PURPOSE: To assess fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) at three field strengths, regarding signal-to-noise ratio (SNR), contrast and signal homogeneity, in order to determine the potential gain and current challenges of FLAIR at ultra-high field strength (7 T). METHODS: FLAIR images of five healthy volunteers (age 24 +/- 4 years, 4 male) were acquired at 1.5 T, 3 T and 7 T. Image homogeneity and visibility of normal brain structures were evaluated. SNR of grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) were measured in regions not affected by transmit field heterogeneity. RESULTS: The SNR (mean +/- SD) at 7 T (GM 168 +/- 15, WM 125 +/- 11) increased slightly more than proportionally, compared with at 1.5 T (GM 30 +/- 3, WM 22 +/- 2) and 3 T (GM 62 +/- 7, WM 44 +/- 4). Relative contrast between GM and WM at 7 T (1.35 +/- 0.07) was slightly less than at 3 T (1.42 +/- 0.14) or 1.5 T (1.37 +/- 0.07). Several major fibre bundles became visible at 7 T. One incidentally observed white matter lesion was well visible at all field strengths. CONCLUSION: Image homogeneity remains challenging and should be improved by future technical developments. FLAIR imaging at 7 T yields a high SNR,with better contrast for WM substructures and the iron-bearing basal ganglia, and has potential for good conspicuity of WM lesions.
PURPOSE: To assess fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) at three field strengths, regarding signal-to-noise ratio (SNR), contrast and signal homogeneity, in order to determine the potential gain and current challenges of FLAIR at ultra-high field strength (7 T). METHODS: FLAIR images of five healthy volunteers (age 24 +/- 4 years, 4 male) were acquired at 1.5 T, 3 T and 7 T. Image homogeneity and visibility of normal brain structures were evaluated. SNR of grey matter (GM), white matter (WM) and cerebrospinal fluid (CSF) were measured in regions not affected by transmit field heterogeneity. RESULTS: The SNR (mean +/- SD) at 7 T (GM 168 +/- 15, WM 125 +/- 11) increased slightly more than proportionally, compared with at 1.5 T (GM 30 +/- 3, WM 22 +/- 2) and 3 T (GM 62 +/- 7, WM 44 +/- 4). Relative contrast between GM and WM at 7 T (1.35 +/- 0.07) was slightly less than at 3 T (1.42 +/- 0.14) or 1.5 T (1.37 +/- 0.07). Several major fibre bundles became visible at 7 T. One incidentally observed white matter lesion was well visible at all field strengths. CONCLUSION: Image homogeneity remains challenging and should be improved by future technical developments. FLAIR imaging at 7 T yields a high SNR,with better contrast for WM substructures and the iron-bearing basal ganglia, and has potential for good conspicuity of WM lesions.
Authors: E Yacoub; A Shmuel; J Pfeuffer; P F Van De Moortele; G Adriany; P Andersen; J T Vaughan; H Merkle; K Ugurbil; X Hu Journal: Magn Reson Med Date: 2001-04 Impact factor: 4.668
Authors: W Schwindt; H Kugel; R Bachmann; S Kloska; T Allkemper; D Maintz; B Pfleiderer; B Tombach; W Heindel Journal: Eur Radiol Date: 2003-07-05 Impact factor: 5.315
Authors: Jeff H Duyn; Peter van Gelderen; Tie-Qiang Li; Jacco A de Zwart; Alan P Koretsky; Masaki Fukunaga Journal: Proc Natl Acad Sci U S A Date: 2007-06-22 Impact factor: 11.205
Authors: William D Rooney; Glyn Johnson; Xin Li; Eric R Cohen; Seong-Gi Kim; Kamil Ugurbil; Charles S Springer Journal: Magn Reson Med Date: 2007-02 Impact factor: 4.668
Authors: J V Hajnal; B De Coene; P D Lewis; C J Baudouin; F M Cowan; J M Pennock; I R Young; G M Bydder Journal: J Comput Assist Tomogr Date: 1992 Jul-Aug Impact factor: 1.826
Authors: Florent Eggenschwiler; Kieran Robert O'Brien; Daniel Gallichan; Rolf Gruetter; José Pedro Marques Journal: MAGMA Date: 2016-04-08 Impact factor: 2.310
Authors: Adrienne N Dula; Elizabeth M Asche; Bennett A Landman; E Brian Welch; Siddharama Pawate; Subramaniam Sriram; John C Gore; Seth A Smith Journal: Magn Reson Med Date: 2011-03-22 Impact factor: 4.668
Authors: Paul A Nyquist; Murat Bilgel; Rebecca Gottesman; Lisa R Yanek; Taryn F Moy; Lewis C Becker; Jennifer L Cuzzocreo; Jerry Prince; Bruce A Wasserman; David M Yousem; Diane M Becker; Brian G Kral; Dhananjay Vaidya Journal: Neurobiol Aging Date: 2015-01-07 Impact factor: 4.673
Authors: Wolter L de Graaf; Jaco J M Zwanenburg; Fredy Visser; Mike P Wattjes; Petra J W Pouwels; Jeroen J G Geurts; Chris H Polman; Frederik Barkhof; Peter R Luijten; Jonas A Castelijns Journal: Eur Radiol Date: 2011-08-27 Impact factor: 5.315