Premium
Compensation for spin‐lock artifacts using an off‐resonance rotary echo in T 1 ρ off ‐weighted imaging
Author(s) -
Witschey Walter R.T.,
Borthakur Arijitt,
Elliott Mark A.,
Mellon Eric,
Niyogi Sampreet,
Wang Chenyang,
Reddy Ravinder
Publication year - 2007
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.21134
Subject(s) - flip angle , spin echo , nuclear magnetic resonance , excitation , pulse sequence , resonance (particle physics) , fast spin echo , physics , magnetic resonance imaging , offset (computer science) , imaging phantom , pulse (music) , optics , atomic physics , computer science , medicine , quantum mechanics , radiology , programming language , detector
The origin of image artifacts in an off‐resonance spin‐locking experiment is shown to be imperfections in the excitation flip angle. A pulse sequence for off‐resonance spin locking is implemented that compensates for imperfections in the excitation flip angle through an off‐resonance rotary echo. The off‐resonance rotary echo alternates the frequency offset and phase of the RF transmitter during two spin‐locking pulses of equal duration. The underlying theory is detailed, and MR images demonstrate the effectiveness of the technique in agarose gel phantoms and in in vivo human brain at 3T. Magn Reson Med 57:2–7, 2007. © 2006 Wiley‐Liss, Inc.