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Multiple echo multi‐shot diffusion sequence
Author(s) -
Chabert Steren,
Galindo César,
Tejos Cristian,
Uribe Sergio A.
Publication year - 2014
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24244
Subject(s) - echo (communications protocol) , diffusion , single shot , shot (pellet) , sequence (biology) , computer science , measure (data warehouse) , thermal diffusivity , relaxation (psychology) , nuclear magnetic resonance , algorithm , mathematics , physics , materials science , chemistry , optics , medicine , data mining , computer network , biochemistry , quantum mechanics , metallurgy , thermodynamics
Purpose To measure both transversal relaxation time (T 2 ) and diffusion coefficients within a single scan using a multi‐shot approach. Both measurements have drawn interest in many applications, especially in skeletal muscle studies, which have short T2 values. Multiple echo single‐shot schemes have been proposed to obtain those variables simultaneously within a single scan, resulting in a reduction of the scanning time. However, one problem with those approaches is the associated long echo read‐out. Consequently, the minimum achievable echo time tends to be long, limiting the application of these sequences to tissues with relatively long T 2 . Materials and Methods To address this problem, we propose to extend the multi‐echo sequences using a multi‐shot approach, so that to allow shorter echo times. A multi‐shot dual‐echo EPI sequence with diffusion gradients and echo navigators was modified to include independent diffusion gradients in any of the two echoes. Results The multi‐shot approach allows us to drastically reduce echo times. Results showed a good agreement for the T 2 and mean diffusivity measurements with gold standard sequences in phantoms and in vivo data of calf muscles from healthy volunteers. Conclusion A fast and accurate method is proposed to measure T 2 and diffusion coefficients simultaneously, tested in vitro and in healthy volunteers. J. Magn. Reson. Imaging 2014;39:1027–1032. © 2013 Wiley Periodicals, Inc .