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https://www.readbyqxmd.com/read/28797738/tissue-magnetic-susceptibility-mapping-as-a-marker-of-tau-pathology-in-alzheimer-s-disease
#1
J O'Callaghan, H Holmes, N Powell, J A Wells, O Ismail, I F Harrison, B Siow, R Johnson, Z Ahmed, A Fisher, S Meftah, M J O'Neill, T K Murray, E C Collins, K Shmueli, M F Lythgoe
Alzheimer's disease is connected to a number of other neurodegenerative conditions, known collectively as 'tauopathies', by the presence of aggregated tau protein in the brain. Neuroinflammation and oxidative stress in AD are associated with tau pathology and both the breakdown of axonal sheaths in white matter tracts and excess iron accumulation grey matter brain regions. Despite the identification of myelin and iron concentration as major sources of contrast in quantitative susceptibility maps of the brain, the sensitivity of this technique to tau pathology has yet to be explored...
August 4, 2017: NeuroImage
https://www.readbyqxmd.com/read/28791783/quantitative-susceptibility-mapping-as-a-monitoring-biomarker-in-cerebral-cavernous-malformations-with-recent-hemorrhage
#2
Hussein A Zeineddine, Romuald Girard, Ying Cao, Nicholas Hobson, Maged D Fam, Agnieszka Stadnik, Huan Tan, Jingjing Shen, Kiranj Chaudagar, Robert Shenkar, Richard E Thompson, Nichol McBee, Daniel Hanley, Timothy Carroll, Gregory A Christoforidis, Issam A Awad
BACKGROUND: Quantitative Susceptibility Mapping (QSM) MRI allows accurate assessment of iron content in cerebral cavernous malformations (CCM), and a threshold increase by 6% in QSM has been shown to reflect new symptomatic hemorrhage (SH) in previously stable lesions. PURPOSE/HYPOTHESIS: It is unclear how lesional QSM evolves in CCMs after recent SH, and whether this could serve as a monitoring biomarker in clinical trials aimed at preventing rebleeding in these lesions...
August 9, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28762243/quantitative-susceptibility-mapping-report-from-the-2016-reconstruction-challenge
#3
Christian Langkammer, Ferdinand Schweser, Karin Shmueli, Christian Kames, Xu Li, Li Guo, Carlos Milovic, Jinsuh Kim, Hongjiang Wei, Kristian Bredies, Sagar Buch, Yihao Guo, Zhe Liu, Jakob Meineke, Alexander Rauscher, José P Marques, Berkin Bilgic
PURPOSE: The aim of the 2016 quantitative susceptibility mapping (QSM) reconstruction challenge was to test the ability of various QSM algorithms to recover the underlying susceptibility from phase data faithfully. METHODS: Gradient-echo images of a healthy volunteer acquired at 3T in a single orientation with 1.06 mm isotropic resolution. A reference susceptibility map was provided, which was computed using the susceptibility tensor imaging algorithm on data acquired at 12 head orientations...
July 31, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28747100/loading-and-elution-characteristics-of-quadrasphere-microspheres-loaded-with-bevacizumab
#4
Martin Oselkin, Neda I Sedora-Roman, Bryan A Pukenas, David Kung, Robert W Hurst
AIM: Super absorbent polyvinyl alcohol-sodium acrylate copolymer microspheres, Quadrasphere microspheres (QSM), are commonly used for drug-eluting bead therapy, however, the literature only reports its use with small molecule chemotherapeutics. This study evaluates the loading and elution characteristics of bevacizumab-loaded QSM. METHODS & RESULTS: A single vial of QSM was reconstituted with 200 mg of bevacizumab. Drug concentration was determined by ELISA immunoassay...
July 27, 2017: Therapeutic Delivery
https://www.readbyqxmd.com/read/28731570/susceptibility-weighted-imaging-and-quantitative-susceptibility-mapping-of-the-cerebral-vasculature-using-ferumoxytol
#5
Saifeng Liu, Jean-Christophe Brisset, Jiani Hu, E Mark Haacke, Yulin Ge
PURPOSE: To demonstrate the potential of imaging cerebral arteries and veins with ferumoxytol using susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM). MATERIALS AND METHODS: The relationships between ferumoxytol concentration and the apparent susceptibility at 1.5T, 3T, and 7T were determined using phantom data; the ability of visualizing subvoxel vessels was evaluated using simulations; and the feasibility of using ferumoxytol to enhance the visibility of small vessels was confirmed in three healthy volunteers at 7T(with doses 1 mg/kg to 4 mg/kg)...
July 21, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28689259/differential-diagnosis-of-parkinsonism-by-a-combined-use-of-diffusion-kurtosis-imaging-and-quantitative-susceptibility-mapping
#6
Kenji Ito, Chigumi Ohtsuka, Kunihiro Yoshioka, Hiroyuki Kameda, Suguru Yokosawa, Ryota Sato, Yasuo Terayama, Makoto Sasaki
PURPOSE: We investigated whether diffusion kurtosis imaging (DKI) and quantitative susceptibility mapping (QSM) could detect pathological changes that occur in Parkinson's disease (PD), multiple system atrophy with predominant parkinsonism (MSA-P) or predominant cerebellar ataxia (MSA-C), and progressive supranuclear palsy syndrome (PSPS) and thus be used for differential diagnosis that is often difficult. METHODS: Seventy patients (41 with PD, 6 with MSA-P, 7 with MSA-C, 16 with PSPS) and 20 healthy controls were examined using a 3...
August 2017: Neuroradiology
https://www.readbyqxmd.com/read/28674518/brain-susceptibility-changes-in-a-patient-with-natalizumab-related-progressive-multifocal-leukoencephalopathy-a-longitudinal-quantitative-susceptibility-mapping-and-relaxometry-study
#7
Giuseppe Pontillo, Sirio Cocozza, Roberta Lanzillo, Pasquale Borrelli, Anna De Rosa, Vincenzo Brescia Morra, Enrico Tedeschi, Giuseppe Palma
BACKGROUND: Brain MRI plays an essential role in both diagnosis and follow-up of the JC virus infection of the brain. Recently, MR studies with susceptibility-weighted imaging (SWI) sequences have shown hypointensities in U-fibers adjacent to white matter (WM) lesions of progressive multifocal leukoencephalopathy (PML). This finding has been confirmed with the use of quantitative susceptibility mapping (QSM), allowing to hypothesize a paramagnetic effect in these regions. Here, we report the first longitudinal assessment of QSM and R2* maps in natalizumab-associated PML to evaluate serial changes in susceptibility contrast images and their role in PML diagnosis and follow-up...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28669058/improved-neuroimaging-atlas-of-the-dentate-nucleus
#8
Naying He, Jason Langley, Daniel E Huddleston, Huawei Ling, Hongmin Xu, Chunlei Liu, Fuhua Yan, Xiaoping P Hu
The dentate nucleus (DN) of the cerebellum is the major output nucleus of the cerebellum and is rich in iron. Quantitative susceptibility mapping (QSM) provides better iron-sensitive MRI contrast to delineate the boundary of the DN than either T2-weighted images or susceptibility-weighted images. Prior DN atlases used T2-weighted or susceptibility-weighted images to create DN atlases. Here, we employ QSM images to develop an improved dentate nucleus atlas for use in imaging studies. The DN was segmented in QSM images from 38 healthy volunteers...
July 1, 2017: Cerebellum
https://www.readbyqxmd.com/read/28664033/decreased-susceptibility-of-major-veins-in-mild-traumatic-brain-injury-is-correlated-with-post-concussive-symptoms-a-quantitative-susceptibility-mapping-study
#9
Chao Chai, Rui Guo, Chao Zuo, Linlin Fan, Saifeng Liu, Tianyi Qian, E Mark Haacke, Shuang Xia, Wen Shen
Cerebral venous oxygen saturation (SvO2) is an important biomarker of brain function. In this study, we aimed to explore the relative changes of regional cerebral SvO2 among axonal injury (AI) patients, non-AI patients and healthy controls (HCs) using quantitative susceptibility mapping (QSM). 48 patients and 32 HCs were enrolled. The patients were divided into two groups depending on the imaging based evidence of AI. QSM was used to measure the susceptibility of major cerebral veins. Nonparametric testing was performed for susceptibility differences among the non-AI patient group, AI patient group and healthy control group...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28663515/noninvasive-assessment-of-oxygen-extraction-fraction-in-chronic-ischemia-using-quantitative-susceptibility-mapping-at-7-tesla
#10
Ikuko Uwano, Kohsuke Kudo, Ryota Sato, Kuniaki Ogasawara, Hiroyuki Kameda, Jun-Ichi Nomura, Futoshi Mori, Fumio Yamashita, Kenji Ito, Kunihiro Yoshioka, Makoto Sasaki
BACKGROUND AND PURPOSE: The oxygen extraction fraction (OEF) is an effective metric to evaluate metabolic reserve in chronic ischemia. However, OEF is considered to be accurately measured only when using positron emission tomography (PET). Thus, we investigated whether OEF maps generated by magnetic resonance quantitative susceptibility mapping (QSM) at 7 Tesla enabled detection of OEF changes when compared with those obtained with PET. METHODS: Forty-one patients with chronic stenosis/occlusion of the unilateral internal carotid artery or middle cerebral artery were examined using 7 Tesla-MRI and PET scanners...
June 29, 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/28653375/cardiac-quantitative-susceptibility-mapping-qsm-for-heart-chamber-oxygenation
#11
Yan Wen, Thanh D Nguyen, Zhe Liu, Pascal Spincemaille, Dong Zhou, Alexey Dimov, Youngwook Kee, Kofi Deh, Jiwon Kim, Jonathan W Weinsaft, Yi Wang
PURPOSE: To demonstrate the feasibility of in vivo quantitative susceptibility mapping (QSM) in cardiac MRI and to show that mixed-venous oxygen saturation (SvO2 ) can be measured non-invasively using QSM. METHODS: Electrocardiographic-gated multi-echo 2D gradient echo data were collected at 1.5 T from 14 healthy volunteers during successive breath-holds. Phase wraps and fat chemical shift were removed using a graph-cut-based phase analysis and IDEAL in an iterative approach...
June 26, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28631203/assessment-of-mri-contrast-agent-concentration-by-quantitative-susceptibility-mapping-qsm-application-to-estimation-of-cerebral-blood-volume-during-steady-state
#12
Emelie Lind, Linda Knutsson, Robin Kämpe, Freddy Ståhlberg, Ronnie Wirestam
OBJECTIVE: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. MATERIALS AND METHODS: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test-retest study...
June 19, 2017: Magma
https://www.readbyqxmd.com/read/28602813/automated-segmentation-of-midbrain-structures-with-high-iron-content
#13
REVIEW
Benjamín Garzón, Rouslan Sitnikov, Lars Bäckman, Grégoria Kalpouzos
The substantia nigra (SN), the subthalamic nucleus (STN), and the red nucleus (RN) are midbrain structures of ample interest in many neuroimaging studies, which may benefit from the availability of automated segmentation methods. The high iron content of these structures awards them high contrast in quantitative susceptibility mapping (QSM) images. We present a novel segmentation method that leverages the information of these images to produce automated segmentations of the SN, STN, and RN. The algorithm builds a map of spatial priors for the structures by non-linearly registering a set of manually-traced training labels to the midbrain...
June 9, 2017: NeuroImage
https://www.readbyqxmd.com/read/28601374/quantitative-susceptibility-mapping-qsm-and-r2-in-the-human-brain-at-3t-evaluation-of-intra-scanner-repeatability
#14
Xiang Feng, Andreas Deistung, Jürgen R Reichenbach
Quantitative susceptibility mapping (QSM) and the effective transverse relaxation rate (R2*) can be used to monitor iron and myelin content in brain tissue, which are both subject to changes in many neurological diseases but also during healthy aging. In this study, we quantitatively assessed the repeatability of QSM and R2* by applying four independent scans in eight young healthy, female subjects on a 3T MRI scanner. Since QSM does not yield absolute values for bulk magnetic susceptibilities, we additionally investigated the influence of the choice of a reference brain region for susceptibility by computing susceptibility differences with respect to five different brain structures (whole brain, frontal white matter (fWM), internal capsule (IC), cerebrospinal fluid (CSF) in the lateral ventricle, cortical gray matter (cGM))...
June 7, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28595120/background-field-removal-using-a-region-adaptive-kernel-for-quantitative-susceptibility-mapping-of-human-brain
#15
Jinsheng Fang, Lijun Bao, Xu Li, Peter C M van Zijl, Zhong Chen
Background field removal is an important MR phase preprocessing step for quantitative susceptibility mapping (QSM). It separates the local field induced by tissue magnetic susceptibility sources from the background field generated by sources outside a region of interest, e.g. brain, such as air-tissue interface. In the vicinity of air-tissue boundary, e.g. skull and paranasal sinuses, where large susceptibility variations exist, present background field removal methods are usually insufficient and these regions often need to be excluded by brain mask erosion at the expense of losing information of local field and thus susceptibility measures in these regions...
May 10, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28580758/nuclei-specific-deposits-of-iron-and-calcium-in-the-rat-thalamus-after-status-epilepticus-revealed-with-quantitative-susceptibility-mapping-qsm
#16
Manisha Aggarwal, Xu Li, Olli Gröhn, Alejandra Sierra
PURPOSE: To investigate pathological changes in the rat brain after pilocarpine-induced status epilepticus using quantitative susceptibility mapping (QSM). MATERIALS AND METHODS: 3D multiecho gradient-echo (GRE) data were acquired from ex vivo brains of pilocarpine-injected and age-matched control rats at 11.7T. Maps of R2* and quantitative susceptibility were calculated from the acquired 3D GRE magnitude and phase data, respectively. QSM and R2* maps were compared with Perls' (iron) and Alizarin-red-S (calcium) stainings in the same brains to investigate the pathophysiological basis of susceptibility contrast...
June 5, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28571703/diagnosis-of-intracranial-calcification-and-hemorrhage-in-pediatric-patients-comparison-of-quantitative-susceptibility-mapping-and-phase-images-of-susceptibility-weighted-imaging
#17
S Ciraci, K Gumus, S Doganay, M S Dundar, G D Kaya Ozcora, S B Gorkem, H Per, A Coskun
PURPOSE: To prospectively compare the diagnostic capabilities of quantitative susceptibility mapping (QSM) with those of phase images of susceptibility-weighted imaging (SWI) in the detection and differentiation of intracranial calcification and hemorrhage in pediatric patients. METHOD: Sixteen pediatric patients (9 girls, 7 boys) with a mean age of 9.4±6.3 (SD) years (range, 6 days-15 years) were included. Fifty-nine calcifications and 31 hemorrhages were detected...
May 29, 2017: Diagnostic and Interventional Imaging
https://www.readbyqxmd.com/read/28556247/enhanced-quantitative-susceptibility-mapping-qsm-using-real-time-field-control
#18
Pinar Senay Özbay, Yolanda Duerst, Bertram Jakob Wilm, Klaas Paul Pruessmann, Daniel Nanz
PURPOSE: To assess the potential of a real-time field-control (FC) system for mitigating effects of spatiotemporal field fluctuations in quantitative susceptibility mapping (QSM) at 7 T. METHODS: Magnitude, phase, and QSM images of phantoms and healthy volunteers were acquired under standard conditions and under induced field perturbation (FP) (phantoms: periodic water-bottle displacement; volunteers: deep breathing and forearm movement) with and without FC, which continuously detects and minimizes magnetic-field variations...
May 28, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28556244/coherence-enhancement-in-quantitative-susceptibility-mapping-by-means-of-anisotropic-weighting-in-morphology-enabled-dipole-inversion
#19
Youngwook Kee, Junghun Cho, Kofi Deh, Zhe Liu, Pascal Spincemaille, Yi Wang
PURPOSE: To investigate an anisotropic structural prior in morphology enabled dipole inversion (MEDI) for improving accuracy in quantitative susceptibility mapping (QSM). THEORY AND METHODS: Anisotropic weighting (AW) was devised and implemented to incorporate orientation information into the edge agreement in the MEDI method. AW performance was compared with isotropic weighting by testing and validating on in vivo brain multiple orientation MRI data using COSMOS and the (33) component of the susceptibility tensor as reference...
May 28, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28531270/utilization-of-quantitative-susceptibility-mapping-for-direct-targeting-of-the-subthalamic-nucleus-during-deep-brain-stimulation-surgery
#20
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.)
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