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Magnetic susceptibility anisotropy: Cylindrical symmetry from macroscopically ordered anisotropic molecules and accuracy of MRI measurements using few orientations

Cynthia Wisnieff, Tian Liu, Pascal Spincemaille, Shuai Wang, Dong Zhou, Yi Wang
2013 NeuroImage  
symmetry in susceptibility anisotropy and cylindrical symmetry is a natural outcome of an ordered molecular arrangement.  ...  Recent MRI studies have explored the unique anisotropic magnetic properties of white matter using susceptibility tensor imaging.  ...  Cylindrical symmetry can be used to improve the condition of estimating the susceptibility tensor, CSST, from MRI acquired with few subject orientations.  ... 
doi:10.1016/j.neuroimage.2012.12.050 pmid:23296181 pmcid:PMC3580080 fatcat:skj6eyxdrjaqlomo43jbeveina

A torque balance measurement of anisotropy of the magnetic susceptibility in white matter

Peter van Gelderen, Hendrik Mandelkow, Jacco A. de Zwart, Jeff H. Duyn
2014 Magnetic Resonance in Medicine  
Conclusion-The independently determined anisotropy values confirm estimates inferred from MRI experiments and validate the use of anisotropy to extract novel information about brain fiber structure and  ...  To quantify the effect, excised spinal cord samples were placed in a torque balance inside the magnet of a 7 T MRI system and the magnetic torque was measured as function of orientation.  ...  Quantitative comparison with anisotropy inferred from MRI Analysis of macroscopic field effects observed in MRI in and around major fiber bundles of mouse and human brain have suggested a WM anisotropy  ... 
doi:10.1002/mrm.25524 pmid:25399830 pmcid:PMC4431960 fatcat:liox3cmixvflhkbf2sthnsfruy

Mapping magnetic susceptibility anisotropies of white matter in vivo in the human brain at 7T

Xu Li, Deepti S. Vikram, Issel Anne L. Lim, Craig K. Jones, Jonathan A.D. Farrell, Peter C.M. van Zijl
2012 NeuroImage  
Assuming cylindrical symmetry of the susceptibility tensor in myelinated white matter fibers, we propose a simplified method to reconstruct the susceptibility tensor in terms of a mean magnetic susceptibility  ...  , MMS = (χ ∥ + 2χ ⊥ )/3 and a magnetic susceptibility anisotropy, MSA = χ ∥ − χ ⊥ , where χ ∥ and χ ⊥ are susceptibility parallel and perpendicular to the white matter fiber direction, respectively.  ...  Andreia Faria for her assistance with the determination of susceptibility values using white matter region from the DTI brain atlas. Dr. Peter van Zijl is a paid lecturer for  ... 
doi:10.1016/j.neuroimage.2012.04.042 pmid:22561358 pmcid:PMC3392309 fatcat:kqhkjiloifbbvhzilnh7xb67ry

Comparison of Magnetic Susceptibility Tensor and Diffusion Tensor of the Brain

Wei Li, Chunlei Liu
2013 Journal of Neuroscience and Neuroengineering  
Using mouse brain ex vivo, we compared STI with diffusion tensor imaging (DTI), in terms of tensor values, principal tensor values, anisotropy values, and tensor orientations.  ...  Despite the completely different biophysical underpinnings, magnetic susceptibility tensors and diffusion tensors show many similarities in the tensor and principal tensor images, for example, the tensors  ...  Acknowledgments The study was supported in part by the National Institutes of Health (NIH) through grant R01 MH096979 to C. L and NIBIB P41 EB015897 to Duke Center for In Vivo Microscopy.  ... 
doi:10.1166/jnsne.2013.1075 pmid:25401058 pmcid:PMC4230339 fatcat:urdgbn4rzffu7aglwkzpfmfbhq

Susceptibility tensor imaging (STI) of the brain

Wei Li, Chunlei Liu, Timothy Q. Duong, Peter C. M. van Zijl, Xu Li
2016 NMR in Biomedicine  
Mechanistically, MRI-observed susceptibility anisotropy is mainly attributed to the highly ordered lipid molecules in myelin sheath.  ...  Susceptibility tensor imaging (STI) is a recently developed MRI technique that allows quantitative determination of orientation-independent magnetic susceptibility parameters from the dependence of gradient  ...  Acknowledgement This work was supported in part by the National Institutes of Health (NIH) through grants R01 MH096979 and R01NS079653 to CL and P41 EB015909 to PvZ, a Research Grant from the William &  ... 
doi:10.1002/nbm.3540 pmid:27120169 pmcid:PMC5083244 fatcat:oaye4p5ekrcl3dyww7ljlllcv4

Multidisciplinary Approaches to Multivalued Data: Modeling, Visualization, Analysis (Dagstuhl Seminar 16142)

Ingrid Hotz, Evren Özarslan, Thomas Schultz, Marc Herbstritt
2016 Dagstuhl Reports  
Modelling multivalued data using tensors and higher-order descriptors has become common practice in neuroscience, engineering, and medicine.  ...  Novel tools for image analysis, visualization, as well as statistical hypothesis testing and machine learning are required to extract value from such data, and can only be developed within multidisciplinary  ...  Fewer than six orientations are also feasible by incorporating fiber orientation estimated by diffusion tensor imaging (DTI) and assuming cylindrical symmetry of the susceptibility tensor.  ... 
doi:10.4230/dagrep.6.4.16 dblp:journals/dagstuhl-reports/HotzO016 fatcat:tlx6mmmairgfpgs4mx7dndy5n4

High-speed tensor tomography: iterative reconstruction tensor tomography (IRTT) algorithm

Zirui Gao, Manuel Guizar-Sicairos, Viviane Lutz-Bueno, Aileen Schröter, Marianne Liebi, Markus Rudin, Marios Georgiadis
2019 Acta Crystallographica Section A: Foundations and Advances  
Yet, for identical data sets and computer hardware used, IRTT was shown to be more than an order of magnitude faster.  ...  tensor approximation adequately captures the level of anisotropy and the dominant orientation within a voxel.  ...  Acknowledgements The authors wish to acknowledge Dr Oliver Bunk from the Paul Scherrer Institute, Switzerland, for valuable discussions, and Dr Giovanna Ielacqua from the Institute for Biomedical Engineering  ... 
doi:10.1107/s2053273318017394 fatcat:2rj54utzfnezlddppuf5pzrkly

Ultrasound elastic tensor imaging: comparison with MR diffusion tensor imaging in the myocardium

Wei-Ning Lee, Benoît Larrat, Mathieu Pernot, Mickaël Tanter
2012 Physics in Medicine and Biology  
The authors would like to thank Abdelhak Souilah for designing and fabricating the MR-compatible animal specimen apparatus.  ...  Acknowledgments This study was supported by the Agence Nationale de la Recherche (ANR), the Société Française de Cardiologie (SFC), and the Fédération Française de Cardiologie (FFC).  ...  Fractional anisotropy In order to evaluate the degree of anisotropy in the myocardium, FA was computed.  ... 
doi:10.1088/0031-9155/57/16/5075 pmid:22836727 fatcat:u2arj7gl2rgetjhvc5mxofceye

Modelling the magnetic signature of neuronal tissue

K.B. Blagoev, B. Mihaila, B.J. Travis, L.B. Alexandrov, A.R. Bishop, D. Ranken, S. Posse, C. Gasparovic, A. Mayer, C.J. Aine, I. Ulbert, M. Morita (+3 others)
2007 NeuroImage  
for understanding the possible contrast mechanism underlying the use of MRI to detect and locate these currents.  ...  An unexpected finding of this work is that the cortical orientation with respect to the external magnetic field has little effect on the predicted MRI contrast.  ...  Supported by LANL-LDRD and NS44623.  ... 
doi:10.1016/j.neuroimage.2007.04.033 pmid:17544300 fatcat:kgqdteikcjbsvoht43emmmk24q

Probing Tissue Microstructure Using Susceptibility Contrast Magnetic Resonance Imaging Probing Tissue Microstructure Using Susceptibility Contrast Magnetic Resonance Imaging

Russell Dibb, G Allan, Johnson, Craig, Jeffrey Petrella, Russell Dibb, G Allan, Johnson, Craig Henriquez, Jeffrey, Petrella, Gregg Trahey (+1 others)
2016 unpublished
Intact mouse heart specimens were scanned using MRI at 9.4 T to ascertain both the magnetic susceptibility and myofiber orientation of the tissue.  ...  measurable by MRI, and are potentially the chief sources of the experimentally observed anisotropy. v The growing use of paramagnetic contrast agents in magnetic susceptibility imaging motivated a series  ...  If these molecules are spatially arranged in an ordered fashion within a tissue, then they collectively will exhibit a macroscopic, or bulk, anisotropic susceptibility (Δχ).  ... 

Transverse NMR relaxation in biological tissues

Valerij G. Kiselev, Dmitry S. Novikov
2018 NeuroImage  
Biophysically, transverse relaxation originates from a number of distinct scales -molecular (nanometers), cellular (micrometers), and macroscopic (millimeterlevel MRI resolution).  ...  at the mesoscopic, or intermediate scale (in between the atomic/ molecular scale, and the macroscopic sample/voxel size) affects a macroscopic measurement, as reviewed recently .  ...  Acknowledgments It is a pleasure to thank Pippa Storey for useful discussions, and Laura-Adela Harsan for providing cell image in Fig. 1 . DN was supported in part by NIH/NINDS grant R01 NS088040.  ... 
doi:10.1016/j.neuroimage.2018.06.002 pmid:29885485 pmcid:PMC6175675 fatcat:o6y2phlzxzacffihulmb52ggku

Diffusion lung imaging with hyperpolarized gas MRI

Dmitriy A. Yablonskiy, Alexander L. Sukstanskii, James D. Quirk
2015 NMR in Biomedicine  
This approach, called in vivo lung morphometry, allows from a less than 15-second MRI scan, providing quantitative values and spatial distributions of the same physiological parameters as are measured  ...  Lung imaging using conventional 1 H MRI presents great challenges due to low density of lung tissue, lung motion and very fast lung tissue transverse relaxation (typical T2* is about 1-2 ms).  ...  Acknowledgement We would like to acknowledge helpful discussions and long and productive collaboration with Drs.  ... 
doi:10.1002/nbm.3448 pmid:26676342 pmcid:PMC4911335 fatcat:zozuygsvt5b63kd3jzy43v4nua

Dynamics of wave fronts and filaments in anisotropic cardiac tissue [article]

Hans J.F.M. Dierckx
2015 arXiv   pre-print
In this thesis, a curved-space approach is used to mathematically capture anisotropy of wave propagation.  ...  We derive for the first time the covariant laws of motion for traveling wave fronts and scroll wave filaments in anisotropic excitable media such as cardiac tissue.  ...  Physical principles of diffusion MRI Magnetic Resonance Imaging in a nutshell Up to now, the technique of magnetic resonance imaging (MRI) is one of the few fields where quantum physics has invoked a  ... 
arXiv:1511.03685v1 fatcat:atzrzq3fkffdvdcaxezfj3uxyu

The biological effects of static magnetic fields

1992 American Journal of Orthodontics and Dentofacial Orthopedics  
For For molecules molecules with with cylindrical cylindrical symmetry. symmetry. odd odd terms terms in in n n vanish. vanish.  ...  ., and and Mater, Mater, G., G., Fibrinogen Fibrinogen and and fibrin fibrin structure structure and and fibrin fibrin formallon formallon measured measured by by using using magnetic magnetic orientation  ... 
doi:10.1016/s0889-5406(05)81244-2 fatcat:dzusgut6nffk7kwqttv4dwaaym

Mobile single-sided NMR

B. Blümich, J. Perlo, F. Casanova
2008 Progress in nuclear magnetic resonance spectroscopy  
Weak dipolar couplings of a few Hertz from molecules partially oriented in anisotropic environments are an invaluable source in structural analysis of bio-molecules [318] .  ...  (19) to extract the isotropic and anisotropic relaxation rates, using a Gaussian distribution P(h) of average chain orientations with a variance of 10° [549] .  ... 
doi:10.1016/j.pnmrs.2007.10.002 fatcat:ai3bptqx7rd2vajddpzgnu6qla
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