TY - JOUR
T1 - Fiber orientation measurements by diffusion tensor imaging improve hydrogen-1 magnetic resonance spectroscopy of intramyocellular lipids in human leg muscles
AU - Valaparla, Sunil K.
AU - Gao, Feng
AU - Daniele, Giuseppe
AU - Abdul-Ghani, Muhammad
AU - Clarke, Geoffrey D
N1 - Publisher Copyright:
© 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Twelve healthy subjects underwent hydrogen-1 magnetic resonance spectroscopy (1H-MRS) acquisition (15 × 15 × 15 mm3), diffusion tensor imaging (DTI) with a b-value of 600 smm-2, and fat-water magnetic resonance imaging (MRI) using the Dixon method. Subject-specific muscle fiber rientation, derived from DTI, was used to estimate the lipid proton spectral chemical shift. Pennation angles were measured as 23.78 deg in vastus lateralis (VL), 17.06 deg in soleus (SO), and 8.49 deg n tibialis anterior (TA) resulting in a chemical shift between extramyocellular lipids (EMCL) and ntramyocellular lipids (IMCL) of 0.15, 0.17, and 0.19 ppm, respectively. IMCL concentrations were .66 ± 1.24 mmol kg-1, 6.12 ± 0.77 mmol kg-1, and 2.33 ± 0.19 mmol kg-1 in SO, VL, and TA, espectively. Significant differences were observed in IMCL and EMCL pairwise comparisons in SO, L, and TA (p ≤ 0.05). Strong correlations were observed between total fat fractions from 1H-MRS and Dixon MRI for VL (r = 0.794), SO (r = 0.655), and TA (r = 0.897). Bland-Altman analysis between at fractions (FFMRS and FFMRI) showed good agreement with small limits of agreement (LoA): bias = - .21% (LoA: -1.12% to 0.69%) in VL, bias = 0.025% (LoA: -1.28% to 1.33%) in SO, and bias = - .13% (LoA: -0.74% to 0.47%) in TA. The results of this study demonstrate the variation in muscle fiber orientation and lipid concentrations in these three skeletal muscle types.
AB - Twelve healthy subjects underwent hydrogen-1 magnetic resonance spectroscopy (1H-MRS) acquisition (15 × 15 × 15 mm3), diffusion tensor imaging (DTI) with a b-value of 600 smm-2, and fat-water magnetic resonance imaging (MRI) using the Dixon method. Subject-specific muscle fiber rientation, derived from DTI, was used to estimate the lipid proton spectral chemical shift. Pennation angles were measured as 23.78 deg in vastus lateralis (VL), 17.06 deg in soleus (SO), and 8.49 deg n tibialis anterior (TA) resulting in a chemical shift between extramyocellular lipids (EMCL) and ntramyocellular lipids (IMCL) of 0.15, 0.17, and 0.19 ppm, respectively. IMCL concentrations were .66 ± 1.24 mmol kg-1, 6.12 ± 0.77 mmol kg-1, and 2.33 ± 0.19 mmol kg-1 in SO, VL, and TA, espectively. Significant differences were observed in IMCL and EMCL pairwise comparisons in SO, L, and TA (p ≤ 0.05). Strong correlations were observed between total fat fractions from 1H-MRS and Dixon MRI for VL (r = 0.794), SO (r = 0.655), and TA (r = 0.897). Bland-Altman analysis between at fractions (FFMRS and FFMRI) showed good agreement with small limits of agreement (LoA): bias = - .21% (LoA: -1.12% to 0.69%) in VL, bias = 0.025% (LoA: -1.28% to 1.33%) in SO, and bias = - .13% (LoA: -0.74% to 0.47%) in TA. The results of this study demonstrate the variation in muscle fiber orientation and lipid concentrations in these three skeletal muscle types.
KW - chemical shift
KW - diffusion tensor imaging
KW - intramyocellular lipids
KW - pennation angle
KW - proton magnetic resonance spectroscopy
KW - soleus
KW - tibialis anterior
KW - two-point Dixon magnetic resonance imaging
KW - vastus lateralis
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U2 - 10.1117/1.JMI.2.2.026002
DO - 10.1117/1.JMI.2.2.026002
M3 - Article
C2 - 26158115
AN - SCOPUS:84978043971
SN - 0720-048X
VL - 2
JO - Journal of Medical Imaging
JF - Journal of Medical Imaging
IS - 2
M1 - 026002
ER -