k‐Space Domain Parallel Transmit Pulse Design

2020 ◽  
Author(s):  
Jun Ma ◽  
Bernhard Gruber ◽  
Xinqiang Yan ◽  
William A. Grissom
Keyword(s):  
Space Domain ◽  
Pulse Design ◽  
Parallel Transmit

scholarly journals Parallel transmit pulse design for patients with deep brain stimulation implants

2014 ◽  
Vol 73 (5) ◽  
pp. 1896-1903 ◽  
Author(s):  
Yigitcan Eryaman ◽  
Bastien Guerin ◽  
Can Akgun ◽  
Joaquin L. Herraiz ◽  
Adrian Martin ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Pulse Design ◽  
Parallel Transmit ◽  
Deep Brain

scholarly journals A Statistical Robust Approach to Design Parallel Transmit Radiofrequency Excitations in MRI

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Vincent Gras ◽  
Franck Mauconduit ◽  
Nicolas Boulant
Keyword(s):  
Performance Metrics ◽  
Magnetic Field Gradient ◽  
Population Sample ◽  
Computation Time ◽  
7 Tesla ◽  
Spin Excitation ◽  
Pulse Design ◽  
Pulse Technique ◽  
Parallel Transmit ◽  
Design Database

In MRI, at ultrahigh field, the use of parallel transmit radiofrequency (RF) arrays is very beneficial to better control spin excitation spatially. In that framework, the so-called “universal pulse” technique, proposed recently for head imaging at 7 tesla, gives access to “plug-and-play” nonadiabatic solutions exhibiting good robustness against intersubject variations in the resonant transmit fields. This new type of solution has been defined so far as the result of numerical pulse optimizations performed across a collection of RF field maps acquired on a small population sample (pulse design database). In this work, we investigate an alternative universal pulse design approach in the linear small tip angle regime whereby the database of RF field maps is first transformed into a second-order statistical model and which then exploits a statistical robust design formalism for the optimization of the RF and magnetic field gradient waveforms. Experimental validation with an eightfold transmit RF coil for 7 tesla brain imaging shows that this new approach brings some benefit in terms of computational efficiency. Hence, for a design database composed of 35 maps, the computation time initially of 50 min could be reduced down to 3 min. The proposed statistical approach thus enables integration of large databases, presumably necessary to ensure robust solutions. Finally, it provides means to compute flip angle statistics and, along with it, simple performance metrics for quality assurance (RF pulse performance) or guidance in the optimization of TX array architectures.

scholarly journals A generalized slab-wise framework for parallel transmit multiband RF pulse design

2015 ◽  
Vol 75 (4) ◽  
pp. 1444-1456 ◽  
Author(s):  
Xiaoping Wu ◽  
Sebastian Schmitter ◽  
Edward J. Auerbach ◽  
Kâmil Uğurbil ◽  
Pierre-François Van de Moortele
Keyword(s):  
Pulse Design ◽  
Parallel Transmit ◽  
Rf Pulse

In vivo demonstration of whole-brain multislice multispoke parallel transmit radiofrequency pulse design in the small and large flip angle regimes at 7 Tesla

2016 ◽  
Vol 78 (3) ◽  
pp. 1009-1019 ◽  
Author(s):  
Vincent Gras ◽  
Alexandre Vignaud ◽  
Alexis Amadon ◽  
Franck Mauconduit ◽  
Denis Le Bihan ◽  
...  
Keyword(s):  
Flip Angle ◽  
7 Tesla ◽  
Whole Brain ◽  
Pulse Design ◽  
Parallel Transmit ◽  
Radiofrequency Pulse

scholarly journals Seven-Tesla Time-of-Flight Angiography Using a 16-Channel Parallel Transmit System With Power-Constrained 3-dimensional Spoke Radiofrequency Pulse Design

2014 ◽  
Vol 49 (5) ◽  
pp. 314-325 ◽  
Author(s):  
Sebastian Schmitter ◽  
Xiaoping Wu ◽  
Edward J. Auerbach ◽  
Gregor Adriany ◽  
Josef Pfeuffer ◽  
...  
Keyword(s):  
Time Of Flight ◽  
Pulse Design ◽  
3 Dimensional ◽  
Parallel Transmit ◽  
Radiofrequency Pulse

scholarly journals Array-compressed parallel transmit pulse design

2015 ◽  
Vol 76 (4) ◽  
pp. 1158-1169 ◽  
Author(s):  
Zhipeng Cao ◽  
Xinqiang Yan ◽  
William A. Grissom
Keyword(s):  
Pulse Design ◽  
Parallel Transmit

Open Localization in Micro LeadFrame Package Using Space Domain Reflectometry

2013 ◽  
Author(s):  
J. Gaudestad ◽  
V. Talanov ◽  
A. Orozco ◽  
M. Marchetti
Keyword(s):  
Magnetic Field ◽  
Radio Frequency ◽  
Standing Wave ◽  
High Resistance ◽  
Space Domain ◽  
The Past ◽  
Open Defects ◽  
Rf Electronics ◽  
Rf Signal ◽  
The Magnetic Field

Abstract In the past couple years, Space Domain Reflectometry (SDR) has become a mainstream method to locate open defects among the major semiconductor manufacturers. SDR injects a radio frequency (RF) signal into the open trace creating a standing wave with a node at the open location. The magnetic field generated by the standing wave is imaged with a SQUID sensor using RF electronics. In this paper, we show that SDR can be used to non-destructively locate high resistance failures in Micro LeadFrame Packages (MLP).

Fault Isolation of Open Defects Using Space Domain Reflectometry

2012 ◽  
Author(s):  
Mayue Xie ◽  
Zhiguo Qian ◽  
Mario Pacheco ◽  
Zhiyong Wang ◽  
Rajen Dias ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Fault Isolation ◽  
Nondestructive Technique ◽  
Space Domain ◽  
New Approach ◽  
Defect Localization ◽  
Open Faults ◽  
Open Defects ◽  
Application Optimization ◽  
Rf Magnetic Field

Abstract Recently, a new approach for isolation of open faults in integrated circuits (ICs) was developed. It is based on mapping the radio-frequency (RF) magnetic field produced by the defective part fed with RF probing current, giving the name to Space Domain Reflectometry (SDR). SDR is a non-contact and nondestructive technique to localize open defects in package substrates, interconnections and semiconductor devices. It provides 2D failure isolation capability with defect localization resolution down to 50 microns. It is also capable of scanning long traces in Si. This paper describes the principles of the SDR and its application for the localization of open and high resistance defects. It then discusses some analysis methods for application optimization, and gives examples of test samples as well as case studies from actual failures.

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