Optimization of Coil Element Configurations for a Matrix Gradient Coil

2018 ◽  
Vol 37 (1) ◽  
pp. 284-292 ◽  
Author(s):  
Stefan Kroboth ◽  
Kelvin J. Layton ◽  
Feng Jia ◽  
Sebastian Littin ◽  
Huijun Yu ◽  
...  
Keyword(s):  
Gradient Coil ◽  
Coil Element

scholarly journals Design of a shielded coil element of a matrix gradient coil

2017 ◽  
Vol 281 ◽  
pp. 217-228 ◽  
Author(s):  
Feng Jia ◽  
Sebastian Littin ◽  
Kelvin J. Layton ◽  
Stefan Kroboth ◽  
Huijun Yu ◽  
...  
Keyword(s):  
Gradient Coil ◽  
Coil Element

scholarly journals Model forB1Imaging in MRI Using the Rotating RF Field

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Adnan Trakic ◽  
Jin Jin ◽  
Ewald Weber ◽  
Stuart Crozier
Keyword(s):  
Degrees Of Freedom ◽  
Acoustic Noise ◽  
Bloch Equation ◽  
Gradient Coil ◽  
Imaging Method ◽  
Nonuniform Field ◽  
Rf Coil ◽  
Image Encoding ◽  
Magnetic Resonance Imaging Mri ◽  
Space Requirements

Conventionally, magnetic resonance imaging (MRI) is performed by pulsing gradient coils, which invariably leads to strong acoustic noise, patient safety concerns due to induced currents, and costly power/space requirements. This modeling study investigates a new silent, gradient coil-free MR imaging method, in which a radiofrequency (RF) coil and its nonuniform field (B1+) are mechanically rotated about the patient. The advantage of the rotatingB1+field is that, for the first time, it provides a large number of degrees of freedom to aid a successfulB1+image encoding process. The mathematical modeling was performed using flip angle modulation as part of a finite-difference-based Bloch equation solver. Preliminary results suggest that representative MR images with intensity deviations of <5% from the original image can be obtained using rotating RF field approach. This method may open up new avenues towards anatomical and functional imaging in medicine.

3-D FEM Analysis of Residual Magnetism Produced by x-Gradient Coil of Permanent Magnet Type of MRI

2007 ◽  
Vol 43 (4) ◽  
pp. 1809-1812 ◽  
Author(s):  
Norio Takahashi ◽  
Atsushi Muraoka ◽  
Daisuke Miyagi ◽  
Koji Miyata ◽  
Ken Ohashi
Keyword(s):  
Permanent Magnet ◽  
Fem Analysis ◽  
Gradient Coil ◽  
Residual Magnetism

A Method for Reducing Secondary Field Effects in Asymmetric MRI Gradient Coil Design

2016 ◽  
Vol 63 (5) ◽  
pp. 924-932 ◽  
Author(s):  
Elliot Smith ◽  
Fabio Freschi ◽  
Maurizio Repetto ◽  
Stuart Crozier
Keyword(s):  
Gradient Coil ◽  
Coil Design ◽  
Secondary Field ◽  
Field Effects ◽  
Gradient Coil Design

Snapshot echo-planar imaging methods: current trends and future perspectives

1990 ◽  
Vol 333 (1632) ◽  
pp. 495-506 ◽  
Keyword(s):  
Magnetic Field ◽  
Echo Planar Imaging ◽  
Gradient Coil ◽  
Future Perspectives ◽  
Planar Imaging ◽  
Pixel Resolution ◽  
Matrix Size ◽  
Imaging Methods ◽  
Echo Planar ◽  
Gradient Coil Design

Ultra-high-speed imaging methods have gained in credibility over the past two years by virtue of improvements in imaging quality. This has come about by increases in both signal:noise ratios and image matrix size. Signal:noise improvements have been gained largely by use of higher magnetic field strengths. In echo-planar imaging (EP1) the image matrix size, and hence pixel resolution, depends on the use of large rapidly switched magnetic field gradients. Improvements in gradient coil design, the introduction of active magnetic screening of the coils and the availability of more powerful amplifiers, have all helped to achieve higher in-plane resolution. On our home-built system, operating at 0.5 T, the pixel resolution is currently 3 x 1.5 mm 2 for a slice thickness of ca . 10 mm. The principles of EP1 are briefly outlined and results of current techniques presented. Future perspectives will be directed to combinations of EP1 with spectroscopy and new developments in echo-volumar imaging.

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