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Optimized double inversion recovery for reduction of T 1 weighting in fluid‐attenuated inversion recovery
Author(s) -
Madhuranthakam Ananth J.,
Sarkar Subhendra N.,
Busse Reed F.,
Bakshi Rohit,
Alsop David C.
Publication year - 2012
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.22979
Subject(s) - fluid attenuated inversion recovery , multiple sclerosis , weighting , cerebrospinal fluid , nuclear medicine , white matter , magnetic resonance imaging , nuclear magnetic resonance , physics , computer science , medicine , radiology , pathology , psychiatry
Fluid‐attenuated inversion recovery (FLAIR) is a routinely used technique in clinical practice to detect long T 2 lesions by suppressing the cerebrospinal fluid. Concerns remain, however, that the inversion pulse in FLAIR imparts T 1 weighting that can decrease the detectability and mischaracterize some lesions. Hence, FLAIR is usually acquired in conjunction with a standard T 2 to guard against these concerns. Recently, double inversion recovery (DIR) preparations have highlighted certain types of lesions by suppressing both cerebrospinal fluid and white matter but produce even stronger T 1 contrast than FLAIR. This work shows that the inversion times in a DIR sequence can be optimized to minimize unwanted T 1 weighting, enabling the acquisition of cerebrospinal fluid‐suppressed images with pure T 2 weighting. This technique is referred to as T 1 ‐nulled DIR. The theory to determine the optimized inversion times is discussed and the results are shown by simulations, normal volunteer studies, and multiple sclerosis patient studies. T 1 ‐nulled DIR provides equivalent or superior contrast between gray and white matters as well as white matter and multiple sclerosis lesion at the same repetition time. Multiple sclerosis lesions appeared sharper on T 1 ‐nulled DIR compared to FLAIR. T 1 ‐nulled DIR has the potential to replace the combination of standard T 2 and FLAIR acquisitions in many clinical protocols. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.