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https://www.readbyqxmd.com/read/29746715/quantitative-susceptibility-map-analysis-in-preterm-neonates-with-germinal-matrix-intraventricular-hemorrhage
#1
Domenico Tortora, Mariasavina Severino, Jan Sedlacik, Benedetta Toselli, Mariya Malova, Alessandro Parodi, Giovanni Morana, Marco Massimo Fato, Luca Antonio Ramenghi, Andrea Rossi
BACKGROUND: Germinal matrix-intraventricular hemorrhage (GMH-IVH) is a common form of intracranial hemorrhage occurring in preterm neonates that may affect normal brain development. Although the primary lesion is easily identified on MRI by the presence of blood products, its exact extent may not be recognizable with conventional sequences. Quantitative susceptibility mapping (QSM) quantify the spatial distribution of magnetic susceptibility within biological tissues, including blood degradation products...
May 10, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29738526/morphology-adaptive-total-variation-for-the-reconstruction-of-quantitative-susceptibility-map-from-the-magnetic-resonance-imaging-phase
#2
Li Guo, Yingjie Mei, Jijing Guan, Xiangliang Tan, Yikai Xu, Wufan Chen, Qianjin Feng, Yanqiu Feng
Quantitative susceptibility mapping (QSM) is a magnetic resonance imaging technique that quantifies the magnetic susceptibility distribution within biological tissues. QSM calculates the underlying magnetic susceptibility by deconvolving the tissue magnetic field map with a unit dipole kernel. However, this deconvolution problem is ill-posed. The morphology enabled dipole inversion (MEDI) introduces total variation (TV) to regularize the susceptibility reconstruction. However, MEDI results still contain artifacts near tissue boundaries because MEDI only imposes TV constraint on voxels inside smooth regions...
2018: PloS One
https://www.readbyqxmd.com/read/29730126/lorentzian-effects-in-magnetic-susceptibility-mapping-of-anisotropic-biological-tissues
#3
Dmitriy A Yablonskiy, Alexander L Sukstanskii
The ultimate goal of MRI is to provide information on biological tissue microstructure and function. Quantitative Susceptibility Mapping (QSM) is one of the newer approaches for studying tissue microstructure by means of measuring phase of Gradient Recalled Echo (GRE) MRI signal. The fundamental question in the heart of this approach is: what is the relationship between the net phase/frequency of the GRE signal from an imaging voxel and the underlying tissue microstructure at the cellular and sub-cellular levels? In the presence of external magnetic field, biological media (e...
April 26, 2018: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/29729391/in-vivo-quantitative-structural-imaging-of-the-human-midbrain-and-the-superior-colliculus-at-9-4t
#4
Joana R Loureiro, Marc Himmelbach, Thomas Ethofer, Rolf Pohmann, Pascal Martin, Jonas Bause, Klaus Scheffler, Wolfgang Grodd, Gisela E Hagberg
We explored anatomical details of the superior colliculus (SC) by in vivo magnetic resonance imaging (MRI) at 9.4T. The high signal-to-noise ratio allowed the acquisition of high resolution, multi-modal images with voxel sizes ranging between 176 × 132 × 600 μm and (800)3 μm. Quantitative mapping of the longitudinal relaxation rate R1, the effective transverse relaxation rate R2*, and the magnetic susceptibility QSM was performed in 14 healthy volunteers. The images were analyzed in native space as well as after normalization to a common brain space (MNI)...
May 2, 2018: NeuroImage
https://www.readbyqxmd.com/read/29722955/increased-iron-deposition-on-brain-quantitative-susceptibility-mapping-correlates-with-decreased-cognitive-function-in-alzheimer-s-disease
#5
Lei Du, Zifang Zhao, Ailing Cui, Yijiang Zhu, Lu Zhang, Jing Liu, Sumin Shi, Chao Fu, Xiaowei Han, Wenwen Gao, Tianbin Song, Lizhi Xie, Lei Wang, Shilong Sun, Runcai Guo, Guolin Ma
The excessive accumulation of iron in deep gray structures is an important pathological characteristic in patients with Alzheimer's disease (AD). Quantitative susceptibility mapping (QSM) is more specific than other imaging-based iron measurements modalities and allows non-invasively assessment of tissue magnetic susceptibility, which has been shown to correlate well to the brain iron levels. This study aimed to investigate the correlations between the magnetic susceptibility values of deep gray matter nuclei and the cognitive functions assessed by mini-mental state examination (MMSE) and montreal cognitive assessment (MoCA) in patients with the mild and moderate AD...
May 3, 2018: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/29694688/quantitative-susceptibility-mapping-and-23-na-imaging-based-in-vitro-characterization-of-blood-clotting-kinetics
#6
Till M Schneider, Armin M Nagel, Markus Zorn, Andreas Wetscherek, Martin Bendszus, Mark E Ladd, Sina Straub
Blood clotting is a fundamental biochemical process in post-hemorrhagic hemostasis. Although the varying appearance of coagulating blood in T1 - and T2 -weighted images is widely used to qualitatively determine bleeding age, the technique permits only a rough discrimination of coagulation stages, and it remains difficult to distinguish acute and chronic hemorrhagic stages because of low T1 - and T2 -weighted signal intensities in both instances. To investigate new biomedical parameters for magnetic resonance imaging-based characterization of blood clotting kinetics, sodium imaging and quantitative susceptibility mapping (QSM) were compared with conventional T1 - and T2 -weighted imaging, as well as with biochemical hemolysis parameters...
April 25, 2018: NMR in Biomedicine
https://www.readbyqxmd.com/read/29687923/quantitative-susceptibility-mapping-of-articular-cartilage-ex-vivo-findings-at-multiple-orientations-and-following-different-degradation-treatments
#7
Olli Nykänen, Lassi Rieppo, Juha Töyräs, Ville Kolehmainen, Simo Saarakkala, Karin Shmueli, Mikko J Nissi
PURPOSE: We investigated the feasibility of quantitative susceptibility mapping (QSM) for assessing degradation of articular cartilage by measuring ex vivo bovine cartilage samples subjected to different degradative treatments. Specimens were scanned at several orientations to study if degradation affects the susceptibility anisotropy. T2*-mapping, histological stainings, and polarized light microscopy were used as reference methods. Additionally, simulations of susceptibility in layered geometry were performed...
April 24, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29687141/a-novel-antifungal-property-for-the-bacillus-licheniformis-comx-pheromone-and-its-possible-role-in-inter-kingdom-cross-talk
#8
Elham Esmaeilishirazifard, Aliakbar Dariush, Sterghios A Moschos, Tajalli Keshavarz
Quorum sensing molecules (QSMs) regulate, through a chemical communication process, multiple complex systems in bacterial and some fungal populations on the basis of cell density. The bacterial QSMs involved in inter-kingdom cross-talk may exhibit antagonistic activity against fungi. This provides an important opportunity for biocontrol of fungal invasion in plants. It has been shown that cultures of Bacillus spp. inhibit fungal growth. Here, we explore the inhibitory potential of the industrial workhorse Bacillus licheniformis NCIMB-8874 and its QSM (ComX pheromone) on the growth of Aspergillus flavus, a cereal, legume, and nut crop pathogen...
April 23, 2018: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/29675354/quantification-of-liver-iron-concentration-using-the-apparent-susceptibility-of-hepatic-vessels
#9
Saifeng Liu, Chaoyue Wang, Xiaoqi Zhang, Panli Zuo, Jiani Hu, E Mark Haacke, Hongyan Ni
Background: The quantification of liver iron concentration (LIC) is important for the monitoring of the body iron level in patients with iron overload. Conventionally, LIC is quantified through R2 or R2* mapping using MRI. In this paper, we demonstrate an alternative approach for LIC quantification through measuring the apparent susceptibility of hepatic vessels using quantitative susceptibility mapping (QSM). Methods: QSM was performed in the liver region with the iterative susceptibility weighted imaging and mapping (iSWIM) algorithm, using the geometry of the vessels extracted from magnitude images as constraints...
March 2018: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/29673893/a-new-discrete-dipole-kernel-for-quantitative-susceptibility-mapping
#10
Carlos Milovic, Julio Acosta-Cabronero, José Miguel Pinto, Hendrik Mattern, Marcelo Andia, Sergio Uribe, Cristian Tejos
PURPOSE: Most approaches for quantitative susceptibility mapping (QSM) are based on a forward model approximation that employs a continuous Fourier transform operator to solve a differential equation system. Such formulation, however, is prone to high-frequency aliasing. The aim of this study was to reduce such errors using an alternative dipole kernel formulation based on the discrete Fourier transform and discrete operators. METHODS: The impact of such an approach on forward model calculation and susceptibility inversion was evaluated in contrast to the continuous formulation both with synthetic phantoms and in vivo MRI data...
April 16, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29663939/brain-iron-distribution-after-multiple-doses-of-ultra-small-superparamagnetic-iron-oxide-particles-in-rats
#11
Andrew W Gorman, Kofi M Deh, Caspar M Schwiedrzik, Julie R White, Ernest Victor Groman, Clark A Fisher, Kelly M Gillen, Pascal Spincemaille, Skye Rasmussen, Martin R Prince, Henning U Voss, Winrich A Freiwald, Yi Wang
The purpose of this study is to determine the effects of high cumulative doses of ultra-small paramagnetic iron oxide (USPIO) used in neuroimaging studies. We intravenously administered 8 mg/kg of 2 USPIO compounds daily for 4 wk to male Sprague-Dawley rats (Crl:SD). Multiecho gradient-echo MRI, serum iron levels, and histology were performed at the end of dosing and after a 7-d washout period. R2* maps and quantitative susceptibility maps (QSM) were generated from multiecho gradient-echo data. R2* maps and QSM showed iron accumulation in brain ventricles on MR images acquired at the 4- and 5-wk time points...
April 2, 2018: Comparative Medicine
https://www.readbyqxmd.com/read/29659131/quantitative-susceptibility-mapping-across-two-clinical-field-strengths-contrast-to-noise-ratio-enhancement-at-1-5t
#12
Matteo Ippoliti, Lisa C Adams, Brenner Winfried, Bernd Hamm, Pascal Spincemaille, Yi Wang, Marcus R Makowski
BACKGROUND: Quantitative susceptibility mapping (QSM) is an MRI postprocessing technique that allows quantification of the spatial distribution of tissue magnetic susceptibility in vivo. Contributing sources include iron, blood products, calcium, myelin, and lipid content. PURPOSE: To evaluate the reproducibility and consistency of QSM across clinical field strengths of 1.5T and 3T and to optimize the contrast-to-noise ratio (CNR) at 1.5T through bandwidth tuning...
April 16, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29643036/-quantitative-magnetic-resonance-imaging-of-brain-iron-deposition-comparison-between-quantitative-susceptibility-mapping-and-transverse-relaxation-rate-r2-mapping
#13
Ji-Jing Guan, Yan-Qiu Feng
OBJECTIVE: To evaluate the accuracy and sensitivity of quantitative susceptibility mapping (QSM) and transverse relaxation rate (R2*) mapping in the measurement of brain iron deposition. METHODS: Super paramagnetic iron oxide (SPIO) phantoms and mouse models of Parkinson's disease (PD) related to iron deposition in the substantia nigra (SN) underwent 7.0 T magnetic resonance (MR) scans (Bruker, 70/16) with a multi-echo 3D gradient echo sequence, and the acquired data were processed to obtain QSM and R2*...
March 20, 2018: Nan Fang Yi Ke da Xue Xue Bao, Journal of Southern Medical University
https://www.readbyqxmd.com/read/29629545/diagnosis-of-early-stage-idiopathic-parkinson-s-disease-using-high-resolution-quantitative-susceptibility-mapping-combined-with-histogram-analysis-in-the-substantia-nigra-at-3-t
#14
Eung Yeop Kim, Young Hee Sung, Hyeong Geol Shin, Young Noh, Yoonho Nam, Jongho Lee
BACKGROUND AND PURPOSE: To test whether nigrosome-1 imaging using high-resolution quantitative susceptibility mapping (QSM) combined with histogram analysis can improve the diagnostic accuracy in early-stage idiopathic Parkinson's disease (IPD) patients. METHODS: Three-dimensional multiecho gradient-recalled echo images (0.5×0.5×1.0 mm³) were obtained at 3 T for QSM in 38 patients with IPD and 25 healthy subjects. To segment the substantia nigra (SN), regions of interest (ROIs) were semiautomatically drawn at the location below the red nucleus, and the normal-appearing nigrosome-1 was determined by manual correction...
January 2018: Journal of Clinical Neurology
https://www.readbyqxmd.com/read/29603826/seed-point-discontinuity-based-segmentation-method-for-the-substantia-nigra-and-the-red-nucleus-in-quantitative-susceptibility-maps
#15
Tian Guo, Yang Song, Jianqi Li, Mingxia Fan, Xu Yan, Andi He, Dongya Huang, Chaomin Shen, Guixu Zhang, Guang Yang
BACKGROUND: The automatic segmentation of cerebral nuclei in the quantitative susceptibility mapping (QSM) images can provide assistance for surgical treatment and pathological mechanism studies. However, as the most frequently used segmentation method, the atlas method provides unsatisfactory results when segmenting the substantia nigra (SN) and the red nucleus (RN). PURPOSE: To propose and evaluate an improved automatic method based on seed points-discontinuity for segmentations of the SN and the RN in QSM images...
March 31, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29575047/assessment-of-mr-based-r2-and-quantitative-susceptibility-mapping-for-the-quantification-of-liver-iron-concentration-in-a-mouse-model-at-7t
#16
Gregory Simchick, Zhi Liu, Tamas Nagy, May Xiong, Qun Zhao
PURPOSE: To assess the feasibility of quantifying liver iron concentration (LIC) using R2* and quantitative susceptibility mapping (QSM) at a high field strength of 7 Tesla (T). METHODS: Five different concentrations of Fe-dextran were injected into 12 mice to produce various degrees of liver iron overload. After mice were sacrificed, blood and liver samples were harvested. Ferritin enzyme-linked immunosorbent assay (ELISA) and inductively coupled plasma mass spectrometry were performed to quantify serum ferritin concentration and LIC...
March 25, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29573246/non-motor-symptom-burdens-are-not-associated-with-iron-accumulation-in-early-parkinson-s-disease-a-quantitative-susceptibility-mapping-study
#17
Chaewon Shin, Seon Lee, Jee Young Lee, Jung Hyo Rhim, Sun Won Park
BACKGROUND: Quantitative susceptibility mapping (QSM) has been used to measure iron accumulation in the deep nuclei of patients with Parkinson's disease (PD). This study examined the relationship between non-motor symptoms (NMSs) and iron accumulation in the deep nuclei of patients with PD. METHODS: The QSM data were acquired from 3-Tesla magnetic resonance imaging (MRI) in 29 patients with early PD and 19 normal controls. The Korean version of the NMS scale (K-NMSS) was used for evaluation of NMSs in patients...
March 26, 2018: Journal of Korean Medical Science
https://www.readbyqxmd.com/read/29566449/quantitative-susceptibility-mapping-qsm-minimizes-interference-from-cellular-pathology-in-r2-estimation-of-liver-iron-concentration
#18
Jianqi Li, Huimin Lin, Tian Liu, Zhuwei Zhang, Martin R Prince, Kelly Gillen, Xu Yan, Qi Song, Ting Hua, Xiance Zhao, Miao Zhang, Yu Zhao, Gaiying Li, Guangyu Tang, Guang Yang, Gary M Brittenham, Yi Wang
BACKGROUND: A challenge for R2 and R2* methods in measuring liver iron concentration (LIC) is that fibrosis, fat, and other hepatic cellular pathology contribute to R2 and R2* and interfere with LIC estimation. PURPOSE: To examine the interfering effects of fibrosis, fat, and other lesions on R2* LIC estimation and to use quantitative susceptibility mapping (QSM) to reduce these distortions. STUDY TYPE: Prospective. PHANTOMS, SUBJECTS: Water phantoms with various concentrations of gadolinium (Gd), collagen (Cl, modeling fibrosis), and fat; nine healthy controls with no known hepatic disease, nine patients with known or suspected hepatic iron overload, and nine patients with focal liver lesions...
March 22, 2018: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/29548847/simultaneous-quantitative-susceptibility-mapping-and-flutemetamol-pet-suggests-local-correlation-of-iron-and-%C3%AE-amyloid-as-an-indicator-of-cognitive-performance-at-high-age
#19
J M G van Bergen, X Li, F C Quevenco, A F Gietl, V Treyer, R Meyer, A Buck, P A Kaufmann, R M Nitsch, P C M van Zijl, C Hock, P G Unschuld
The accumulation of β-amyloid plaques is a hallmark of Alzheimer's disease (AD), and recently published data suggest that increased brain iron burden may reflect pathologies that synergistically contribute to the development of cognitive dysfunction. While preclinical disease stages are considered most promising for therapeutic intervention, the link between emerging AD-pathology and earliest clinical symptoms remains largely unclear. In the current study we therefore investigated local correlations between iron and β-amyloid plaques, and their possible association with cognitive performance in healthy older adults...
July 1, 2018: NeuroImage
https://www.readbyqxmd.com/read/29547080/evaluation-of-oxygen-extraction-fraction-in-systemic-lupus-erythematosus-patients-using-quantitative-susceptibility-mapping
#20
Mari Miyata, Shingo Kakeda, Kohsuke Kudo, Shigeru Iwata, Yoshiya Tanaka, Yi Wang, Yukunori Korogi
The purposes of this study are to assess the oxygen extraction fraction (OEF) changes on MRI-based quantitative susceptibility mapping (QSM) in systemic lupus erythematosus (SLE) patients and to determine whether QSM-OEF is associated with disease activity in SLE. We enrolled 42 SLE patients and 20 healthy subjects (HS) who had no pathologies on conventional brain MRI. Disease activity was assessed using SLE Disease Activity Index (SLEDAI). For the measurement of QSM-OEF, QSM data were analysed using the Perfusion Mismatch Analyzer software program...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
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