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Determination of optimal angles for variable nutation proton magnetic spin‐lattice, T 1 , and spin‐spin, T 2 , relaxation times measurement
Author(s) -
Deoni Sean C.L.,
Peters Terry M.,
Rutt Brian K.
Publication year - 2004
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.10661
Subject(s) - nutation , steady state free precession imaging , physics , nuclear magnetic resonance , spin (aerodynamics) , precession , weighting , relaxation (psychology) , range (aeronautics) , computational physics , condensed matter physics , materials science , magnetic resonance imaging , quantum mechanics , thermodynamics , composite material , medicine , psychology , social psychology , acoustics , radiology
T 1 and T 2 can be rapidly determined with a combination of multiangle spoiled gradient recalled echo (SPGR) and steady‐state free precession (SSFP) imaging. Previously, we demonstrated a simple method for determining the set of SPGR and SSFP angles that provided greater T 1 and T 2 precision than a set of uniformly spaced angles. In this article a more rigorous approach for determining angles is described. Weighted least‐squares is also introduced for T 1 and T 2 estimation and a novel weighting function described. This new approach, suited for imaging applications where large T 1 and T 2 ranges are anticipated, provides high and uniform precision over a wide range of T 1 and T 2 values. Magn Reson Med 51:194–199, 2004. © 2003 Wiley‐Liss, Inc.