Journal ArticleDOI
The NMR multi-transmit phased array: a Cartesian feedback approach.
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TLDR
It is shown that, without loss of transmitter efficiency, a high effective impedance may be created in series with each coil in the array by the use of Cartesian negative feedback, which is viable for signal reception and more efficacious than pre-amplifier damping, albeit over a smaller bandwidth.About:
This article is published in Journal of Magnetic Resonance.The article was published on 2004-11-01. It has received 77 citations till now. The article focuses on the topics: Phased array & Electromagnetic coil.read more
Citations
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Journal ArticleDOI
Exploring the limits of RF shimming for high-field MRI of the human head.
TL;DR: Numerical calculations are used to explore the limits of RF shimming in the human head and it is found that a 16‐element array can effectively shim a single slice at frequencies up to 600 MHz and the whole brain at up to 300 MHz.
Journal ArticleDOI
Parallel transmission for ultrahigh‐field imaging
TL;DR: This review discusses the many ways in which parallel transmission provides previously unavailable degrees of freedom that allow full spatial and temporal control of the radiofrequency (RF) fields, ranging from making more uniform transmit fields to the design of subject‐tailored RF pulses for both uniform excitation and spatial selection.
Journal ArticleDOI
Eight-channel transmit/receive body MRI coil at 3T.
Peter Vernickel,Peter Röschmann,Christian Findeklee,K.-M. Lüdeke,Ch. Leussler,J. Overweg,Ulrich Katscher,Ingmar Grässlin,K. Schünemann +8 more
TL;DR: The design of a decoupled eight‐element transmit/receive body coil for 3T is described and the functionality and capabilities of the coil are demonstrated using RF measurements as well as MRI sequences.
Journal ArticleDOI
Degenerate mode band‐pass birdcage coil for accelerated parallel excitation
Vijayanand Alagappan,Vijayanand Alagappan,Juergen Nistler,Elfar Adalsteinsson,Elfar Adalsteinsson,Kawin Setsompop,Ulrich Fontius,Adam C. Zelinski,Markus Vester,Graham Wiggins,Franz Hebrank,Wolfgang Renz,Franz Schmitt,Lawrence L. Wald,Lawrence L. Wald +14 more
TL;DR: An eight‐rung, 3T degenerate birdcage coil was constructed and evaluated for accelerated parallel excitation of the head with eight independent excitation channels and the orthogonal basis set provided by the Butler matrix was found to be advantageous when an Orthogonal subset of these modes was used to mitigate B1 transmit inhomogeneities using parallelexcitation.
Journal ArticleDOI
Self-decoupled radiofrequency coils for magnetic resonance imaging
TL;DR: A novel self-decoupled RF coil design with a simple structure that requires only an intentional redistribution of electrical impedances around the length of the coil loop achieves high inter-coil isolation between adjacent and non-adjacent elements of loops and dipoles.
References
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Journal ArticleDOI
The NMR phased array.
TL;DR: Methods for simultaneously acquiring and subsequently combining data from a multitude of closely positioned NMR receiving coils are described, conceptually similar to phased array radar and ultrasound and hence the techniques are called the “NMR phased array.”
Book
Biomedical magnetic resonance technology
Ching-Nien Chen,D. I. Hoult +1 more
TL;DR: Part 1 Magnetic resonance fundamentals: historical concepts precession and alignment resonance and the rotating frame relaxation and chemical shift phase sensitive detection mathematical treatment problems.
Journal ArticleDOI
Coupling and decoupling theory and its application to the MRI phased array
TL;DR: A new method for decoupling phased‐array coils without overlapping the nearest coil pairs is offered, based on the assumption that any n‐element phased array can be decoupled by a 2n‐port interface system between phased array and preamplifiers.
Journal ArticleDOI
Human magnetic resonance imaging at 8 T.
Pierre Marie L. Robitaille,Amir M. Abduljalil,Alayar Kangarlu,Xiaoliang Zhang,Ying Yu,Richard Burgess,S. Bair,P. Noa,L. Yang,Hui Zhu,Brian S. Palmer,Zongcheng Jiang,D. M. Chakeres,Dimitri G. Spigos +13 more
TL;DR: The first human magnetic resonance image (MRI) obtained at ultrahigh field strengths (8 T) is presented and it is demonstrated that clinical imaging will be possible at 8 T and that reasonable quality head images can be obtained at this field strength.