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Quantitative effects of inclusion of fat on muscle diffusion tensor MRI measurements
Author(s) -
Williams Sarah E.,
Heemskerk Anneriet M.,
Welch E. Brian,
Li Ke,
Damon Bruce M.,
Park Jane H.
Publication year - 2013
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.24045
Subject(s) - fractional anisotropy , diffusion mri , anisotropy , nuclear magnetic resonance , monotonic function , eigenvalues and eigenvectors , diffusion , tensor (intrinsic definition) , mathematics , skeletal muscle , materials science , chemistry , physics , mathematical analysis , magnetic resonance imaging , anatomy , medicine , geometry , thermodynamics , radiology , quantum mechanics
Purpose To determine the minimum water percentage in a muscle region of interest that would allow diffusion tensor (DT−) MRI data to reflect the diffusion properties of pure muscle accurately. Materials and Methods Proton density‐weighted images with and without fat saturation were obtained at the mid‐thigh in four subjects. Co‐registered DT‐MR images were used to calculate the diffusion tensor's eigenvalues and fractional anisotropy. Results The eigenvalues transitioned monotonically as a function of water signal percentage from values near to those expected for pure fat to those for pure muscle. Also, the fractional anisotropy transitioned monotonically from 0.50 (fat) to 0.20 (muscle). For water signal percentages >55%, none of the diffusion indices differed significantly from those for regions of >90% muscle. Conclusion Accounting for the T 1 and T 2 values of muscle and fat and the pulse sequence properties, it is concluded that, as a conservative estimate, regions must contain at least 76% muscle tissue to reflect the diffusion properties of pure muscle accurately. J. Magn. Reson. Imaging 2013;38:1292–1297. © 2013 Wiley Periodicals, Inc.