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.
- Fatty acids
- Intramyocellular lipids
- Magnetic resonance spectroscopy
- Skeletal muscle
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging