title: Assessment of lipids in skeletal muscle by high-resolution spectroscopic imaging using fat as the internal standard: comparison with water referenced spectroscopy.
abstract: The main purpose of the study was to compare proton (1H) single-voxel MR spectroscopy (MRS) with high-spatial-resolution spectroscopic imaging (MRSI) to determine the lipid content in human skeletal muscle. Unsuppressed water line was used as a concentration reference in the processing of single-voxel spectra. The spectrum from yellow bone marrow with a 100% fat content and probe with the vegetable oil served as internal and external reference for high-spatial-resolution MRSI, respectively. Very good correlation was found between lipid concentrations measured by water referenced single-voxel MRS and high-spatial-resolution MRSI with yellow bone marrow as the internal standard. Excellent correlation was found between total lipid concentrations estimated by high-spatial-resolution MRSI with vegetable oil as the external fat standard and yellow bone marrow as the internal reference. From comparison of single-voxel MRS and MRSI approaches, it follows that relaxation correction of the reference water and methylene fat line is inevitable in processing the standard single-voxel spectra. The high-resolution MRSI approach is recommended to avoid the problem of relaxation corrections and enables using vegetable oil as the external fat standard.
authors.affiliation: Department of Radiology, Uppsala University Hospital, Uppsala, Sweden. jan.weis@radiol.uu.se
authors.forename: J
authors.initials: J
authors.lastname: Weis
authors.forename: L
authors.initials: L
authors.lastname: Johansson
authors.forename: F
authors.initials: F
authors.lastname: Ortiz-Nieto
authors.forename: H
authors.initials: H
authors.lastname: Ahlström
mesh_terms: D000328:Adult; D006801:Humans; D008055:Lipids / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000737:chemistry*
chemical_list: D008055:Lipids