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Quantitative susceptibility mapping

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https://www.readbyqxmd.com/read/28324122/mr-imaging-differentiation-of-fe-2-and-fe-3-based-on-relaxation-and-magnetic-susceptibility-properties
#1
Olaf Dietrich, Johannes Levin, Seyed-Ahmad Ahmadi, Annika Plate, Maximilian F Reiser, Kai Bötzel, Armin Giese, Birgit Ertl-Wagner
PURPOSE: The aim of this study is to evaluate the MR imaging behavior of ferrous (Fe(2+)) and ferric (Fe(3+)) iron ions in order to develop a noninvasive technique to quantitatively differentiate between both forms of iron. METHODS: MRI was performed at 3 T in a phantom consisting of 21 samples with different concentrations of ferrous and ferric chloride solutions (between 0 and 10 mmol/L). A multi-echo spoiled gradient-echo pulse sequence with eight echoes was used for both T 2* and quantitative susceptibility measurements...
March 21, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28317125/referenceless-magnetic-resonance-temperature-imaging-using-gaussian-process-modeling
#2
Joshua P Yung, David Fuentes, Christopher J MacLellan, Florian Maier, Yannis Liapis, John D Hazle, R Jason Stafford
PURPOSE: During magnetic resonance (MR)-guided thermal therapies, water proton resonance frequency shift (PRFS) based MR temperature imaging can quantitatively monitor tissue temperature changes. It is widely known that the PRFS technique is easily perturbed by tissue motion, tissue susceptibility changes, magnetic field drift, and modality-dependent applicator induced artifacts. Here a referenceless Gaussian process modeling (GPM) based estimation of the PRFS is investigated as a methodology to mitigate unwanted background field changes...
March 20, 2017: Medical Physics
https://www.readbyqxmd.com/read/28303663/editorial-for-special-issue-on-mri-phase-contrast-and-quantitative-susceptibility-mapping
#3
EDITORIAL
Chunlei Liu, Richard Bowtell, John Schenck
No abstract text is available yet for this article.
April 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28301067/progressive-iron-accumulation-across-multiple-sclerosis-phenotypes-revealed-by-sparse-classification-of-deep-gray-matter
#4
Ahmed M Elkady, Dana Cobzas, Hongfu Sun, Gregg Blevins, Alan H Wilman
PURPOSE: To create an automated framework for localized analysis of deep gray matter (DGM) iron accumulation and demyelination using sparse classification by combining quantitative susceptibility (QS) and transverse relaxation rate (R2*) maps, for evaluation of DGM in multiple sclerosis (MS) phenotypes relative to healthy controls. MATERIALS AND METHODS: R2*/QS maps were computed using a 4.7T 10-echo gradient echo acquisition from 16 clinically isolated syndrome (CIS), 41 relapsing-remitting (RR), 40 secondary-progressive (SP), 13 primary-progressive (PP) MS patients, and 75 controls...
March 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28295954/clinical-quantitative-susceptibility-mapping-qsm-biometal-imaging-and-its-emerging-roles-in-patient-care
#5
REVIEW
Yi Wang, Pascal Spincemaille, Zhe Liu, Alexey Dimov, Kofi Deh, Jianqi Li, Yan Zhang, Yihao Yao, Kelly M Gillen, Alan H Wilman, Ajay Gupta, Apostolos John Tsiouris, Ilhami Kovanlikaya, Gloria Chia-Yi Chiang, Jonathan W Weinsaft, Lawrence Tanenbaum, Weiwei Chen, Wenzhen Zhu, Shixin Chang, Min Lou, Brian H Kopell, Michael G Kaplitt, David Devos, Toshinori Hirai, Xuemei Huang, Yukunori Korogi, Alexander Shtilbans, Geon-Ho Jahng, Daniel Pelletier, Susan A Gauthier, David Pitt, Ashley I Bush, Gary M Brittenham, Martin R Prince
Quantitative susceptibility mapping (QSM) has enabled magnetic resonance imaging (MRI) of tissue magnetic susceptibility to advance from simple qualitative detection of hypointense blooming artifacts to precise quantitative measurement of spatial biodistributions. QSM technology may be regarded to be sufficiently developed and validated to warrant wide dissemination for clinical applications of imaging isotropic susceptibility, which is dominated by metals in tissue, including iron and calcium. These biometals are highly regulated as vital participants in normal cellular biochemistry, and their dysregulations are manifested in a variety of pathologic processes...
March 10, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28295523/quantitative-susceptibility-mapping-based-cerebral-metabolic-rate-of-oxygen-mapping-with-minimum-local-variance
#6
Jingwei Zhang, Junghun Cho, Dong Zhou, Thanh D Nguyen, Pascal Spincemaille, Ajay Gupta, Yi Wang
PURPOSE: The objective of this study was to demonstrate the feasibility of a cerebral metabolic rate of oxygen (CMRO2 ) mapping method based on its minimum local variance (MLV) without vascular challenge using quantitative susceptibility mapping (QSM) and cerebral blood flow (CBF). METHODS: Three-dimensional multi-echo gradient echo imaging and arterial spin labeling were performed in 11 healthy subjects to calculate QSM and CBF. Minimum local variance was used to compute whole-brain CMRO2 map from QSM and CBF...
March 10, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28293708/inverse-gene-for-gene-interactions-contribute-additively-to-tan-spot-susceptibility-in-wheat
#7
Zhaohui Liu, Jason D Zurn, Gayan Kariyawasam, Justin D Faris, Gongjun Shi, Jana Hansen, Jack B Rasmussen, Maricelis Acevedo
Tan spot susceptibility is conferred by multiple interactions of necrotrophic effector and host sensitivity genes. Tan spot of wheat, caused by Pyrenophora tritici-repentis, is an important disease in almost all wheat-growing areas of the world. The disease system is known to involve at least three fungal-produced necrotrophic effectors (NEs) that interact with the corresponding host sensitivity (S) genes in an inverse gene-for-gene manner to induce disease. However, it is unknown if the effects of these NE-S gene interactions contribute additively to the development of tan spot...
March 14, 2017: TAG. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik
https://www.readbyqxmd.com/read/28289372/improved-quantification-of-cerebral-vein-oxygenation-using-partial-volume-correction
#8
Phillip G D Ward, Audrey P Fan, Parnesh Raniga, David G Barnes, David L Dowe, Amanda C L Ng, Gary F Egan
Purpose: Quantitative susceptibility mapping (QSM) enables cerebral venous characterization and physiological measurements, such as oxygen extraction fraction (OEF). The exquisite sensitivity of QSM to deoxygenated blood makes it possible to image small veins; however partial volume effects must be addressed for accurate quantification. We present a new method, Iterative Cylindrical Fitting (ICF), to estimate voxel-based partial volume effects for susceptibility maps and use it to improve OEF quantification of small veins with diameters between 1...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28286515/genetic-architecture-of-resistance-to-alternaria-brassicae-in-arabidopsis-thaliana-qtl-mapping-reveals-two-major-resistance-conferring-loci
#9
Sivasubramanian Rajarammohan, Amarendra Kumar, Vibha Gupta, Deepak Pental, Akshay K Pradhan, Jagreet Kaur
Alternaria brassicae, a necrotrophic fungal pathogen, causes Alternaria blight, one of the most important diseases of oleiferous Brassica crops. The current study utilized Arabidopsis as a model to decipher the genetic architecture of defense against A. brassicae. Significant phenotypic variation that was largely genetically determined was observed among Arabidopsis accessions in response to pathogen challenge. Three biparental mapping populations were developed from three resistant accessions viz. CIBC-5, Ei-2, and Cvi-0 and two susceptible accessions - Gre-0 and Zdr-1 (commonly crossed to CIBC-5 and Ei-2)...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28282586/mapping-axonal-density-and-average-diameter-using-non-monotonic-time-dependent-gradient-echo-mri
#10
Daniel Nunes, Tomás L Cruz, Sune N Jespersen, Noam Shemesh
White Matter (WM) microstructures, such as axonal density and average diameter, are crucial to the normal function of the Central Nervous System (CNS) as they are closely related with axonal conduction velocities. Conversely, disruptions of these microstructural features may result in severe neurological deficits, suggesting that their noninvasive mapping could be an important step towards diagnosing and following pathophysiology. Whereas diffusion based MRI methods have been proposed to map these features, they typically entail the application of powerful gradients, which are rarely available in the clinic, or extremely long acquisition schemes to extract information from parameter-intensive models...
February 28, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28273720/recurrence-of-glioblastoma-is-associated-with-elevated-microvascular-transit-time-heterogeneity-and-increased-hypoxia
#11
Andreas Stadlbauer, Kim Mouridsen, Arnd Doerfler, Mikkel Bo Hansen, Stefan Oberndorfer, Max Zimmermann, Michael Buchfelder, Gertraud Heinz, Karl Roessler
Dynamic susceptibility contrast (DSC) perfusion MRI provide information about differences in macro- and microvasculature when executed with gradient-echo (GE; sensitive to macrovasculature) and spin-echo (SE; sensitive to microvasculature) contrast. This study investigated whether there are differences between macro- and microvascular transit time heterogeneity (MVTH and µVTH) and tissue oxygen tension (PO2mit) in newly-diagnosed and recurrent glioblastoma. Fifty-seven patients with glioblastoma (25 newly-diagnosed/32 recurrent) were examined with GE- and SE-DSC perfusion sequences, and a quantitative blood-oxygen-level-dependent (qBOLD) approach...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28263417/methods-for-the-computation-of-templates-from-quantitative-magnetic-susceptibility-maps-qsm-toward-improved-atlas-and-voxel-based-analyses-vba
#12
Jannis Hanspach, Michael G Dwyer, Niels P Bergsland, Xiang Feng, Jesper Hagemeier, Nicola Bertolino, Paul Polak, Jürgen R Reichenbach, Robert Zivadinov, Ferdinand Schweser
PURPOSE: To develop and assess a method for the creation of templates for voxel-based analysis (VBA) and atlas-based approaches using quantitative magnetic susceptibility mapping (QSM). MATERIALS AND METHODS: We studied four strategies for the creation of magnetic susceptibility brain templates, derived as successive extensions of the conventional template generation (CONV) based on only T1 -weighted (T1 w) images. One method that used only T1 w images involved a minor improvement of CONV (U-CONV)...
March 6, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28261863/bone-quantitative-susceptibility-mapping-using-a-chemical-species-specific-r2-signal-model-with-ultrashort-and-conventional-echo-data
#13
Alexey V Dimov, Zhe Liu, Pascal Spincemaille, Martin R Prince, Jiang Du, Yi Wang
PURPOSE: To develop quantitative susceptibility mapping (QSM) of bone using an ultrashort echo time (UTE) gradient echo (GRE) sequence for signal acquisition and a bone-specific effective transverse relaxation rate ( R2*) to model water-fat MR signals for field mapping. METHODS: Three-dimensional radial UTE data (echo times ≥ 40 μs) was acquired on a 3 Tesla scanner and fitted with a bone-specific signal model to map the chemical species and susceptibility field...
March 5, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28251685/primal-dual-and-forward-gradient-implementation-for-quantitative-susceptibility-mapping
#14
Youngwook Kee, Kofi Deh, Alexey Dimov, Pascal Spincemaille, Yi Wang
PURPOSE: To investigate the computational aspects of the prior term in quantitative susceptibility mapping (QSM) by (i) comparing the Gauss-Newton conjugate gradient (GNCG) algorithm that uses numerical conditioning (ie, modifies the prior term) with a primal-dual (PD) formulation that avoids this, and (ii) carrying out a comparison between a central and forward difference scheme for the discretization of the prior term. THEORY AND METHODS: A spatially continuous formulation of the regularized QSM inversion problem and its PD formulation were derived...
March 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28247561/the-challenge-of-bias-free-coil-combination-for-quantitative-susceptibility-mapping-at-ultra-high-field
#15
Steffen Bollmann, Simon Daniel Robinson, Kieran O'Brien, Viktor Vegh, Andrew Janke, Lars Marstaller, David Reutens, Markus Barth
PURPOSE: Quantitative susceptibility mapping is a technique to estimate the magnetic property of tissue with particularly high sensitivity at ultra-high field. However, a key challenge at ultra-high field is the combination of phase data acquired using phased array receive coils. Several methods for combining phase data have been proposed, but the influence of coil combination choices on susceptibility quantitation has not been studied systematically. METHODS: We combined phase data using COMPOSER (COMbining Phase data using a Short Echo-time Reference scan) and a reference-free channel-by-channel method...
March 1, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28221362/disrupted-iron-regulation-in-the-brain-and-periphery-in-cocaine-addiction
#16
K D Ersche, J Acosta-Cabronero, P S Jones, H Ziauddeen, R P L van Swelm, C M M Laarakkers, R Raha-Chowdhury, G B Williams
Stimulant drugs acutely increase dopamine neurotransmission in the brain, and chronic use leads to neuroadaptive changes in the mesolimbic dopamine system and morphological changes in basal ganglia structures. Little is known about the mechanisms underlying these changes but preclinical evidence suggests that iron, a coenzyme in dopamine synthesis and storage, may be a candidate mediator. Iron is present in high concentrations in the basal ganglia and stimulant drugs may interfere with iron homeostasis. We hypothesised that morphological brain changes in cocaine addiction relate to abnormal iron regulation in the brain and periphery...
February 21, 2017: Translational Psychiatry
https://www.readbyqxmd.com/read/28215716/validation-of-a-quantitative-susceptibility-mapping-acquisition-and-reconstruction-pipeline-using-a-new-iron-sucrose-based-mr-susceptibility-phantom
#17
Jeremy Deverdun, François Molino, Nicolas Menjot de Champfleur, Emmanuelle Le Bars
PURPOSE: Quantitative susceptibility mapping is a new technique and its processing pipeline has to be validated before clinical practice. We described an easy to build magnetic resonance (MR) susceptibility phantom based on iron sucrose. MATERIALS AND METHODS: In a plastic container, Eppendorf tubes containing increasing iron sucrose concentration ranging from 0 to 60μg Fe/mL were inserted in an agarose gel. To estimate susceptibility, multiple coronal gradient echo acquisitions were performed with varying angle of the phantom relative to the B0 field, ranging from 30 to 90°...
February 16, 2017: Journal of Neuroradiology. Journal de Neuroradiologie
https://www.readbyqxmd.com/read/28207389/an-efficient-reconstruction-algorithm-based-on-the-alternating-direction-method-of-multipliers-for-joint-estimation-of-r2-and-off-resonance-in-fmri
#18
Chenxi Hu, Stanley Reeves, Dana Peters, Donald Twieg
R 2 mapping is a useful tool in blood-oxygen-level dependent (BOLD) fMRI due to its quantitative nature. However, like T 2 -weighted imaging, standard R 2 mapping based on multiecho EPI suffers from geometric distortion, due to strong offresonance near the air-tissue interface. Joint mapping of R 2 and off-resonance can correct the geometric distortion and is less susceptible to motion artifacts. Single-shot joint mapping of R 2 and off-resonance is possible with a rosette trajectory due to its frequent sampling of the k-space center...
February 13, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28188873/an-improved-fsl-first-pipeline-for-subcortical-gray-matter-segmentation-to-study-abnormal-brain-anatomy-using-quantitative-susceptibility-mapping-qsm
#19
Xiang Feng, Andreas Deistung, Michael G Dwyer, Jesper Hagemeier, Paul Polak, Jessica Lebenberg, Frédérique Frouin, Robert Zivadinov, Jürgen R Reichenbach, Ferdinand Schweser
Accurate and robust segmentation of subcortical gray matter (SGM) nuclei is required in many neuroimaging applications. FMRIB's Integrated Registration and Segmentation Tool (FIRST) is one of the most popular software tools for automated subcortical segmentation based on T1-weighted (T1w) images. In this work, we demonstrate that FIRST tends to produce inaccurate SGM segmentation results in the case of abnormal brain anatomy, such as present in atrophied brains, due to a poor spatial match of the subcortical structures with the training data in the MNI space as well as due to insufficient contrast of SGM structures on T1w images...
February 7, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28184981/association-mapping-utilizing-diverse-barley-lines-reveals-net-form-net-blotch-seedling-resistance-susceptibility-loci
#20
Jonathan K Richards, Timothy L Friesen, Robert S Brueggeman
A diverse collection of barley lines was phenotyped with three North American Pyrenophora teres f. teres isolates and association analyses detected 78 significant marker-trait associations at 16 genomic loci. Pyrenophora teres f. teres is a necrotrophic fungal pathogen and the causal agent of the economically important foliar disease net form net blotch (NFNB) of barley. The deployment of effective and durable resistance against P. teres f. teres has been hindered by the complexity of quantitative resistance and susceptibility...
February 9, 2017: TAG. Theoretical and Applied Genetics. Theoretische und Angewandte Genetik
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