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Double half RF pulses for reduced sensitivity to eddy currents in UTE imaging
Author(s) -
Josan Sonal,
Pauly John M.,
Daniel Bruce L.,
Pauly Kim Butts
Publication year - 2009
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.21879
Subject(s) - eddy current , pulse (music) , sensitivity (control systems) , signal (programming language) , wafer , excitation , nuclear magnetic resonance , selectivity , physics , materials science , optics , chemistry , optoelectronics , computer science , electronic engineering , quantum mechanics , detector , biochemistry , catalysis , programming language , engineering
Ultrashort echo time imaging with half RF pulse excitation is challenging as eddy currents induced by the slice‐select gradient distort the half pulse slice profile. This work presents two pulses with T 2 ‐dependent slice profiles that are less sensitive to eddy currents. The double half pulse improves the slice selectivity for long T 2 components, while the inverted double half pulse suppresses the unwanted long T 2 signal. Thus, both approaches prevent imperfect cancellation of out‐of‐slice signal from contaminating the desired slice. Experimental results demonstrate substantially improved slice selectivity and R 2 * quantitation accuracy with these pulses. These pulses are effective in making short T 2 imaging and quantitation less sensitive to eddy currents and provide an alternative to time‐consuming gradient characterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.