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Accurate multislice gradient echo T 1 measurement in the presence of non‐ideal RF pulse shape and RF field nonuniformity
Author(s) -
Parker Geoffrey J.M.,
Barker Gareth J.,
Tofts Paul S.
Publication year - 2001
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.1112
Subject(s) - multislice , ideal (ethics) , nuclear magnetic resonance , echo (communications protocol) , pulse (music) , physics , field (mathematics) , gradient echo , pulse sequence , optics , materials science , computer science , magnetic resonance imaging , mathematics , medicine , radiology , detector , pure mathematics , philosophy , epistemology , computer network
A methodology is presented for estimating T 1 using a two‐point technique with a standard multislice gradient echo sequence. The method explicitly corrects for the shape of the RF pulse and for spatial variations in transmitted RF field intensity. Including these factors in the calculation of T 1 gives a substantial improvement in accuracy and precision of two‐point gradient echo T 1 measurements in the presence of RF nonuniformity and non‐ideal pulse profiles. The mean accuracy of the technique was found to be 1.4%. The mean precision was found to be 3.0%. The mean variation along the axis of a head coil was found to be 2.3%. Magn Reson Med 45:838–845, 2001. © 2001 Wiley‐Liss, Inc.