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An Active Transmit/Receive NMR Magnetometer for Field Monitoring in Ultra High Field MRI Scanners

J Handwerker, V Bonehi, M Eschelbach, K Scheffler, M Ortmanns, J Anders
2013 Biomedical Engineering  
Thanks to its transmit-receive (TX/RX) capabilities, the system can be used to monitor the spatio-temporal field evolution during a magnetic resonance imaging (MRI) scan and thereby allows for a correction  ...  We present a miniaturized active nuclear magnetic resonance (NMR) magnetometer consisting of a susceptibility matched field probe and a PCB based RF transceiver.  ...  The ultimate goal of the work is to realize an array of field probes monitoring the magnetic field evolution during MRI scans to compensate for spatial-and time-varying magnetic field imperfections.  ... 
doi:10.1515/bmt-2013-4263 pmid:24042946 fatcat:kjp6yyxmpjeubb4edos7dmqqnu

An industrial design solution for integrating NMR magnetic field sensors into an MRI scanner

Michael Kennedy, Yoojin Lee, Zoltan Nagy
2017 Magnetic Resonance in Medicine  
Methods: An extensive set of steps was required to design a 3D printed solution to install a magnetic field camera into the 8-channel head coil of our Philips 3T MRI scanner.  ...  Key words: industrial design, MRI, magnetic field monitoring, dynamic field camera 3D printing, biomedical engineering, multidisciplinary, 3T 2 ABSTRACT Purpose: Neuroimaging research relies on the skills  ...  Animated illustration of the key steps of the design pipeline for installing the probes, cabling and Tx/Rx electronics around an 8ch MRI head coil.  ... 
doi:10.1002/mrm.27055 pmid:29285786 fatcat:ynvatiwo7ze5xidprwspsn7ovq

W(h)ither human cardiac and body magnetic resonance at ultrahigh fields? technical advances, practical considerations, applications, and clinical opportunities

Thoralf Niendorf, Katharina Paul, Celal Oezerdem, Andreas Graessl, Sabrina Klix, Till Huelnhagen, Fabian Hezel, Jan Rieger, Helmar Waiczies, Jens Frahm, Armin M. Nagel, Eva Oberacker (+1 others)
2015 NMR in Biomedicine  
Examples of UHF cardiac and body imaging strategies are demonstrated. Their added value over the kindred counterparts at lower fields is explored along with an outline of research promises.  ...  The achievements of ultrahigh field cardiac and body magnetic resonance are shown to be a powerful motivator and enabler, since the extra speed, signal and imaging capabilities may be invested to overcome  ...  Acknowledgements The authors wish to acknowledge the members of the Berlin Ultrahigh Field Facility  ... 
doi:10.1002/nbm.3268 pmid:25706103 fatcat:t3yfp526tnbrlncrutk5yroy5e

Mobile single-sided NMR

B. Blümich, J. Perlo, F. Casanova
2008 Progress in nuclear magnetic resonance spectroscopy  
TX / RX δ/2 t /2 E t /2 E b G G c G a y x x t /2 E Δ d e f y x x Δ Δ time x y x x x x y Δ t /2 E =δ =δ t /2 E =δ t /2 E =δ t /2 E =δ t /2 E =δ x t =2Δ E y x x x x x δ δ x δ/2 Δ TX/RX G 0 TX/RX In either  ...  (e) Drawing of an MRI scanner for identifying the fibre positions in an air spring bellows for on-line quality control [243] . (f) Depth resolution by the MOUSE Refined for imaging (MRI) [244] .  ... 
doi:10.1016/j.pnmrs.2007.10.002 fatcat:ai3bptqx7rd2vajddpzgnu6qla

A Review of the Principles and Applications of the NMR Technique for Near-Surface Characterization

Ahmad A. Behroozmand, Kristina Keating, Esben Auken
2014 Surveys in geophysics  
This paper presents a comprehensive review of the recent advances in nuclear magnetic resonance (NMR) measurements for near-surface characterization using laboratory, borehole, and field technologies.  ...  These recommendations include improving the signal-tonoise ratio, reducing the effective measurement dead time, and improving production rate of surface NMR (SNMR), reducing the minimum echo time of borehole  ...  Develop NMR relaxation time measurements to monitor contaminant remediation.  ... 
doi:10.1007/s10712-014-9304-0 fatcat:jap34tg6pnexfbnz7j5k2bc3ja

Track I

2014 Biomedical Engineering  
The assessment of the cellularity in bone marrow is an essential step in diagnostic processes in pathology.  ...  The main goal of this paper is to examine echo state networks (ESN) for quantitative cell recognition.  ...  Acknowledgements The specifications for the selection field coil are provided by Gael Bringout (Institute of Medical Engineering, Universität zu Lübeck). We would like to thank Prof. Dr. med.  ... 
doi:10.1515/bmt-2014-5008 pmid:25385893 fatcat:4o7vqkhdmfgk5fjzqpeh74x5te

Novel MRI Technologies for Structural and Functional Imaging of Tissues with Ultra-short T2 Values

Ali Caglar Özen
The goals of this thesis are to evaluate state-of-the-art methods for MRI of tissue with short relaxation times, to prove the feasibility of CEA in a clinical MRI system, and to introduce a new electrophysiological  ...  Conventional MRI has several limitations such as long scan durations, motion artifacts, very high acoustic noise levels, signal loss due to short relaxation times, and RF induced heating of electrically  ...  Tx/Rx Switching In MRI, Tx/Rx resonators are used when there is need for local resonators to increase Tx efficiency.  ... 
doi:10.5445/ir/1000065873 fatcat:hgrbttrqyjdvthonodq46o5lzm

Novel MRI Technologies for Structural and Functional Imaging of Tissues with Ultra-short T₂ Values

Ali Caglar Özen
The goals of this work are to evaluate and improve the state-of-the-art methods for MRI of tissue with short T₂, to prove the feasibility of in vivo Concurrent Excitation and Acquisition, and to introduce  ...  Conventional MRI has several limitations such as long scan durations, motion artifacts, very loud acoustic noise, signal loss due to short relaxation times, and RF induced heating of electrically conducting  ...  Tx/Rx Switching In MRI, Tx/Rx resonators are used when there is need for local resonators to increase Tx efficiency.  ... 
doi:10.5445/ksp/1000068880 fatcat:ya27u7de5zbmdm4kn55lxyaqcq

Improving the image and quantitative data of magnetic resonance imaging through hardware and physics techniques

Joshua D. Kaggie
Following the introduction, five different published and yet unpublished papers for improving the utility of MRI are shown.  ...  Chapter 3 discusses a system using BOLD MRI to measure T2* and invasive fiberoptic probes to measure renal oxygenation (pO2).  ...  BOLD MRI T2* measurements were compared with an invasive oxygen probe for an initial evaluation of the accuracy of renal BOLD MRI.  ... 
doi:10.26053/0h-48tm-s7g0 fatcat:fla6j4esdvhfxlgyg4zp7yiudi

Detailing radio frequency controlled hyperthermia and its application in ultrahigh field magnetic resonance [article]

Lukas Winter, Humboldt-Universität Zu Berlin, Humboldt-Universität Zu Berlin
After demonstrating basic feasibility, theoretical considerations and proof-of-principle experiments were conducted for RF frequencies of up to 1.44GHz to explore electrodynamic constraints for MRI and  ...  The presented work details the basic feasibility of using radiofrequency (RF) fields generated by ultrahigh field (UHF) magnetic resonance (MR) (B0≥7.0T) systems for therapeutic applications such as RF  ...  size and number of TX/RX channels.  ... 
doi:10.18452/17012 fatcat:kgeqnsohnrgllphifw6efzlgkq

Enabling RF technology for ultrahigh field MRI: development and application of self-grounded bow-tie dipole antenna [article]

Thomas Wilhelm Eigentler, Technische Universität Berlin, Marc Kraft
Elevating the field strength results in an increased radiofrequency (RF) for signal transmission and reception in MRI (= Larmor frequency, f ≈ 298 MHz at B0 = 7.0 T).  ...  Magnetic resonance imaging (MRI) is an important diagnostic imaging modality free of ionizing radiation.  ...  Conflicts of Interest: Thoralf Niendorf is founder and CEO of MRI.TOOLS GmbH. Shuailin Wang is an employee of Beijing Deepvision Technology Co., Ltd.  ... 
doi:10.14279/depositonce-15359 fatcat:ommjmkwso5canlgvnigurx7piu

ISMRM Best Practices for Safety Testing of Experimental RF Hardware

Nicola De Zanche, Cornelis van den Berg, David Brunner, Joseph Murphy-Boesch, Joseph Rispoli, Gregor Adriany, Nikolai Avdievich, Nicolas Boulant, Wyger Brink, Ryan Brown, Thomas Fiedler, Kyle Gilbert (+14 others)
This document was written by a working group of twenty-six experts who are members of the Safety and Engineering Study Groups of the International Society for Magnetic Resonance in Medicine (ISMRM).  ...  The reader is responsible for assuring, before implementing any of the recommendations below, that the reader is complying with the laws and regulations of the jurisdiction in which the reader is located  ...  Daniel Sodickson (ISMRM president 2017-2018) for supporting this initiative from its inception.  ... 
doi:10.7939/r3-7vpe-x737 fatcat:d4bo2mvjpbg4lbmfsdwjvqrniu

Development and Optimisation of Radial Techniques for Sodium Magnetic Resonance Imaging

Sonia Nielles-Vallespin
12−25 ms) components of the 23 Na NMR signal for total 23 Na content evaluation.  ...  At an acquisition time T acq = 10 min and a nominal resolution ∆x = 4 mm, the signal-to-noise ratio SNR of the in-vivo 23 Na 3D radial images was twofold higher than in standard cartesian GRE MRI (T E  ...  This active detuning can be accomplished by placing PIN diodes in parallel with tuning elements of the coil, and using a DC gating pulse to switch the diodes (Tx/Rx Control, Fig. A.1) .  ... 
doi:10.11588/heidok.00005262 fatcat:omxb5ixgqbbbjdcjwtbzp2is34

Magnetic resonance imaging biomarkers of cancer : with applications in high intensity focused ultrasound treatment evaluation [article]

I Igor Jacobs, K Klaas Nicolaij, GJ Gustav Strijkers
The image is a 3D stereogram; an object is hidden inside the image which appears in 3D only when viewed correctly.  ...  This is a reference to the MRI methods and image analysis techniques that are presented in this thesis, such as the multiparametric MRI analysis and multi-agent tracer-kinetic modeling approach.  ...  This research was performed within the framework of CTMM, the Center for Translational Molecular Medicine (, project VOLTA (grant 05T-201).  ... 
doi:10.6100/ir793505 fatcat:2ciigggsajdjpnb5yaioi3om3a

Quantitative MR Imaging of the Electric Properties and Local SAR based on Improved RF Transmit Field Mapping

Tobias Voigt
and for thoroughly revising all the analytical calculations, and Kay Nehrke for his valuable support on field mapping.  ...  iv Preface to Christian Stehning for teaching me many practical and important tweaks regarding the scanner operation, Christian Findeklee for providing and explaining the simulation tools and coil models  ...  Both cylinders with dielectric properties (σ A = 0.42 S /m, ε A = 50) and (σ B = 1.35 S /m, ε B = 75) were placed in a Tx/Rx head coil with a feethead offset of 1 cm.  ... 
doi:10.5445/ksp/1000020953 fatcat:y4lxt77jejgjrhepdpibnmzpa4
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