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iterative model reconstruction

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https://www.readbyqxmd.com/read/28715327/joint-statistical-iterative-material-image-reconstruction-for-spectral-computed-tomography-using-a-semi-empirical-forward-model
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
https://www.readbyqxmd.com/read/28695359/radiation-dose-reduction-for-ct-assessment-of-urolithiasis-using-iterative-reconstruction-a-prospective-intra-individual-study
#8
Annemarie M den Harder, Martin J Willemink, Pieter J van Doormaal, Frank J Wessels, M T W T Lock, Arnold M R Schilham, Ricardo P J Budde, Tim Leiner, Pim A de Jong
OBJECTIVE: To assess the performance of hybrid (HIR) and model-based iterative reconstruction (MIR) in patients with urolithiasis at reduced-dose computed tomography (CT). METHODS: Twenty patients scheduled for unenhanced abdominal CT for follow-up of urolithiasis were prospectively included. Routine dose acquisition was followed by three low-dose acquisitions at 40%, 60% and 80% reduced doses. All images were reconstructed with filtered back projection (FBP), HIR and MIR...
July 10, 2017: European Radiology
https://www.readbyqxmd.com/read/28692677/fux-sim-implementation-of-a-fast-universal-simulation-reconstruction-framework-for-x-ray-systems
#9
Monica Abella, Estefania Serrano, Javier Garcia-Blas, Ines García, Claudia de Molina, Jesus Carretero, Manuel Desco
The availability of digital X-ray detectors, together with advances in reconstruction algorithms, creates an opportunity for bringing 3D capabilities to conventional radiology systems. The downside is that reconstruction algorithms for non-standard acquisition protocols are generally based on iterative approaches that involve a high computational burden. The development of new flexible X-ray systems could benefit from computer simulations, which may enable performance to be checked before expensive real systems are implemented...
2017: PloS One
https://www.readbyqxmd.com/read/28689080/3d-reconstruction-of-the-magnetic-vector-potential-using-model-based-iterative-reconstruction
#10
K C Prabhat, K Aditya Mohan, Charudatta Phatak, Charles Bouman, Marc De Graef
Lorentz transmission electron microscopy (TEM) observations of magnetic nanoparticles contain information on the magnetic and electrostatic potentials. Vector field electron tomography (VFET) can be used to reconstruct electromagnetic potentials of the nanoparticles from their corresponding LTEM images. The VFET approach is based on the conventional filtered back projection approach to tomographic reconstructions and the availability of an incomplete set of measurements due to experimental limitations means that the reconstructed vector fields exhibit significant artifacts...
July 3, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28683124/hybrid-spectral-ct-reconstruction
#11
Darin P Clark, Cristian T Badea
Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem...
2017: PloS One
https://www.readbyqxmd.com/read/28673448/renovascular-ct-comparison-between-adaptive-statistical-iterative-reconstruction-and-model-based-iterative-reconstruction
#12
Y Noda, S Goshima, H Koyasu, S Shigeyama, T Miyoshi, H Kawada, N Kawai, M Matsuo
AIM: To compare contrast enhancement and image quality between renovascular computed tomography (CT) images with adaptive statistical iterative reconstruction (ASiR) and that with model-based iterative reconstruction (MBIR). MATERIAL AND METHODS: This retrospective study was approved by the institutional review board and written informed consent was waived. Twenty-five consecutive patients who underwent renovascular CT were enrolled in this study. The same raw projection data were reconstructed using ASiR 40%, 100%, and MBIR...
June 30, 2017: Clinical Radiology
https://www.readbyqxmd.com/read/28669295/nerve-transfer-versus-muscle-transfer-to-restore-elbow-flexion-after-pan-brachial-plexus-injury-a-cost-effectiveness-analysis
#13
Arvin R Wali, David R Santiago-Dieppa, Justin M Brown, Ross Mandeville
OBJECTIVE Pan-brachial plexus injury (PBPI), involving C5-T1, disproportionately affects young males, causing lifelong disability and decreased quality of life. The restoration of elbow flexion remains a surgical priority for these patients. Within the first 6 months of injury, transfer of spinal accessory nerve (SAN) fascicles via a sural nerve graft or intercostal nerve (ICN) fascicles to the musculocutaneous nerve can restore elbow flexion. Beyond 1 year, free-functioning muscle transplantation (FFMT) of the gracilis muscle can be used to restore elbow flexion...
July 2017: Neurosurgical Focus
https://www.readbyqxmd.com/read/28668422/effects-of-pure-and-hybrid-iterative-reconstruction-algorithms-on-high-resolution-computed-tomography-in-the-evaluation-of-interstitial-lung-disease
#14
Masaki Katsura, Jiro Sato, Masaaki Akahane, Yoko Mise, Kaoru Sumida, Osamu Abe
OBJECTIVES: To compare image quality characteristics of high-resolution computed tomography (HRCT) in the evaluation of interstitial lung disease using three different reconstruction methods: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). METHODS: Eighty-nine consecutive patients with interstitial lung disease underwent standard-of-care chest CT with 64-row multi-detector CT...
August 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28667349/pediatric-320-row-cardiac-computed-tomography-using-electrocardiogram-gated-model-based-full-iterative-reconstruction
#15
Go Shirota, Eriko Maeda, Yoko Namiki, Razibul Bari, Kenji Ino, Rumiko Torigoe, Osamu Abe
BACKGROUND: Full iterative reconstruction algorithm is available, but its diagnostic quality in pediatric cardiac CT is unknown. OBJECTIVE: To compare the imaging quality of two algorithms, full and hybrid iterative reconstruction, in pediatric cardiac CT. MATERIALS AND METHODS: We included 49 children with congenital cardiac anomalies who underwent cardiac CT. We compared quality of images reconstructed using the two algorithms (full and hybrid iterative reconstruction) based on a 3-point scale for the delineation of the following anatomical structures: atrial septum, ventricular septum, right atrium, right ventricle, left atrium, left ventricle, main pulmonary artery, ascending aorta, aortic arch including the patent ductus arteriosus, descending aorta, right coronary artery and left main trunk...
June 30, 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28664415/validation-of-three-dimensional-models-of-the-distal-femur-created-from-surgical-navigation-point-cloud-data-for-intraoperative-and-postoperative-analysis-of-total-knee-arthroplasty
#16
David A J Wilson, Carolyn Anglin, Felix Ambellan, Carl Martin Grewe, Alexander Tack, Hans Lamecker, Michael Dunbar, Stefan Zachow
PURPOSE: Despite the success of total knee arthroplasty, there continues to be a significant proportion of patients who are dissatisfied. One explanation may be a shape mismatch between pre- and postoperative distal femurs. The purpose of this study was to investigate methods suitable for matching a statistical shape model (SSM) to intraoperatively acquired point cloud data from a surgical navigation system and to validate these against the preoperative magnetic resonance imaging (MRI) data from the same patients...
June 29, 2017: International Journal of Computer Assisted Radiology and Surgery
https://www.readbyqxmd.com/read/28660224/edge-artifacts-in-point-spread-function-based-pet-reconstruction-in-relation-to-object-size-and-reconstruction-parameters
#17
Yuji Tsutsui, Shinichi Awamoto, Kazuhiko Himuro, Yoshiyuki Umezu, Shingo Baba, Masayuki Sasaki
OBJECTIVES: We evaluated edge artifacts in relation to phantom diameter and reconstruction parameters in point spread function (PSF)-based positron emission tomography (PET) image reconstruction. METHODS: PET data were acquired from an original cone-shaped phantom filled with (18)F solution (21.9 kBq/mL) for 10 min using a Biograph mCT scanner. The images were reconstructed using the baseline ordered subsets expectation maximization (OSEM) algorithm and the OSEM with PSF correction model...
2017: Asia Oceania Journal of Nuclear Medicine & Biology
https://www.readbyqxmd.com/read/28657201/comparison-of-low-and-ultra-low-dose-computed-tomography-protocols-for-quantitative-lung-and-airway-assessment
#18
Emily Hammond, Chelsea Sloan, John D Newell, Jered P Sieren, Melissa Saylor, Craig Vidal, Shayna Hogue, Frank De Stefano, Alexa Sieren, Eric A Hoffman, Jessica C Sieren
PURPOSE: Quantitative computed tomography (CT) measures are increasingly being developed and used to characterize lung disease. With recent advances in CT technologies, we sought to evaluate the quantitative accuracy of lung imaging at low and ultra-low radiation doses with the use of iterative reconstruction (IR), tube current modulation (TCM), and spectral shaping. METHODS: We investigated the effect of five independent CT protocols reconstructed with IR on quantitative airway measures and global lung measures using an in-vivo large animal model as a human subject surrogate...
June 28, 2017: Medical Physics
https://www.readbyqxmd.com/read/28654572/quantifying-decreased-radiation-exposure-from-modern-ct-scan-technology-and-surveillance-programs-of-germ-cell-tumors
#19
Stephanie A Howard, Michael H Rosenthal, Lei Qin, Shanna A Matalon, Brandon D Bernard, Clair J Beard, Christopher J Sweeney
INTRODUCTION: Upgrading computerized tomography (CT) scanners to iterative reconstruction techniques (IRT) decreases radiation dose. This reduction, combined with changes in surveillance protocols in clinical stage I testicular cancer (CS1TC) measurably decrease the lifetime attributable risk (LAR) of dying of radiation-associated cancer. MATERIALS AND METHODS: This IRB-approved study enrolled 24 CS1TC patients who had CT scans on the same Toshiba Aquilion 64 CT before and after IRT software installation...
June 26, 2017: American Journal of Clinical Oncology
https://www.readbyqxmd.com/read/28650806/3d-active-contour-segmentation-based-on-sparse-linear-combination-of-training-shapes-scots
#20
M Mehdi Farhangi, Hichem Frigui, Albert Seow, Amir A Amini
SCoTS captures a sparse representation of shapes in an input image through a linear span of previously delineated shapes in a training repository. The model updates shape prior over level set iterations and captures variabilities in shapes by a sparse combination of the training data. The level set evolution is therefore driven by a data term as well as a term capturing valid prior shapes. During evolution, the shape prior influence is adjusted based on shape reconstruction, with the assigned weight determined from the degree of sparsity of the representation...
June 26, 2017: IEEE Transactions on Medical Imaging
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