Assessment of lipids in skeletal muscle by LCModel and AMARES.
OBJECTIVE
To process single voxel spectra of the human skeletal muscle by using an advanced method for accurate, robust, and efficient spectral fitting (AMARES) and by linear combination of model spectra (LCModel). To determine absolute concentrations of extra- (EMCL) and intramyocellular lipids (IMCL).


METHODS
Single-voxel proton magnetic resonance spectroscopy (PRESS) was used to obtain the spectra of the calf muscles. Unsuppressed water line was used as a concentration reference. A new prior knowledge for AMARES was proposed to estimate the concentrations of EMCL and IMCL. The prior knowledge was derived from the spectrum of vegetable oil. The results were compared with the values estimated by LCModel. Absolute concentrations of total lipid content in millimoles per kilogram wet weight were used for the comparisons.


RESULTS
Absolute concentrations of total lipid content in skeletal muscle were estimated by AMARES and LCModel. Very good correlation of the total fat (EMCL + IMCL) and IMCL concentrations was achieved between both data processing approaches.


CONCLUSIONS
Assessment the absolute concentrations of muscular lipids by AMARES and LCModel can be performed with comparable accuracy.
Department of Radiology, Uppsala University Hospital, Uppsala, Sweden. jan.weis@radiol.uu.se
Jan
J
Weis
Lars
L
Johansson
Francisco
F
Ortiz-Nieto
Håkan
H
Ahlström
D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D000465:Algorithms; D015992:Body Mass Index; D006801:Humans; D016014:Linear Models; D008055:Lipids / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D018482:Muscle, Skeletal / Q000378:metabolism*; D009132:Muscles / Q000473:pathology; D015203:Reproducibility of Results; D012984:Software
D008055:Lipids