scholarly journals Recent Progress in Birdcage RF Coil Technology for MRI System

Diagnostics ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1017
Author(s):  
Sheikh Faisal Ahmad ◽  
Young Cheol Kim ◽  
Ick Chang Choi ◽  
Hyun Deok Kim
Keyword(s):  
Magnetic Resonance ◽  
Recent Progress ◽  
3D Structure ◽  
Larmor Frequency ◽  
High Sensitivity ◽  
Transverse Magnetic ◽  
Rf Coil ◽  
Low Field ◽  
Volume Of Interest ◽  
Magnetic Resonance Imaging Mri

The radio frequency (RF) coil is one of the key components of the magnetic resonance imaging (MRI) system. It has a significant impact on the performance of the nuclear magnetic resonance (NMR) detection. Among numerous practical designs of RF coils for NMR imaging, the birdcage RF coil is the most popular choice from low field to ultra-high field MRI systems. In the transmission mode, it can establish a strong and homogeneous transverse magnetic field B1 for any element at its Larmor frequency. Similarly, in the reception mode, it exhibits extremely high sensitivity for the detection of even faint NMR signals from the volume of interest. Despite the sophisticated 3D structure of the birdcage coil, the developments in the design, analysis, and implementation technologies during the past decade have rendered the development of the birdcage coils quite reasonable. This article provides a detailed review of the recent progress in the birdcage RF coil technology for the MRI system.

scholarly journals Effectiveness of low-field magnetic resonance imaging in diagnosing brachial plexus tumours in dogs – short communication

2015 ◽  
Vol 59 (2) ◽  
pp. 317-319
Author(s):  
Zbigniew Adamiak ◽  
Yauheni Zhalniarovich ◽  
Paulina Przyborowska ◽  
Joanna Głodek ◽  
Adam Przeworski
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brachial Plexus ◽  
Resonance Imaging ◽  
Gadolinium Contrast ◽  
Gadolinium Contrast Agent ◽  
Low Field ◽  
Mri Sequences ◽  
Magnetic Resonance Imaging Mri ◽  
Brachial Plexus Tumours

AbstractThe aim of the study was to identify magnetic resonance imaging (MRI) sequences that contribute to a quick and reliable diagnosis of brachial plexus tumours in dogs. The tumours were successfully diagnosed in 6 dogs by the MRI with the use of SE, FSE, STIR, Turbo 3 D, 3D HYCE, and GE sequences and the gadolinium contrast agent

Radial magnetic resonance imaging (MRI) using a rotating radiofrequency (RF) coil at 9.4 T

2017 ◽  
Vol 31 (2) ◽  
pp. e3860 ◽  
Author(s):  
Mingyan Li ◽  
Ewald Weber ◽  
Jin Jin ◽  
Thimo Hugger ◽  
Yasvir Tesiram ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Rf Coil ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Mri

Monitoring a typical fermentation process of natto by low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) techniques

2016 ◽  
Vol 8 (39) ◽  
pp. 7135-7140 ◽  
Author(s):  
Jing Wu ◽  
Yanru Li ◽  
Xingsheng Gao
Keyword(s):  
Magnetic Resonance Imaging ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Fermentation Process ◽  
Resonance Imaging ◽  
Low Field ◽  
Magnetic Resonance Imaging Mri ◽  
Lf Nmr ◽  
Nuclear Magnetic

Unique insights into the monitoring of a typical fermentation process of natto based on low field nuclear magnetic resonance (LF-NMR) associated with magnetic resonance imaging (MRI).

FORCE-DETECTED SCANNED PROBE MAGNETIC RESONANCE MICROSCOPY

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3378-3378
Author(s):  
P. C. HAMMEL
Keyword(s):  
Magnetic Resonance ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Atomic Scale ◽  
Magnetic Resonance Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Unique Method ◽  
Magnetic Resonance Imaging Mri ◽  
Non Destructive

Magnetic Resonance Force Microscopy (MRFM) is a novel scanned probe technique that combines the three-dimensional imaging capabilities of magnetic resonance imaging (MRI) with the high sensitivity and resolution of atomic force microscopy (AFM). This emerging technology holds clear potential for resolution at the atomic scale. When fully realized, MRFM will provide a unique method for non-destructive, chemically specifc, subsurface imaging with applicability to a wide variety of materials. I will review results to date spanning applications of MRFM to nuclear spin, electron spin, and ferromagnetic resonance. I will outline the MRFM technique, discuss its present status and indicate future directions of our effort.

Evaluation of Magnetic Resonance Imaging Responsiveness in Active Psoriatic Arthritis at Multiple Timepoints during the First 12 Weeks of Antitumor Necrosis Factor Therapy

2015 ◽  
Vol 43 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Marie Feletar ◽  
Stephen Hall ◽  
Paul Bird
Keyword(s):  
Magnetic Resonance Imaging ◽  
Psoriatic Arthritis ◽  
Magnetic Resonance ◽  
High Field ◽  
Early Response ◽  
Resonance Imaging ◽  
Low Field ◽  
Low Field Mri ◽  
Magnetic Resonance Imaging Mri ◽  
Necrosis Factor

Objective.To assess the responsiveness of high- and low-field extremity magnetic resonance imaging (MRI) variables at multiple timepoints in the first 12 weeks post-antitumor necrosis factor (anti-TNF) therapy initiation in patients with psoriatic arthritis (PsA) and active dactylitis.Methods.Twelve patients with active PsA and clinical evidence of dactylitis involving at least 1 digit were recruited. Patients underwent sequential high-field conventional (1.5 Tesla) and extremity low-field MRI (0.2 Tesla) of the affected hand or foot, pre- and postgadolinium at baseline (pre-TNF), 2 weeks (post-TNF), 6 weeks, and 12 weeks. A blinded observer scored all images on 2 occasions using the PsA MRI scoring system.Results.Eleven patients completed the study, but only 6 patients completed all high-field and low-field MRI assessments. MRI scores demonstrated rapid response to TNF inhibition with score reduction in tenosynovitis, synovitis, and osteitis at 2 weeks. Intraobserver reliability was good to excellent for all variables. High-field MRI demonstrated greater sensitivity to tenosynovitis, synovitis, and osteitis and greater responsiveness to change posttreatment. Treatment responses were maintained to 12 weeks.Conclusion.This study demonstrates the use of MRI in detecting early response to biologic therapy. MRI variables of tenosynovitis, synovitis, and osteitis demonstrated responsiveness posttherapy with high-field scores more responsive to change than low-field scores.

scholarly journals B0-Shimming Methodology for Affordable and Compact Low-Field Magnetic Resonance Imaging Magnets

2021 ◽  
Vol 9 ◽  
Author(s):  
Konstantin Wenzel ◽  
Hazem Alhamwey ◽  
Tom O’Reilly ◽  
Layla Tabea Riemann ◽  
Berk Silemek ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Magnetic Resonance ◽  
Point Of Care ◽  
Low Cost ◽  
Field Measurements ◽  
Target Volume ◽  
Resonance Imaging ◽  
Low Field ◽  
Magnetic Resonance Imaging Mri

Low-field (B0 < 0.2 T) magnetic resonance imaging (MRI) is emerging as a low cost, point-of-care alternative to provide access to diagnostic imaging technology even in resource scarce environments. MRI magnets can be constructed based on permanent neodymium-iron-boron (NdFeB) magnets in discretized arrangements, leading to substantially lower mass and costs. A challenge with these designs is, however, a good B0 field homogeneity, which is needed to produce high quality images free of distortions. In this work, we describe an iterative approach to build a low-field MR magnet based on a B0-shimming methodology using genetic algorithms. The methodology is tested by constructing a small bore (inner bore diameter = 130 mm) desktop MR magnet (<15 kg) at a field strength of B0 = 0.1 T and a target volume of 4 cm in diameter. The configuration consists of a base magnet and shim inserts, which can be placed iteratively without modifying the base magnet assembly and without changing the inner dimensions of the bore or the outer dimensions of the MR magnet. Applying the shims, B0 field inhomogeneity could be reduced by a factor 8 from 5,448 to 682 ppm in the target central slice of the magnet. Further improvements of these results can be achieved in a second or third iteration, using more sensitive magnetic field probes (e.g., nuclear magnetic resonance based magnetic field measurements). The presented methodology is scalable to bigger magnet designs. The MR magnet can be reproduced with off-the-shelf components and a 3D printer and no special tools are needed for construction. All design files and code to reproduce the results will be made available as open source hardware.

scholarly journals Inflammatory and post-inflammatory lesions in the sacroiliac joints and lumbar spine according to magnetic resonance imaging in patients with early axial spondyloarthritis

2019 ◽  
Vol 57 (1) ◽  
pp. 28-32 ◽  
Author(s):  
D. G. Rumyantseva ◽  
Sh. Erdes ◽  
A. V. Smirnov
Keyword(s):  
Magnetic Resonance Imaging ◽  
Lumbar Spine ◽  
Magnetic Resonance ◽  
Disease Duration ◽  
Resonance Imaging ◽  
Sacroiliac Joints ◽  
Low Field ◽  
Low Field Mri ◽  
Magnetic Resonance Imaging Mri ◽  
Inflammatory Changes

Investigation of the evolution of early axial spondylitis (axSP) is now of great importance especially before the appearance of reliable radiological signs of ankylosing spondylitis (AS). Of particular interest is the assessment of inflammatory and post-inflammatory changes in the sacroiliac joints (SJ) and in the spine using magnetic resonance imaging (MRI).The aimof the study was to analyze inflammatory foci in bone according to MRI in the area of SJ and lumbar spine (LS) in patients with early axSP.Material and methods.The study involved the patients of the Moscow cohort CORSAIR (Early Spondyloarthritis Cohort), which was formed in V.A. Nasonova Research Institute of Rheumatology. Low field MRI of SJ and LS was carried out in all patients at inclusion in the study in the T1 and STIR modes.Results and discussion.SJ MRI most often (34.1%) revealed combined foci of inflammation (active and chronic sacroiliitis – SI), 32.9% of patients showed signs of only chronic, rarely – only active SI (19.5%). In a few cases, MRI showed inflammatory changes in LS, which were regarded as active and chronic spondylitis. In patients with a disease duration of up to 1 year, signs of active SI were more common according to MRI than in patients with a longer duration of the disease (30.0 and 14.4%, respectively; p<0.05). All active foci of inflammation (with or without signs of chronic SI) were significantly more frequently detected in patients with AS than in non-radiological axSP (NR-axSP; 61.6% and 44.2%, respectively; p<0.05). The overall incidence of chronic spondylitis (in combination with or without active spondylitis) in patients with AS was higher than in NR-axSP(13.9% and 5.8%, respectively; p<0.05).Conclusion.Patients with AS more often have active lesions at MRI of SJ and chronic ones at MRI of LS than patients with NR-axSP

scholarly journals Current approaches to magnetic resonance imaging diagnosis of epileptogenic and associated lesions of the brain

2018 ◽  
Vol 10 (1S) ◽  
pp. 4-11
Author(s):  
E. M. Perepelova ◽  
V. A. Perepelov ◽  
M. S. Merkulova ◽  
V. E. Sinitsyn
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brain Structure ◽  
Pulse Sequences ◽  
High Sensitivity ◽  
Resonance Imaging ◽  
Functional Changes ◽  
Associated Lesions ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

With the development of current neuroimaging techniques, their role in diagnosing epilepsy is becoming more significant and that is not only in identifying the disease that plays a key role in  epileptogenesis, but also in assisting a clinician in the subsequent  formulation of the diagnosis, in correcting drug therapy, and, in  some cases, in addressing the issue of surgical treatment in the  patient. The priority technique in this case is magnetic resonance  imaging (MRI) that has high sensitivity and specificity in defining the  location of minor and more major lesions of the brain structure  and that includes a set of current sequences that can obtain  important diagnostic information about the functional state of the  brain. This article highlights the International League Against  Epilepsy guidelines for MRI in patients with suspected epilepsy,  assesses the use of and briefly characterizes both structural and  functional pulse sequences that are most commonly included in the  epileptological protocol. It considers major pathological processes  and evaluates anatomical and functional changes in the brain  structure, which play an important role in epileptogenesis.

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