Multicontrast reconstruction using compressed sensing with low rank and spatially varying edge-preserving constraints for high-resolution MR characterization of myocardial infarction

2016 ◽  
Vol 78 (2) ◽  
pp. 598-610 ◽  
Author(s):  
Li Zhang ◽  
Prashant Athavale ◽  
Mihaela Pop ◽  
Graham A. Wright
Keyword(s):  
Myocardial Infarction ◽  
High Resolution ◽  
Compressed Sensing ◽  
Low Rank ◽  
Edge Preserving ◽  
Spatially Varying

scholarly journals Achieving High-Resolution Whole-Brain Slab 1H-MRSI with Compressed-Sensing and Low-Rank Reconstruction at 7 Tesla

2020 ◽  
Author(s):  
Antoine Klauser ◽  
Bernhard Strasser ◽  
Bijaya Thapa ◽  
Francois Lazeyras ◽  
Ovidiu Andronesi
Keyword(s):  
High Resolution ◽  
Compressed Sensing ◽  
Three Dimensions ◽  
Low Rank ◽  
7 Tesla ◽  
Brain Anatomy ◽  
Ultra High Field ◽  
Whole Brain ◽  
Low Sensitivity ◽  
Generalized Variation

Low sensitivity MR techniques such as magnetic resonance spectroscopic imaging (MRSI) greatly benefit from the gain in signal-to-noise (SNR) provided by ultra-high field MR. High-resolution and whole-brain slab MRSI remains however very challenging due to lengthy acquisition, low signal, lipid contamination and field inhomogeneity. In this study, we propose an acquisition-reconstruction scheme that combines a 1H-FID-MRSI sequence with compressed sensing acceleration and low-rank modeling with total-generalized-variation constraint to achieve metabolite imaging in two and three dimensions at 7 Tesla. The resulting images and volumes reveal highly detailed distributions that are specific to each metabolite and follow the underlying brain anatomy. The MRSI method was validated in a high-resolution phantom containing fine metabolite structures, and in 3 healthy volunteers. This new application of compressed sensing acceleration paves the way for high-resolution MRSI in clinical setting with acquisition times of 5 min for 2D MRSI at 2.5 mm and of 20 min for 3D MRSI at 3.3 mm isotropic.

scholarly journals High Resolution Imaging and Histopathological Characterization of Myocardial Infarction

2019 ◽  
Vol 116 (3) ◽  
pp. 231a ◽  
Author(s):  
Peter Lin ◽  
Jared Westreich ◽  
Mengyuan Li ◽  
Adam Gribble ◽  
Susan Newbigging ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
High Resolution ◽  
High Resolution Imaging ◽  
Resolution Imaging

scholarly journals Whole‐brain high‐resolution metabolite mapping with 3D compressed‐sensing SENSE low‐rank 1 H FID‐MRSI

2021 ◽  
Author(s):  
Antoine Klauser ◽  
Paul Klauser ◽  
Frédéric Grouiller ◽  
Sébastien Courvoisier ◽  
François Lazeyras
Keyword(s):  
High Resolution ◽  
Compressed Sensing ◽  
Low Rank ◽  
Whole Brain

scholarly journals Achieving High-Resolution 1H-MRSI of the Human Brain with Compressed-Sensing and Low-Rank Reconstruction at 7 Tesla.

2021 ◽  
pp. 107048
Author(s):  
Antoine Klauser ◽  
Bernhard Strasser ◽  
Bijaya Thapa ◽  
Francois Lazeyras ◽  
Ovidiu Andronesi
Keyword(s):  
High Resolution ◽  
Compressed Sensing ◽  
Human Brain ◽  
Low Rank ◽  
7 Tesla

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

High-resolution electron microscopy of nanostructured materials

1995 ◽  
Vol 53 ◽  
pp. 172-173
Author(s):  
M. José-Yacamán
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Nanostructured Materials ◽  
High Resolution Electron Microscopy ◽  
Hrem Image ◽  
Small Particles ◽  
Resolution Electron ◽  
Nanophase Materials

Electron microscopy is a fundamental tool in materials characterization. In the case of nanostructured materials we are looking for features with a size in the nanometer range. Therefore often the conventional TEM techniques are not enough for characterization of nanophases. High Resolution Electron Microscopy (HREM), is a key technique in order to characterize those materials with a resolution of ~ 1.7A. High resolution studies of metallic nanostructured materials has been also reported in the literature. It is concluded that boundaries in nanophase materials are similar in structure to the regular grain boundaries. That work therefore did not confirm the early hipothesis on the field that grain boundaries in nanostructured materials have a special behavior. We will show in this paper that by a combination of HREM image processing, and image calculations, it is possible to prove that small particles and coalesced grains have a significant surface roughness, as well as large internal strain.

High-resolution transmission electron microscopic study of highly oxygen doped silicon layer

1989 ◽  
Vol 47 ◽  
pp. 692-693
Author(s):  
H. Takaoka ◽  
M. Tomita ◽  
T. Hayashi
Keyword(s):  
High Resolution ◽  
Oxygen Concentration ◽  
Silicon Layer ◽  
Detailed Structure ◽  
Electron Microscopic ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Doped Silicon ◽  
Argon Ion

High resolution transmission electron microscopy (HRTEM) is the effective technique for characterization of detailed structure of semiconductor materials. Oxygen is one of the important impurities in semiconductors. Detailed structure of highly oxygen doped silicon has not clearly investigated yet. This report describes detailed structure of highly oxygen doped silicon observed by HRTEM. Both samples prepared by Molecular beam epitaxy (MBE) and ion implantation were observed to investigate effects of oxygen concentration and doping methods to the crystal structure.The observed oxygen doped samples were prepared by MBE method in oxygen environment on (111) substrates. Oxygen concentration was about 1021 atoms/cm3. Another sample was silicon of (100) orientation implanted with oxygen ions at an energy of 180 keV. Oxygen concentration of this sample was about 1020 atoms/cm3 Cross-sectional specimens of (011) orientation were prepared by argon ion thinning and were observed by TEM at an accelerating voltage of 400 kV.

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