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Magnetic resonance imaging with adiabatic pulses using a single surface coil for RF transmission and signal detection
Author(s) -
Garwood Michael,
Uĉurbil Kǎmil,
Rath Alan R.,
Bendall M. Robin,
Ross Brian D.,
Mitchell Steven L.,
Merkle Hellmut
Publication year - 1989
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910090105
Subject(s) - electromagnetic coil , excitation , perpendicular , adiabatic process , optics , radio frequency , radiofrequency coil , physics , nuclear magnetic resonance , scanner , signal (programming language) , parallel communication , materials science , rf power amplifier , transmitter , acoustics , transmission (telecommunications) , computer science , optoelectronics , telecommunications , mathematics , geometry , quantum mechanics , thermodynamics , programming language , amplifier , channel (broadcasting) , cmos
In order to overcome the problems that arise from nonuniform B 1 , fields, there has been interest in developing pulses that are insensitive to large variations in RF power. Pulses derived from adiabatic passage principles that can execute spin inversion, excitation, and 90°and 180° plane rotations in the presence of B 1 , inhomogeneities have recently been described. When driven with optimized modulation functions, these pulses can execute uniform excitation, refocusing, and slice‐selective inversion over a 10‐fold or greater variation in B 1 magnitude. This insensitivity to B 1 strength enables the execution of T 1 −and/or T 2 −weighted spin‐echo imaging experiments using coils, such as the surface coil, with extremely inhomogeneous B 1 profiles. We have successfully acquired images with these pulses at 200 MHz using a single surface coil as the transmitter and receiver. Images of the slice definition, the region over which the excitation and refocusing pulses operate with a surface coil, and brain images obtained with slice planes perpendicular to the plane of the surface coil are presented. Results demonstrate that these pulses can be transmitted with a surface coil to yield high‐quality T 1 −and/or T 2 −weighted images without B 1 , artifacts. © 1989 Academic Press, Inc.