Global ETD Search

1	Dynamic Temperature Mapping - Real-time Strategies and Model-based Reconstructions Zhang, Zhongshuai 14 December 2016 (has links) No description available. 571.4 MR thermometry real-time MRI nonlinear reconstruction model-based reconstruction laser induced thermal therapy Biologie (PPN619462639)
2	Development of Advanced Acquisition and Reconstruction Techniques for Real-Time Perfusion MRI Roeloffs, Volkert Brar 16 June 2016 (has links) Diese Doktorarbeit befasst sich mit der methodischen Entwicklung von Akquisition- und Rekonstruktionstechniken zur Anwendung von Echtzeit-Bildgebungstechniken auf das Gebiet der dynamischen kontrastmittelgestützten Magentresonanztomographie. Zur Unterdrückung unerwünschter Bildartefakte wird eine neue Spoiling-Technik vorgeschlagen, die auf randomisierten Phasen der Hochfrequenzanregung basiert. Diese Technik erlaubt eine schnelle, artefaktfreie Aufnahme von T1-gewichteten Rohdaten bei radialer Abtastung. Die Rekonstruktion quantitativer Parameterkarten aus solchen Rohdaten kann als nichtlineares, inverses Problem aufgefasst werden. In dieser Arbeit wird eine modellbasierte Rekonstruktionstechnik zur quantitativen T1-Kartierung entwickelt, die dieses inverse Problem mittels der iterativ regularisierten Gauß-Newton-Methode mit parameterspezifischer Regularisierung löst. In Simulationen sowie in-vitro- und in-vivo-Studien wird Genauigkeit und Präzision dieser neuen Methode geprüft, die ihre direkte Anwendung in in-vitro-Experimenten zur "first-pass"-Perfusion findet. In diesen Experimenten wird ein kommerziell verfügbares Phantom verwendet, dass in-vivo-Perfusion simuliert und gleichzeitig vollständige Kontrolle über die vorherrschenden Austauschraten erlaubt. 571.4 real-time MRI radial MRI model-based reconstruction T1 mapping T1 relaxometry spoiling Golden Angle DCE perfusion Biologie (PPN619462639)
3	Real-time MRI and Model-based Reconstruction Techniques for Parameter Mapping of Spin-lattice Relaxation Wang, Xiaoqing 18 October 2016 (has links) No description available. 530 Physik (PPN621336750) single-shot T1 mapping real-time MRI model-based reconstruction sparsity constraints Look-Locker inversion recovery radial FLASH myocardial T1 mapping parallel imaging GPU
4	Advances in real-time phase-contrast flow MRI and multi-echo radial FLASH Tan, Zhengguo 26 April 2016 (has links) No description available. 571.4 nonlinear inverse reconstruction radial MRI real-time MRI asymmetric echo phase-contrast flow MRI cardiovascular blood flow model-based reconstruction multi-echo T2* mapping off-resonance frequency mapping water-fat separation Biologie (PPN619462639)
5	RECONSTRUCTION OF HIGH-SPEED EVENT-BASED VIDEO USING PLUG AND PLAY Trevor D. Moore (5930756) 16 January 2019 (has links) <div>Event-Based cameras, also known as neuromophic cameras or dynamic vision sensors, are an imaging modality that attempt to mimic human eyes by asynchronously measuring contrast over time. If the contrast changes sufficiently then a 1-bit event is output, indicating whether the contrast has gone up or down. This stream of events is sparse, and its asynchronous nature allows the pixels to have a high dynamic range and high temporal resolution. However, these events do not encode the intensity of the scene, resulting in an inverse problem to estimate intensity images from the event stream. Hybrid event-based cameras, such as the DAVIS camera, provide a reference intensity image that can be leveraged when estimating the intensity at each pixel during an event. Normally, inverse problems are solved by formulating a forward and prior model and minimizing the associated cost, however, for this problem, the Plug and Play (P&P) algorithm is used to solve the inverse problem. In this case, P&P replaces the prior model subproblem with a denoiser, making the algorithm modular, easier to implement. We propose an idealized forward model that assumes the contrast steps measured by the DAVIS camera are uniform in size to simplify the problem. We show that the algorithm can swiftly reconstruct the scene intensity at a user-specified frame rate, depending on the chosen denoiser’s computational complexity and the selected frame rate.</div> Image Processing image processing image reconstruction high-speed imaging neuromorphic vision sensor event-based vision plug and play High Dynamic Range Imaging Computational Imaging model-based reconstruction
6	Multi-Directional Phase-Contrast Flow MRI in Real Time Kollmeier, Jost M. 31 August 2020 (has links) No description available. 571.4 real-time MRI phase-contrast MRI radial MRI model-based reconstruction radial Maxwell correction multi-directional flow 4D flow velocimetry Karman vortex shedding blood flow CSF flow 3D flow Biologie (PPN619462639)
7	Mitigating atmospheric phase errors in SAL data Depoy, Randy S., Jr. January 2020 (has links) No description available. Electrical Engineering Remote Sensing synthetic aperture ladar synthetic aperture lidar autofocus SAL model-based reconstruction sparse image formation sparse image reconstruction model error correction atmospheric phase error phase error spatially-variant phase error
8	Vision Beyond Optics: Standardization, Evaluation and Innovation for Fluorescence Microscopy in Life Sciences Huisman, Maximiliaan 01 April 2019 (has links) Fluorescence microscopy is an essential tool in biomedical sciences that allows specific molecules to be visualized in the complex and crowded environment of cells. The continuous introduction of new imaging techniques makes microscopes more powerful and versatile, but there is more than meets the eye. In addition to develop- ing new methods, we can work towards getting the most out of existing data and technologies. By harnessing unused potential, this work aims to increase the richness, reliability, and power of fluorescence microscopy data in three key ways: through standardization, evaluation and innovation. A universal standard makes it easier to assess, compare and analyze imaging data – from the level of a single laboratory to the broader life sciences community. We propose a data-standard for fluorescence microscopy that can increase the confidence in experimental results, facilitate the exchange of data, and maximize compatibility with current and future data analysis techniques. Cutting-edge imaging technologies often rely on sophisticated hardware and multi-layered algorithms for reconstruction and analysis. Consequently, the trustworthiness of new methods can be difficult to assess. To evaluate the reliability and limitations of complex methods, quantitative analyses – such as the one present here for the 3D SPEED method – are paramount. The limited resolution of optical microscopes prevents direct observation of macro- molecules like DNA and RNA. We present a multi-color, achromatic, cryogenic fluorescence microscope that has the potential to produce multi-color images with sub-nanometer precision. This innovation would move fluorescence imaging beyond the limitations of optics and into the world of molecular resolution. microscopy nanoscopy fluorescence cryogenic cryo-fluorescence cryoFM FM 3DSPEED SPEED standardization PSF PSF engineering achromatic dichroic multi-color super-resolution imaging imaging standard optics adaptive optics meta-data meta MetaMax calibration characterization back-projection image reconstruction pseudo-tomography model-based reconstruction chromatic aberrations cryogenic imaging 4D-PSF calibration tool Bioimaging and Biomedical Optics Biological Engineering Biomedical Devices and Instrumentation Biophysics Computer-Aided Engineering and Design Electrical and Electronics Electromagnetics and Photonics Electro-Mechanical Systems Engineering Physics Molecular Biology Nanoscience and Nanotechnology Numerical Analysis and Computation Optics Other Engineering Systems and Integrative Engineering

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