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Magnetic resonance imaging with adiabatic pulses using a single surface coil for RF transmission and signal detection

 

作者: Michael Garwood,   Kǎmil Uĉurbil,   Alan R. Rath,   M. Robin Bendall,   Brian D. Ross,   Steven L. Mitchell,   Hellmut Merkle,  

 

期刊: Magnetic Resonance in Medicine  (WILEY Available online 1989)
卷期: Volume 9, issue 1  

页码: 25-34

 

ISSN:0740-3194

 

年代: 1989

 

DOI:10.1002/mrm.1910090105

 

出版商: Wiley Subscription Services, Inc., A Wiley Company

 

数据来源: WILEY

 

摘要:

AbstractIn order to overcome the problems that arise from nonuniformB1, 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 ofB1, 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 inB1magnitude. This insensitivity toB1strength enables the execution ofT 1 −and/orT 2 −weighted spin‐echo imaging experiments using coils, such as the surface coil, with extremely inhomogeneousB1profiles. 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‐qualityT 1 −and/orT 2 −weighted images withoutB1, arti

 

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