Searched for: subject%3A%22Image%255C%2Breconstruction%22
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Bekkering, Aleid (author)
MRI has been used worldwide as an imaging modality for decades due to its ability to distinguish between soft tissues. However, MRIs cannot be used in all situations due to their extensive hard- and software. For this reason, research in the field of low-field MRI has been conducted. Low-field MRI systems do not use superconducting magnets but...
master thesis 2022
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Stölzle, Maximilian (author), Miki, Takahiro (author), Gerdes, Levin (author), Azkarate, Martin (author), Hutter, Marco (author)
Accurate and complete terrain maps enhance the awareness of autonomous robots and enable safe and optimal path planning. Rocks and topography often create occlusions and lead to missing elevation information in the Digital Elevation Map (DEM). Currently, these occluded areas are either fully avoided during motion planning or the missing...
journal article 2022
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Mozaffarzadeh, M. (author), Verschuur, D.J. (author), Verweij, M.D. (author), Daeichin, V. (author), de Jong, N. (author), Renaud, G.G.J. (author)
Transcranial ultrasound imaging (TUI) is a diagnostic modality with numerous applications, but unfortunately, it is hindered by phase aberration caused by the skull. In this article, we propose to reconstruct a transcranial B-mode image with a refraction-corrected synthetic aperture imaging (SAI) scheme. First, the compressional sound...
journal article 2022
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Izarin, Milan (author)
Recently, many advancements have been made in accelerated MRI reconstruction with the use of neural networks. Such deep learning methods learn a suitable MRI prior distribution from large sets of training data. For MRI images acquired with an uncommon scanning sequence, large datasets required for training are not available. Additionally, deep...
master thesis 2021
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van der Werff, Karen (author)
Magnetic Resonance Imaging (MRI) is a non-invasive, non-ionizing imaging modality that is commonly used in the clinic today. However, it is an expensive technique. The high purchase, operational and maintenance costs, as well as the need for trained staff with technical expertise, put this technique out of reach for a large part of the world...
master thesis 2021
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de Leeuw den Bouter, M.L. (author), van Gijzen, M.B. (author), Remis, R.F. (author)
In this paper we present a magnetic resonance imaging (MRI) technique that is based on multiplicative regularization. Instead of adding a regularizing objective function to a data fidelity term, we multiply by such a regularizing function. By following this approach, no regularization parameter needs to be determined for each new data set...
journal article 2021
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de Leeuw den Bouter, M.L. (author), van den Berg, P.M. (author), Remis, R.F. (author)
In this paper we discuss an imaging method when the object has known support and its spatial Fourier transform is only known on a certain k-space undersampled pattern. The simple conjugate gradient least squares algorithm applied to the corresponding truncated Fourier transform equation produces reconstructions that are basically of a similar...
journal article 2021
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Schaart, D.R. (author), Schramm, Georg (author), Nuyts, Johan (author), Surti, Suleman (author)
The first time-of-flight positron emission tomography (TOF-PET) scanners were developed as early as in the 1980s. However, the poor light output and low detection efficiency of TOF-capable detectors available at the time limited any gain in image quality achieved with these TOF-PET scanners over the traditional non-TOF PET scanners. The...
review 2021
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Ahishakiye, Emmanuel (author), van Gijzen, M.B. (author), Shan, X. (author), Tumwiine, Julius (author), Obungoloch, Johnes (author)
Currently, many children with hydrocephalus in East Africa and other resource-constrained countries do not have access to Magnetic Resonance Imaging (MRI) scanners, the preferred imaging tool during the disease administration and treatment. Conventional MRI scanners are costly to buy and manage, which limits their utilization in low-income...
conference paper 2021
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Koolstra, Kirsten (author), Remis, R.F. (author)
Purpose: To learn a preconditioner that accelerates parallel imaging (PI) and compressed sensing (CS) reconstructions. Methods: A convolutional neural network (CNN) with residual connections was used to train a preconditioning operator. Training and validation data were simulated using 50% brain images and 50% white Gaussian noise images....
journal article 2021
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López-Marín, Antonio (author), Springeling, Geert (author), Beurskens, Robert (author), Van Beusekom, Heleen (author), van der Steen, A.F.W. (author), Koch, Arjun D. (author), Bouma, Brett E. (author), Huber, Robert A. (author), Van Soest, Gijs (author), Wang, Tianshi (author)
In this study, we demonstrate a 12x36 mm motorized capsule for OCT imaging of the esophagus. The capsule produces unobstructed images by using a distal reflector design, thus avoiding shadow caused by the motor wires. The motor synchronous control enables three working modes: circumferential imaging, angular sector imaging and accurate beam...
conference paper 2020
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Pezzotti, Nicola (author), Yousefi, Sahar (author), Elmahdy, Mohamed S. (author), van Gemert, Jeroen Hendrikus Fransiscus (author), Schuelke, Christophe (author), Doneva, Mariya (author), Nielsen, Tim (author), Lelieveldt, B.P.F. (author), Staring, M. (author)
Adaptive intelligence aims at empowering machine learning techniques with the additional use of domain knowledge. In this work, we present the application of adaptive intelligence to accelerate MR acquisition. Starting from undersampled k-space data, an iterative learning-based reconstruction scheme inspired by compressed sensing theory is...
journal article 2020
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Ahishakiye, Emmanuel (author), van Gijzen, M.B. (author), Tumwiine, Julius (author), Obungoloch, Johnes (author)
Background: Magnetic resonance imaging (MRI) is a safe non-invasive and nonionizing medical imaging modality that is used to visualize the structure of human anatomy. Conventional (high-field) MRI scanners are very expensive to purchase, operate and maintain, which limit their use in many developing countries. This study is part of a project...
journal article 2020
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Ahishakiye, Emmanuel (author), van Gijzen, M.B. (author), Tumwiine, Julius (author), Obungoloch, Johnes (author)
Objective: Image denoising has been considered as a separate procedure from image reconstruction which could otherwise be combined with acquisition and reconstruction. This paper discusses a joint image reconstruction and denoising algorithm in low-field MRI using a dictionary learning approach. Method: Our proposed algorithm uses a two-level...
conference paper 2020
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Zhao, Wenzhao (author), Wang, Hongjian (author), Gemmeke, Hartmut (author), van Dongen, K.W.A. (author), Hopp, Torsten (author), Hesser, Jürgen (author)
Image reconstruction of ultrasound computed tomography based on the wave equation is able to show much more structural details than simpler ray-based image reconstruction methods. However, to invert the wave-based forward model is computationally demanding. To address this problem, we develop an efficient fully learned image reconstruction...
journal article 2020
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van Hoek, Bob (author)
Background: For both hospitals and patients it would be beneficial if the scan time of MR images could be reduced. At the moment, Compressed Sensing (CS) is introduced to reduce the scan time, however, new methods are developed such as a deep learning method, called the Recurrent Inference Machine (RIM). In this study the effect of...
master thesis 2019
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Saeedifar, M. (author), Mansvelder, Jasmijn (author), Mohammadi, R. (author), Zarouchas, D. (author)
This study aims to use the passive and active acoustic-based health monitoring methods for impact damage assessment of composite structures. To this aim, a Carbon Fiber Reinforced Polymer (CFRP) composite plate was fabricated and subjected to a simulated low-velocity impact by performing repeated quasi-static indentation tests where a loading...
journal article 2019
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Waling, Manon (author)
De CT-scanner heeft een belangrijke rol in de medische wereld. Helaas gebruikt de CT-scanner voor het opstellen van een scan schadelijke straling. In dit onderzoek is nagegaan of er een betere beeldreconstructietechniek te vinden is voor het opstellen van een CT-afbeelding met gebruik van minder straling.<br/>De standaard voor het opstellen van...
bachelor thesis 2019
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Guo, Y. (author), Rieger, B. (author)
Regularization has been introduced to electron tomography for enhancing the reconstruction quality. Since over-regularization smears out sharp edges and under-regularization leaves the image too noisy, finding the optimal regularization strength is crucial. To this end, one can either manually tune regularization parameters by trial and error...
conference paper 2019
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Sun, S. (author), Kooij, B.J. (author), Yarovoy, Alexander (author)
In this paper, the generalized multiple measurement vectors (GMMV) linear inversion method is applied to the reconstruction of the 3-D Fresnel data, provided by the Institue Fresnel (Marseille, France). The results show that the GMMV-based method can obtain good resolution along the x- and y- axes, while poor resolution along the z-axis,...
conference paper 2019
Searched for: subject%3A%22Image%255C%2Breconstruction%22
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