Li Xiao1,2, Ed X. Wu1,2
1Laboratory of Biomedical Imaging & Signal Processing, the University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of; 2Department of Electrical & Electronic Engineering, the University of Hong Kong, Hong Kong, Hong Kong SAR, China, People's Republic of
Recognizing the correlation between insulin sensitivity and intramyocellular lipid (IMCL) level, non-invasive 1H MRS assessment of IMCLs has been extensively pursued. One major technical challenge in such IMCL quantitation is the spectral overlap and contamination by the large, broad and muscle orientation dependent extramyocellular lipid (EMCL) spectrum. Motivated by their difference in microscopic diffusion environment, we characterized the diffusion properties of IMCLs and EMCLs both ex vivo and in vivo. Our results demonstrated that EMCLs have significantly higher diffusivity, and they can be reliably suppressed via diffusion weighting while IMCLs remain visible. The proposed approach can be readily employed in study of human skeletal muscles in vivo, providing more reliable IMCL quantitation in MRS/MRI investigation of obesity and diabetes.