Proton magnetic resonance spectroscopy of skeletal muscle: A comparison of two quantitation techniques

Rationale and objectives The aim of this study was to develop and compare two methods for quantification of metabolite concentrations in human skeletal muscle using phased-array receiver coils at 3 T. Materials and methods Water suppressed and un-suppressed spectra were recorded from the quadriceps muscle (vastus medialis) in 8 healthy adult volunteers, and from a calibration phantom containing 69 mM/L N-acetyl aspartate. Using the phantom replacement technique, trimethylamine specifically [TMA] and creatine [Cr] concentrations were estimated, and compared to those values obtained by using the water reference method. Results Quadriceps [TMA] concentrations were 9.5 ± 2.4 and 9.6 ± 4.1 mmol/kg wet weight using the phantom replacement and water referencing methods respectively, while [Cr] concentrations were 26.8 ± 12.2 and 24.1 ± 5.3 mmol/kg wet weight respectively. Conclusions Reasonable agreement between water referencing and phantom replacement methods was found, although for [Cr] variation was significantly higher for the phantom replacement technique. The relative advantages and disadvantages of each approach are discussed.