TY - JOUR
T1 - 1H MRS of intramyocellular lipids in soleus muscle at 7 T
T2 - Spectral simplification by using long echo times without water suppression
AU - Ren, Jimin
AU - Sherry, A. Dean
AU - Malloy, Craig R.
PY - 2010/9
Y1 - 2010/9
N2 - The popular short echo time 1H MR spectroscopy acquisition method for detection of intramyocellular lipids suffers from spectral overlap due to the large, broad, and asymmetric extramyocellular lipid signals, the time-consuming practice of selecting "lean" voxels for spectroscopy, and the overlap of the extramyocellular lipid signal with the creatine methyl 1H signal at ∼3 parts per million (ppm), commonly used as an internal standard. Using an alternative acquisition strategy, spectra with well-resolved intramyocellular lipids resonances were acquired from large volumes (10 to 15 mL) of human soleus muscle in less than 5 min by single-voxel 7-T 1H MR spectroscopy, using an echo time of 280 ms. From the high-resolution spectra, an average intramyocellular lipid concentration of 7.7 ± 3.5 mmol/kg muscle was found for 25 healthy subjects (male/female 17/8; age 29.4 ± 6.6 years). Since water suppression was not required, the 1H signals from unsaturated intracellular triglycerides at about 5.3 ppm were easily detected, which, in combination with the well-determined - (CH2)n- /CH3 intensity ratio at long echo time, enabled assessment of the composition of triglycerides in the intramyocellular lipids compartment. Long-echo single-voxel spectroscopy at 7 T offers rapid and convenient acquisition of high-resolution spectra from human soleus muscle.
AB - The popular short echo time 1H MR spectroscopy acquisition method for detection of intramyocellular lipids suffers from spectral overlap due to the large, broad, and asymmetric extramyocellular lipid signals, the time-consuming practice of selecting "lean" voxels for spectroscopy, and the overlap of the extramyocellular lipid signal with the creatine methyl 1H signal at ∼3 parts per million (ppm), commonly used as an internal standard. Using an alternative acquisition strategy, spectra with well-resolved intramyocellular lipids resonances were acquired from large volumes (10 to 15 mL) of human soleus muscle in less than 5 min by single-voxel 7-T 1H MR spectroscopy, using an echo time of 280 ms. From the high-resolution spectra, an average intramyocellular lipid concentration of 7.7 ± 3.5 mmol/kg muscle was found for 25 healthy subjects (male/female 17/8; age 29.4 ± 6.6 years). Since water suppression was not required, the 1H signals from unsaturated intracellular triglycerides at about 5.3 ppm were easily detected, which, in combination with the well-determined - (CH2)n- /CH3 intensity ratio at long echo time, enabled assessment of the composition of triglycerides in the intramyocellular lipids compartment. Long-echo single-voxel spectroscopy at 7 T offers rapid and convenient acquisition of high-resolution spectra from human soleus muscle.
KW - Creatine
KW - Fatty acids
KW - Intramyocellular lipids
KW - Magnetic resonance spectroscopy
KW - Skeletal muscle
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U2 - 10.1002/mrm.22345
DO - 10.1002/mrm.22345
M3 - Article
C2 - 20578068
AN - SCOPUS:77956370937
VL - 64
SP - 662
EP - 671
JO - Magnetic Resonance in Medicine
JF - Magnetic Resonance in Medicine
SN - 0740-3194
IS - 3
ER -