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Contrast optimization of fluid‐attenuated inversion recovery (flair) imaging
Author(s) -
Rydberg John N.,
Riederer Stephen J.,
Rydberg Charlotte H.,
Jack Clifford R.
Publication year - 1995
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.1910340612
Subject(s) - fluid attenuated inversion recovery , contrast (vision) , nuclear magnetic resonance , multiple sclerosis , magnetic resonance imaging , echo time , nuclear medicine , white matter , materials science , chemistry , physics , medicine , radiology , optics , psychiatry
The optimization of contrast is considered for the fluid‐attenuated inversion recovery (FLAIR) MRI pulse sequence, specifically the contrast of multiple sclerosis (MS) to white matter (WM). A performance bound is identified at 1.5 Tesla as that provided using an inversion time (TI) of 2900 ms. It is shown that TR /TI times exceeding 11000/2600 ms provide about 90% of the MS‐WM contrast possible theoretically. The commonly reported TR /TI combination of 6000/2000 provides only about 60%. For TR times exceeding 8000 ms, an echo time ( TE ) of 140 ms is at or near optimum. Use of TR /TI times less than 9000/2400 lacks efficiency in multisection imaging. Predicted relative contrast performance of TR /TI 11000/2600 versus 6000/2000 was evaluated in seven patients with known MS lesions, and measurements closely matched theoretical predictions. It is strongly recommended that for near optimum contrast and high multisection efficiency, FLAIR should be performed with TR /TI times exceeding 10000/2500 ms.