n=308) and with coronary plaques (n=40) were assessed in identical positions for comparison of FBP and ADMIRE reconstructions...
July 1, 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28707531/third-version-of-vendor-specific-model-based-iterative-reconstruction-veo-3-0-evaluation-of-ct-image-quality-in-the-abdomen-using-new-noise-reduction-presets-and-varied-slice-optimization
#17
Morgan E Telesmanich, Corey T Jensen, Jose L Enriquez, Nicolaus A Wagner-Bartak, Xinming Liu, Ott Le, Wei Wei, Adam G Chandler, Eric P Tamm
OBJECTIVE: To qualitatively and quantitatively compare abdominal CT images reconstructed with a new version of model-based iterative reconstruction (Veo 3.0; GE Healthcare) utilizing varied presets of resolution preference, noise reduction, and slice optimization. METHODS: This retrospective study was approved by our IRB and was HIPAA compliant. The raw data from 30 consecutive patients who had undergone CT abdomen scanning were used to reconstruct 4 clinical presets of 3...
July 14, 2017: British Journal of Radiology
https://www.readbyqxmd.com/read/28703922/sensitivity-evaluation-and-selective-plane-imaging-geometry-for-x-ray-induced-luminescence-imaging
#18
Bryan P Quigley, Corey D Smith, Shih-Hsun Cheng, Jeffrey S Souris, Charles A Pelizzari, Chin-Tu Chen, Leu-Wei Lo, Chester S Reft, Rodney D Wiersma, Patrick J La Riviere
PURPOSE: X-ray induced luminescence (XIL) is a hybrid X-ray/optical imaging modality that employs nanophosphors that luminescence in response to X-ray irradiation. X-ray-activated phosphorescent nanoparticles have potential applications in radiation therapy as theranostics, nanodosimeters, or radiosensitizers. Extracting clinically relevant information from the luminescent signal requires the development of a robust imaging model that can determine nanophosphor distributions at depth in an optically scattering environment from surface radiance measurements...
July 13, 2017: Medical Physics
https://www.readbyqxmd.com/read/28702482/visualization-of-simulated-small-vessels-on-computed-tomography-using-a-model-based-iterative-reconstruction-technique
#19
Toru Higaki, Fuminari Tatsugami, Chikako Fujioka, Hiroaki Sakane, Yuko Nakamura, Yasutaka Baba, Makoto Iida, Kazuo Awai
This article describes a quantitative evaluation of visualizing small vessels using several image reconstruction methods in computed tomography. Simulated vessels with diameters of 1-6 mm made by 3D printer was scanned using 320-row detector computed tomography (CT). Hybrid iterative reconstruction (hybrid IR) and model-based iterative reconstruction (MBIR) were performed for the image reconstruction.
August 2017: Data in Brief
https://www.readbyqxmd.com/read/28697576/sparse-view-image-reconstruction-via-total-absolute-curvature-combining-total-variation-for-x-ray-computed-tomography
#20
Zhizhong Zheng, Ailong Cai, Lei Li, Bin Yan, Fulong Le, Linyuan Wang, Guoen Hu
Sparse-view imaging is a promising scanning approach which has fast scanning rate and low-radiation dose in X-ray computed tomography (CT). Conventional L1-norm based total variation (TV) has been widely used in image reconstruction since the advent of compressive sensing theory. However, with only the first order information of the image used, the TV often generates dissatisfactory image for some applications. As is widely known, image curvature is among the most important second order features of images and can potentially be applied in image reconstruction for quality improvement...
July 7, 2017: Journal of X-ray Science and Technology
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