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magnetic resonance fingerprinting

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https://www.readbyqxmd.com/read/28804918/low-rank-approximation-methods-for-mr-fingerprinting-with-large-scale-dictionaries
#1
Mingrui Yang, Dan Ma, Yun Jiang, Jesse Hamilton, Nicole Seiberlich, Mark A Griswold, Debra McGivney
PURPOSE: This work proposes new low rank approximation approaches with significant memory savings for large scale MR fingerprinting (MRF) problems. THEORY AND METHODS: We introduce a compressed MRF with randomized singular value decomposition method to significantly reduce the memory requirement for calculating a low rank approximation of large sized MRF dictionaries. We further relax this requirement by exploiting the structures of MRF dictionaries in the randomized singular value decomposition space and fitting them to low-degree polynomials to generate high resolution MRF parameter maps...
August 13, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28796368/regularly-incremented-phase-encoding-mr-fingerprinting-ripe-mrf-for-enhanced-motion-artifact-suppression-in-preclinical-cartesian-mr-fingerprinting
#2
Christian E Anderson, Charlie Y Wang, Yuning Gu, Rebecca Darrah, Mark A Griswold, Xin Yu, Chris A Flask
PURPOSE: The regularly incremented phase encoding-magnetic resonance fingerprinting (RIPE-MRF) method is introduced to limit the sensitivity of preclinical MRF assessments to pulsatile and respiratory motion artifacts. METHODS: As compared to previously reported standard Cartesian-MRF methods (SC-MRF), the proposed RIPE-MRF method uses a modified Cartesian trajectory that varies the acquired phase-encoding line within each dynamic MRF dataset. Phantoms and mice were scanned without gating or triggering on a 7T preclinical MRI scanner using the RIPE-MRF and SC-MRF methods...
August 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28776774/identification-of-some-bioactive-metabolites-in-a-fractionated-methanol-extract-from-ipomoea-aquatica-aerial-parts-through-tlc-hplc-uplc-esi-qtof-ms-and-lc-spe-nmr-fingerprints-analyses
#3
Mahmoud Hefny Gad, Emmy Tuenter, Nagwa El-Sawi, Sabry Younes, El-Mewafy El-Ghadban, Kristiaan Demeyer, Luc Pieters, Yvan Vander Heyden, Debby Mangelings
INTRODUCTION: The plant species Ipomoea aquatica contains various bioactive constituents, e.g. phenols and flavonoids, which have several medical uses. All previous studies were executed in Asia; however, no reports are available from Africa, and the secondary metabolites of this plant species from Africa are still unknown. OBJECTIVE: The present study aims finding suitable conditions to identify the bioactive compounds from different fractions. METHODOLOGY: Chromatographic fingerprint profiles of different fractions were developed using high-performance liquid chromatography (HPLC) and then these conditions were transferred to thin-layer chromatography (TLC)...
August 4, 2017: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28769889/fast-2d-nmr-spectroscopy-for-in-vivo-monitoring-of-bacterial-metabolism-in-complex-mixtures
#4
Rupashree Dass, Katarzyna Grudzia Ż, Takao Ishikawa, Michał Nowakowski, Renata Dȩbowska, Krzysztof Kazimierczuk
The biological toolbox is full of techniques developed originally for analytical chemistry. Among them, spectroscopic experiments are very important source of atomic-level structural information. Nuclear magnetic resonance (NMR) spectroscopy, although very advanced in chemical and biophysical applications, has been used in microbiology only in a limited manner. So far, mostly one-dimensional (1)H experiments have been reported in studies of bacterial metabolism monitored in situ. However, low spectral resolution and limited information on molecular topology limits the usability of these methods...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28743861/multimodal-fingerprints-of-resting-state-networks-as-assessed-by-simultaneous-trimodal-mr-pet-eeg-imaging
#5
N J Shah, J Arrubla, R Rajkumar, E Farrher, J Mauler, E Rota Kops, L Tellmann, J Scheins, F Boers, J Dammers, P Sripad, C Lerche, K J Langen, H Herzog, I Neuner
Simultaneous MR-PET-EEG (magnetic resonance imaging - positron emission tomography - electroencephalography), a new tool for the investigation of neuronal networks in the human brain, is presented here for the first time. It enables the assessment of molecular metabolic information with high spatial and temporal resolution in a given brain simultaneously. Here, we characterize the brain's default mode network (DMN) in healthy male subjects using multimodal fingerprinting by quantifying energy metabolism via 2- [(18)F]fluoro-2-desoxy-D-glucose PET (FDG-PET), the inhibition - excitation balance of neuronal activation via magnetic resonance spectroscopy (MRS), its functional connectivity via fMRI and its electrophysiological signature via EEG...
July 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28716682/air-mrf-accelerated-iterative-reconstruction-for-magnetic-resonance-fingerprinting
#6
Christopher C Cline, Xiao Chen, Boris Mailhe, Qiu Wang, Josef Pfeuffer, Mathias Nittka, Mark A Griswold, Peter Speier, Mariappan S Nadar
Existing approaches for reconstruction of multiparametric maps with magnetic resonance fingerprinting (MRF) are currently limited by their estimation accuracy and reconstruction time. We aimed to address these issues with a novel combination of iterative reconstruction, fingerprint compression, additional regularization, and accelerated dictionary search methods. The pipeline described here, accelerated iterative reconstruction for magnetic resonance fingerprinting (AIR-MRF), was evaluated with simulations as well as phantom and in vivo scans...
July 14, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28694017/multi-frequency-interpolation-in-spiral-magnetic-resonance-fingerprinting-for-correction-of-off-resonance-blurring
#7
Jason Ostenson, Ryan K Robison, Nicholas R Zwart, E Brian Welch
Magnetic resonance fingerprinting (MRF) pulse sequences often employ spiral trajectories for data readout. Spiral k-space acquisitions are vulnerable to blurring in the spatial domain in the presence of static field off-resonance. This work describes a blurring correction algorithm for use in spiral MRF and demonstrates its effectiveness in phantom and in vivo experiments. Results show that image quality of T1 and T2 parametric maps is improved by application of this correction. This MRF correction has negligible effect on the concordance correlation coefficient and improves coefficient of variation in regions of off-resonance relative to uncorrected measurements...
July 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28684331/fiberprint-a-subject-fingerprint-based-on-sparse-code-pooling-for-white-matter-fiber-analysis
#8
Kuldeep Kumar, Christian Desrosiers, Kaleem Siddiqi, Olivier Colliot, Matthew Toews
White matter characterization studies use the information provided by diffusion magnetic resonance imaging (dMRI) to draw cross-population inferences. However, the structure, function, and white matter geometry vary across individuals. Here, we propose a subject fingerprint, called Fiberprint, to quantify the individual uniqueness in white matter geometry using fiber trajectories. We learn a sparse coding representation for fiber trajectories by mapping them to a common space defined by a dictionary. A subject fingerprint is then generated by applying a pooling function for each bundle, thus providing a vector of bundle-wise features describing a particular subject's white matter geometry...
July 3, 2017: NeuroImage
https://www.readbyqxmd.com/read/28684268/towards-predicting-the-encoding-capability-of-mr-fingerprinting-sequences
#9
K Sommer, T Amthor, M Doneva, P Koken, J Meineke, P Börnert
Sequence optimization and appropriate sequence selection is still an unmet need in magnetic resonance fingerprinting (MRF). The main challenge in MRF sequence design is the lack of an appropriate measure of the sequence's encoding capability. To find such a measure, three different candidates for judging the encoding capability have been investigated: local and global dot-product-based measures judging dictionary entry similarity as well as a Monte Carlo method that evaluates the noise propagation properties of an MRF sequence...
July 3, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28666939/magnetic-resonance-fingerprinting-with-short-relaxation-intervals
#10
Thomas Amthor, Mariya Doneva, Peter Koken, Karsten Sommer, Jakob Meineke, Peter Börnert
PURPOSE: To investigate a technique for improving the performance of Magnetic Resonance Fingerprinting (MRF) in repetitive sampling schemes, especially suited for 3D MRF acquisition, by shortening relaxation intervals between MRF pulse train repetitions. MATERIAL AND METHODS: A calculation method for MRF dictionaries adapted to short relaxation intervals and non-relaxed initial spin states is presented, based on the concept of stationary fingerprints. The method is applicable to many different k-space sampling schemes in 2D and 3D...
June 27, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28666880/connectopic-mapping-with-resting-state-fmri
#11
REVIEW
Koen V Haak, Andre F Marquand, Christian F Beckmann
Brain regions are often topographically connected: nearby locations within one brain area connect with nearby locations in another area. Mapping these connection topographies, or 'connectopies' in short, is crucial for understanding how information is processed in the brain. Here, we propose principled, fully data-driven methods for mapping connectopies using functional magnetic resonance imaging (fMRI) data acquired at rest by combining spectral embedding of voxel-wise connectivity 'fingerprints' with a novel approach to spatial statistical inference...
June 27, 2017: NeuroImage
https://www.readbyqxmd.com/read/28662085/metabolomic-profiling-to-characterize-acute-intestinal-ischemia-reperfusion-injury
#12
Rachel G Khadaroo, Thomas A Churchill, Victor Tso, Karen L Madsen, Chris Lukowski, Saad Y Salim
Sepsis and septic shock are the leading causes of death in critically ill patients. Acute intestinal ischemia/reperfusion (AII/R) is an adaptive response to shock. The high mortality rate from AII/R is due to the severity of the disease and, more importantly, the failure of timely diagnosis. The objective of this investigation is to use nuclear magnetic resonance (NMR) analysis to characterize urine metabolomic profile of AII/R injury in a mouse model. Animals were exposed to sham, early (30 min) or late (60 min) acute intestinal ischemia by complete occlusion of the superior mesenteric artery, followed by 2 hrs of reperfusion...
2017: PloS One
https://www.readbyqxmd.com/read/28583765/current-role-and-future-perspectives-of-multivariate-chemometric-methods-in-nmr-spectroscopic-analysis-of-pharmaceutical-products
#13
REVIEW
Yulia B Monakhova, Ulrike Holzgrabe, Bernd W K Diehl
Nuclear magnetic resonance (NMR) is a fast and accurate analytical method. Associated with chemometrics, it gradually becomes more important tool for the pharmaceutical industry. In this review studies dealing with the applications of multivariate analysis to NMR spectroscopic profiles were grouped and discussed according to the analytical problem solved. The following topics were covered: authenticity of medicines according to variety, seasonal and geographical differences of herbal plants; quantitative prediction of pharmacologically relevant parameters; production and batches approval; investigation of drug structure modifications; site-specific natural isotope fractionation (SNIF-NMR) fingerprinting for origin and manufacturer tracking and others...
May 27, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28553201/fe65-ptb2-dimerization-mimics-fe65-app-interaction
#14
Lukas P Feilen, Kevin Haubrich, Paul Strecker, Sabine Probst, Simone Eggert, Gunter Stier, Irmgard Sinning, Uwe Konietzko, Stefan Kins, Bernd Simon, Klemens Wild
Physiological function and pathology of the Alzheimer's disease causing amyloid precursor protein (APP) are correlated with its cytosolic adaptor Fe65 encompassing a WW and two phosphotyrosine-binding domains (PTBs). The C-terminal Fe65-PTB2 binds a large portion of the APP intracellular domain (AICD) including the GYENPTY internalization sequence fingerprint. AICD binding to Fe65-PTB2 opens an intra-molecular interaction causing a structural change and altering Fe65 activity. Here we show that in the absence of the AICD, Fe65-PTB2 forms a homodimer in solution and determine its crystal structure at 2...
2017: Frontiers in Molecular Neuroscience
https://www.readbyqxmd.com/read/28544938/sex-steroids-and-metabolic-responses-in-mussels-mytilus-galloprovincialis-exposed-to-drospirenone
#15
Tiziana Cappello, Denise Fernandes, Maria Maisano, Andrea Casano, Marta Bonastre, Maria João Bebianno, Angela Mauceri, Salvatore Fasulo, Cinta Porte
Drospirenone (DRO) is a synthetic progestin derived from 17α-spironolactone with a pharmacological mechanism of action similar to progesterone. Despite its wide use as pharmaceutical and consequent continuous release into the aquatic environment, DRO effects have been poorly investigated on aquatic biota. In order to unravel the toxicity mechanisms of DRO, mussels Mytilus galloprovincialis were exposed for 7 days to different concentrations of DRO, namely 20ng/L (Low; L), 200ng/L (Medium; M), 2000ng/L (High; H) and 10μg/L (Super High; SH) nominal doses...
May 22, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28542375/human-plasma-metabolomics-in-age-related-macular-degeneration-amd-using-nuclear-magnetic-resonance-spectroscopy
#16
Inês Laíns, Daniela Duarte, António S Barros, Ana Sofia Martins, João Gil, John B Miller, Marco Marques, Tânia Mesquita, Ivana K Kim, Maria da Luz Cachulo, Demetrios Vavvas, Isabel M Carreira, Joaquim N Murta, Rufino Silva, Joan W Miller, Deeba Husain, Ana M Gil
PURPOSE: To differentiate the plasma metabolomic profile of patients with age related macular degeneration (AMD) from that of controls, by Nuclear Magnetic Resonance (NMR) spectroscopy. METHODS: Two cohorts (total of 396 subjects) representative of central Portugal and Boston, USA phenotypes were studied. For each cohort, subjects were grouped according to AMD stage (early, intermediate and late). Multivariate analysis of plasma NMR spectra was performed, followed by signal integration and univariate analysis...
2017: PloS One
https://www.readbyqxmd.com/read/28454057/application-of-2d-nmr-with-room-temperature-nmr-probes-for-the-assessment-of-the-higher-order-structure-of-filgrastim
#17
Robert G Brinson, Houman Ghasriani, Derek J Hodgson, Kristie M Adams, Ian McEwen, Darón I Freedberg, Kang Chen, David A Keire, Yves Aubin, John P Marino
The higher order structure (HOS) of biotherapeutics is a critical quality attribute that can be evaluated by nuclear magnetic resonance (NMR) spectroscopy at atomic resolution. NMR spectral mapping of HOS can be used to establish HOS consistency of a biologic across manufacturing changes or to compare a biosimilar to an innovator reference product. A previous inter-laboratory study performed using filgrastim drug products demonstrated that two-dimensional (2D)-NMR (1)H(N)-(15)N(H) heteronuclear correlation spectroscopy is a highly robust and precise method for mapping the HOS of biologic drugs at natural abundance using high sensitivity NMR 'cold probes...
April 4, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28450006/metabolic-profiles-from-two-different-breakfast-meals-characterized-by-1-h-nmr-based-metabolomics
#18
Millie Rådjursöga, Göran B Karlsson, Helen M Lindqvist, Anders Pedersen, Cecilia Persson, Rui Climaco Pinto, Lars Ellegård, Anna Winkvist
It is challenging to measure dietary exposure with techniques that are both accurate and applicable to free-living individuals. We performed a cross-over intervention, with 24 healthy individuals, to capture the acute metabolic response of a cereal breakfast (CB) and an egg and ham breakfast (EHB). Fasting and postprandial urine samples were analyzed using (1)H nuclear magnetic resonance (NMR) spectroscopy and multivariate data analysis. Metabolic profiles were distinguished in relation to ingestion of either CB or EHB...
September 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28433503/mr-fingerprinting-reconstruction-with-kalman-filter
#19
Xiaodi Zhang, Zechen Zhou, Shiyang Chen, Shuo Chen, Rui Li, Xiaoping Hu
Magnetic resonance fingerprinting (MR fingerprinting or MRF) is a newly introduced quantitative magnetic resonance imaging technique, which enables simultaneous multi-parameter mapping in a single acquisition with improved time efficiency. The current MRF reconstruction method is based on dictionary matching, which may be limited by the discrete and finite nature of the dictionary and the computational cost associated with dictionary construction, storage and matching. In this paper, we describe a reconstruction method based on Kalman filter for MRF, which avoids the use of dictionary to obtain continuous MR parameter measurements...
April 19, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28431306/difference-optimization-automatic-correction-of-relative-frequency-and-phase-for-mean-non-edited-and-edited-gaba-1-h-mega-press-spectra
#20
Marianne Cleve, Martin Krämer, Alexander Gussew, Jürgen R Reichenbach
Phase and frequency corrections of magnetic resonance spectroscopic data are of major importance to obtain reliable and unambiguous metabolite estimates as validated in recent research for single-shot scans with the same spectral fingerprint. However, when using the J-difference editing technique (1)H MEGA-PRESS, misalignment between mean edited (ON‾) and non-edited (OFF‾) spectra that may remain even after correction of the corresponding individual single-shot scans results in subtraction artefacts compromising reliable GABA quantitation...
April 7, 2017: Journal of Magnetic Resonance
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