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https://www.readbyqxmd.com/read/28531270/utilization-of-quantitative-susceptibility-mapping-for-direct-targeting-of-the-subthalamic-nucleus-during-deep-brain-stimulation-surgery
#1
Jonathan Rasouli, Ritesh Ramdhani, Fedor E Panov, Alexey Dimov, Yan Zhang, Catherine Cho, Yi Wang, Brian Harris Kopell
BACKGROUND: Deep brain stimulation of the subthalamic nucleus (STN) has demonstrated efficacy in improving motor disability in Parkinson's disease. The recently developed quantitative susceptibility mapping (QSM) technique, which can accurately map iron deposits in deep brain nuclei, promises precise targeting of the STN. OBJECTIVE: To demonstrate the use of QSM to target STN effectively by correlating with classical physiological-based targeting measures in a prospective study...
May 21, 2017: Operative Neurosurgery (Hagerstown, Md.)
https://www.readbyqxmd.com/read/28526432/quantitative-susceptibility-mapping-using-principles-of-echo-shifting-with-a-train-of-observations-sequence-on-1-5t-mri
#2
Hirohito Kan, Nobuyuki Arai, Harumasa Kasai, Hiroshi Kunitomo, Yasujiro Hirose, Yuta Shibamoto
PURPOSE: To evaluate the accuracy of susceptibility estimated from the principles of echo shifting with a train of observations (PRESTO) sequence using a 1.5T MRI system, we conducted experiments on the human brain using the PRESTO sequence and compared our results with the susceptibility obtained from spoiled gradient-recalled echo (GRE) sequence with flow compensation using quantitative susceptibility mapping (QSM) reconstruction. MATERIALS AND METHODS: Experiments on the human brain were conducted on 12 healthy volunteers (27±4years) using PRESTO and spoiled GRE sequences on a 1...
May 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28515413/magnetic-susceptibility-changes-in-the-basal-ganglia-and-brain-stem-of-patients-with-wilson-s-disease-evaluation-with-quantitative-susceptibility-mapping
#3
Selim Doganay, Kazim Gumus, Gonca Koc, Ayse Kacar Bayram, Mehmet Sait Dogan, Duran Arslan, Hakan Gumus, Sureyya Burcu Gorkem, Saliha Ciraci, Halil Ibrahim Serin, Abdulhakim Coskun
OBJECTIVES: Wilson's disease (WD) is characterized with the accumulation of copper in the liver and brain. The objective of this study is to quantitatively measure the susceptibility changes of basal ganglia and brain stem of pediatric patients with neurological WD using quantitative susceptibility mapping (QSM) in comparison to healthy controls. METHODS: Eleven patients with neurological WD (mean age 15 ± 3.3 years, range 10-22 years) and 14 age-matched controls were prospectively recruited...
May 18, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28477179/contribution-of-qsm-imaging-to-the-diagnosis-of-the-rare-syndrome-of-leukoencephalopathy-with-cysts-and-calcification-lcc
#4
Peter Raab, Martin Stangel, Heinrich Lanfermann
We describe the typical computed tomography (CT) and magnetic resonance imaging (MRI) characteristics in a rare case of adult leukoencephalopathy with calcifications and cysts (LCC). In addition, we describe the specific findings of quantified susceptibility mapping (QSM) in this case, relate it to known histopathological findings, and point out possible advantages of this method.
May 5, 2017: Clinical Neuroradiology
https://www.readbyqxmd.com/read/28470768/susceptibility-sensitive-mri-of-multiple-sclerosis-lesions-and-the-impact-of-normal-appearing-white-matter-changes
#5
Vanessa Wiggermann, Simon Hametner, Enedino Hernández-Torres, Christian Kames, Verena Endmayr, Gregor Kasprian, Romana Höftberger, David K B Li, Anthony Traboulsee, Alexander Rauscher
Susceptibility-sensitive magnetic resonance imaging (MRI) has gained importance in multiple sclerosis (MS) research because of its versatility, high resolution and excellent sensitivity to changes in tissue structure and composition. In particular, mapping of the resonance frequency of the MR signal and quantitative susceptibility mapping (QSM) have been explored for the description of MS lesions. Many current studies utilizing these techniques attribute increases in the MR frequency or QSM to elevated tissue iron content, in addition to myelin loss...
May 4, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28465264/quantitative-susceptibility-mapping-as-a-possible-tool-to-radiographically-diagnose-sentinel-headache-associated-with-intracranial-aneurysm-case-report
#6
Daichi Nakagawa, Cameron Cushing, Yasunori Nagahama, Lauren Allan, David Hasan
BACKGROUND: Sentinel headache (SH) is estimated to occur prior to rupture of an aneurysm in 15-60% of aneurysmal subarachnoid hemorrhage (aSAH) cases. Non-contrasted computed tomography (CT) of brain and lumbar puncture are both negative, by definition, in patients presenting with SH. One of the theories explaining this phenomenon is micro-hemorrhage (MH) from the aneurysm wall contributing to iron deposition in the interface between the aneurysm wall and brain parenchyma. Quantitative susceptibility mapping (QSM) is a recently introduced magnetic resonance imaging (MRI) technique that has been shown capable of localizing the deposition of paramagnetic metals, particularly ferric iron...
April 29, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28438711/can-transverse-relaxation-rates-in-deep-gray-matter-be-approximated-from-functional-and-t2-weighted-flair-scans-for-relative-brain-iron-quantification
#7
Benjamín Garzón, Rouslan Sitnikov, Lars Bäckman, Grégoria Kalpouzos
Alterations in iron concentration in certain deep gray matter regions are known to occur in aging and several clinical conditions. In vivo measurements of R2(∗) transverse relaxation rates and quantitative susceptibility mapping (QSM) have been shown to be strongly correlated with iron concentration in tissue, but their calculation requires the acquisition of a multi-echo gradient recalled echo sequence (MGRE). In the current study, we examined the feasibility of approximating R2(∗) rates using metrics derived from fMRI-EPI and T2-weighted FLAIR images, which are widely available...
April 21, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28435102/simultaneous-time-interleaved-multislice-stims-for-rapid-susceptibility-weighted-acquisition
#8
Berkin Bilgic, Huihui Ye, Lawrence L Wald, Kawin Setsompop
T2⁎ weighted 3D Gradient Echo (GRE) acquisition is the main sequence used for Susceptibility Weighted Imaging (SWI) and Quantitative Susceptibility Mapping (QSM). These applications require a long echo time (TE) to build up phase contrast, requiring a long repetition time (TR), and leading to excessively lengthy scans. The long TE acquisition creates a significant amount of unused time within each TR, which can be utilized for either multi-echo sampling or additional image encoding with the echo-shift technique...
April 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28424610/characterizing-brain-iron-deposition-in-patients-with-subcortical-vascular-mild-cognitive-impairment-using-quantitative-susceptibility-mapping-a-potential-biomarker
#9
Yawen Sun, Xin Ge, Xu Han, Wenwei Cao, Yao Wang, Weina Ding, Mengqiu Cao, Yong Zhang, Qun Xu, Yan Zhou, Jianrong Xu
The presence and pattern of iron accumulation in subcortical vascular mild cognitive impairment (svMCI) and their effects on cognition have rarely been investigated. We aimed to examine brain iron deposition in svMCI subjects using quantitative susceptibility mapping (QSM). Moreover, we aimed to investigate the correlation between brain iron deposition and the severity of cognitive impairment as indicated by z-scores. We recruited 20 subcortical ischemic vascular disease (SIVD) patients who fulfilled the criteria for svMCI...
2017: Frontiers in Aging Neuroscience
https://www.readbyqxmd.com/read/28423027/comparison-of-t2-weighted-and-qsm-contrasts-in-parkinson-s-disease-to-visualize-the-stn-with-mri
#10
Anneke Alkemade, Gilles de Hollander, Max C Keuken, Andreas Schäfer, Derek V M Ott, Johannes Schwarz, David Weise, Sonja A Kotz, Birte U Forstmann
The subthalamic nucleus (STN) plays a crucial role in the surgical treatment of Parkinson's disease (PD). Studies investigating optimal protocols for STN visualization using state of the art magnetic resonance imaging (MRI) techniques have shown that susceptibility weighted images, which display the magnetic susceptibility distribution, yield better results than T1-weighted, T2-weighted, and T2*-weighted contrasts. However, these findings are based on young healthy individuals, and require validation in elderly individuals and persons suffering from PD...
2017: PloS One
https://www.readbyqxmd.com/read/28392492/pulse-sequences-and-parallel-imaging-for-high-spatiotemporal-resolution-mri-at-ultra-high-field
#11
Benedikt A Poser, Kawin Setsompop
The SNR and CNR benefits of ultra-high field (UHF) have helped push the envelope of achievable spatial resolution in MRI. For applications based on susceptibility contrast where there is a large CNR gain, high quality sub-millimeter resolution imaging is now being routinely performed, particularly in fMRI and phase imaging/QSM. This has enabled the study of structure and function of very fine-scale structures in the brain. UHF has also helped push the spatial resolution of many other MRI applications as will be outlined in this review...
April 6, 2017: NeuroImage
https://www.readbyqxmd.com/read/28391484/genomic-and-molecular-characterization-of-a-novel-quorum-sensing-molecule-in-bacillus-licheniformis
#12
Elham Esmaeilishirazifard, Daniela De Vizio, Sterghios A Moschos, Tajalli Keshavarz
Quorum sensing molecules (QSMs) are involved in the regulation of complicated processes helping bacterial populations respond to changes in their cell-density. Although the QS gene cluster (comQXPA) has been identified in the genome sequence of some bacilli, the QS system B. licheniformis has not been investigated in detail, and its QSM (ComX pheromone) has not been identified. Given the importance of this antagonistic bacterium as an industrial workhorse, this study was aimed to elucidate B. licheniformis NCIMB-8874 QS...
December 2017: AMB Express
https://www.readbyqxmd.com/read/28380758/few-mode-fiber-based-raman-distributed-temperature-sensing
#13
Meng Wang, Hao Wu, Ming Tang, Zhiyong Zhao, Yunli Dang, Can Zhao, Ruolin Liao, Wen Chen, Songnian Fu, Chen Yang, Weijun Tong, Perry Ping Shum, Deming Liu
We proposed and experimentally demonstrated a few mode fiber (FMF) based Raman distributed temperature sensor (RDTS) to extend the sensing distance with enhanced signal-to-noise ratio (SNR) of backscattered anti-Stokes spontaneous Raman scattering. Operating in the quasi-single mode (QSM) with efficient fundamental mode excitement, the FMF allows much larger input pump power before the onset of stimulated Raman scattering compared with the standard single mode fiber (SSMF) and mitigates the detrimental differential mode group delay (DMGD) existing in the conventional multimode fiber (MMF) based RDTS system...
March 6, 2017: Optics Express
https://www.readbyqxmd.com/read/28367904/quantitative-susceptibility-mapping-using-the-multiple-dipole-inversion-combination-with-k-space-segmentation-method
#14
Ryota Sato, Toru Shirai, Yo Taniguchi, Takenori Murase, Yoshitaka Bito, Hisaaki Ochi
Quantitative susceptibility mapping (QSM) is a new magnetic resonance imaging (MRI) technique for noninvasively estimating the magnetic susceptibility of biological tissue. Several methods for QSM have been proposed. One of these methods can estimate susceptibility with high accuracy in tissues whose contrast is consistent between magnitude images and susceptibility maps, such as deep gray-matter nuclei. However, the susceptibility of small veins is underestimated and not well depicted by using the above approach, because the contrast of small veins is inconsistent between a magnitude image and a susceptibility map...
March 27, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28338046/solitary-perturbations-in-the-steep-boundary-of-magnetized-toroidal-plasma
#15
J E Lee, G S Yun, W Lee, M H Kim, M Choi, J Lee, M Kim, H K Park, J G Bak, W H Ko, Y S Park
Solitary perturbations (SPs) localized both poloidally and radially are detected within ~100 μs before the partial collapse of the high pressure gradient boundary region (called pedestal) of magnetized toroidal plasma in the KSTAR tokamak device. The SP develops with a low toroidal mode number (typically unity) in the pedestal ingrained with quasi-stable edge-localized mode (QSM) which commonly appears during the inter-collapse period. The SPs have smaller mode pitch and different (often opposite) rotation velocity compared to the QSMs...
March 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28295954/clinical-quantitative-susceptibility-mapping-qsm-biometal-imaging-and-its-emerging-roles-in-patient-care
#16
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
#17
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/28289372/improved-quantification-of-cerebral-vein-oxygenation-using-partial-volume-correction
#18
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/28263417/methods-for-the-computation-of-templates-from-quantitative-magnetic-susceptibility-maps-qsm-toward-improved-atlas-and-voxel-based-analyses-vba
#19
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
#20
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
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