Measurement of intramyocellular lipid levels with 2-D magnetic resonance spectroscopic imaging at 1.5 T

Abstract

Intramyocellular lipid (IMCL) plays an important role in the study of metabolism in vivo. Magnetic resonance spectroscopy (MRS) studies of IMCL are usually performed with clinical 1.5-T magnetic resonance imaging (MRI) systems and have employed the single-voxel MRS technique. The present study reports the results of our systematic evaluation of the ability of single- and multi-voxel MRS to yield high-quality, contamination-free IMCL levels from the tibialis anterior (TA) muscle. A clinical, 1.5-T, whole-body MRI scanner was used to measure IMCL with a standard knee coil, head coil, or a 3-cm receive-only surface coil with a body coil transmit. Excellent IMCL spectra were obtained in healthy males in only 8 min from multiple 0.25-cm(3) voxels using the surface coil receive/body coil transmit in conjunction with the standard PRESS spectroscopic imaging (SI) technique. This approach provided the spatial resolution and voxel placement flexibility permitting optimal separation of IMCL and extramyocellular lipid. Our findings demonstrate the potential of the SI approach.

Figures

Fig. 1

Spectrum of single-voxel magnetic resonance spectroscopy (MRS). Cho, choline; Cr, creatine; IMCL, intramyocellular lipid; EMCL, extramyocellular lipid

Fig. 2

Overlay of 2-D magnetic resonance spectroscopy (MRS) on a coronal magnetic resonance imaging (MRI) scan of a male subject’s right calf. The bone in the middle of the image is the tibia, the muscle to the right of the bone is the tibialis muscle

Fig. 3

Spectrum from a SI voxel in the tibialis anterior muscle of a male subject. The experimental spectrum has been fitted to a sum of Lorentzian lines. Cho, choline; Cr, creatine; IMCL, intramyocellular lipid; EMCL, extramyocellular lipid