Cost and Performance of Low Field Magnetic Resonance Imaging

1987 ◽  
Vol 96 ◽  
Author(s):  
Lawrence E. Crooks ◽  
Ching Yao ◽  
Mitsuaki Arakawa ◽  
James D. Hale ◽  
Joseph W. Carlson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Permanent Magnets ◽  
Pulse Sequence ◽  
Low Cost ◽  
Resonance Imaging ◽  
Noise Levels ◽  
Diagnostic Quality ◽  
Low Field ◽  
And Performance

ABSTRACTMagnetic Resonance Imaging technology has advanced on many fronts. Two important areas are the improvement of signal-to-noise levels and the understanding of imaging pulse sequence optimization. Based on these advances, low cost imagers using very low field permanent magnets are providing images of diagnostic quality.

scholarly journals 3D-Spatial encoding with permanent magnets for ultra-low field magnetic resonance imaging

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Michael W. Vogel ◽  
Ruben Pellicer Guridi ◽  
Jiasheng Su ◽  
Viktor Vegh ◽  
David C. Reutens
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Permanent Magnets ◽  
Resonance Imaging ◽  
Spatial Encoding ◽  
Low Field

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.

MAGNETIC RESONANCE IMAGING OF THE CANINE ABDOMEN: EFFECT OF PULSE SEQUENCE ON DIAGNOSTIC QUALITY

2013 ◽  
Vol 54 (3) ◽  
pp. 253-262 ◽  
Author(s):  
Rebecca Manley ◽  
Andrea R. Matthews ◽  
Federica Morandi ◽  
George A. Henry ◽  
Katherine H. DeAnna ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Pulse Sequence ◽  
Resonance Imaging ◽  
Diagnostic Quality

scholarly journals SQUID-Based Magnetic Resonance Imaging at Ultra-Low Field Using the Backprojection Method

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qingqian Guo ◽  
Changyu Ma ◽  
Xin Zhang ◽  
Yajie Xu ◽  
Meisheng Fan ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Quantum Interference ◽  
Pulse Sequence ◽  
Signal To Noise Ratio ◽  
Spin Echo ◽  
Imaging Method ◽  
Resonance Imaging ◽  
Field Range ◽  
Low Field

Ultra-low field magnetic resonance imaging (ULF MRI) is an effective imaging technique that applies the ultrasensitive detector of superconducting quantum interference device (SQUID) sensor to detect the MR signal at a microtesla field range. In this work, we designed and developed a SQUID-based ULF MRI system with a frequency-adjustable measurement field, the performance of which was characterized via water phantoms. In order to enhance the MR signals, a 500 mT Halbach magnet was used to prepolarize the magnetization of the sample prior to excitation. The signal-to-noise-ratio (SNR) of the spin-echo- (SE-) based pulse sequence can reach up to 70 in a single scan. The images were then reconstructed successfully by using the maximum likelihood expectation maximization (MLEM) algorithm based on the backprojection imaging method. It was demonstrated that an in-plane resolution of 1.8 × 1.8 mm2 can be achieved which indicated the feasibility of SQUID-based MRI at the ULF.

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

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